APA vs MLA - Differences Between Format And Citation Style

Working on a paper and thinking which formatting style to use? Confused between APA and MLA formatting? You are at the right place!! There are five major types of academic referencing styles: APA, MLA, Chicago, Oxford and Harvard. APA and MLA citation formats are probably the most commonly used referencing styles. Quick Links 1. What is a Citation and Citation Style? 2. APA vs MLA - What are the Differences? 2.1 APA Title Page vs MLA Title Page 2.2 APA PAper Format vs MLA Paper Format 2.3 APA vs MLA Citation 2.4 APA vs MLA In-Text Citation 2.5 APA vs MLA Headings and Subheadings 2.6 APA vs MLA References 2.7 APA vs MLA Bibliography 1. What is a Citation and Citation Style? Before moving forward with APA and MLA style guides and differences between them, you need to learn what a citation and citation style is. A citation is added into the academic papers and essays to refer back to the source of information and to credit the original author. It includes the name of the author, date of publication, name of the publisher, year of publication, page number, in case of books, anthologies and journals, name of the journal, edition, DOI (Digital Object Identifier) and the online source from where the data is retrieved. A citation is important to avoid plagiarism and to add credibility to your academic work. Universally, there are three main types of citation styles: APA, MLA and Chicago. 2. APA vs MLA - What are the Differences? APA format citation is similar to MLA format in quite some things like both of them use font type and size, Times New Roman 12pt, margins are one inch all around and the paper is double spaced. However, where they have some similar aspects, there are a number of differences between them that could not be avoided. Learn and follow them completely if you do not want your teacher to minus your score. Talking about the APA vs MLA points, both of these referencing styles have different histories, originations and their purposes of development. Researchers and experts developed these referencing styles to support particular fields of study. 2.1. APA Title Page vs MLA Title Page APA style papers and essays have a separate title page that is formatted in the respective style. The main things to add in the APA citation style title page are: Running Head or Title of the page; mentioning the main idea of the paper and not the whole topic Main topic, author's name and institute's name; centered on the page, 12pt, Times New Roman font style, double spaced and without any underlines, bolds and italics 1-inch margin on all four sides MLA paper does not require any separate title page and, generally, the author's name, instructor's name, department and the date of submission are mentioned on the first page of the assignment. The paper starts immediately after these details and with a centered paper title. 2.2 APA Paper Format vs MLA Paper Format Though both the citation styles share some common traits, they do have some differences in their formats. The paper presentation in both the styles is the same as both of them have 12pt Times New Roman font size and style, 1-inch margin on all four sides of the paper and double spaced. All the paragraphs are indented and the paper must contain proper, and accordingly, incites to credit the paraphrase and direct quotes. One of the main APA and MLA differences is that in the MLA, writers add endnotes and footnotes to give additional information. In APA style paper, no footnotes are added. 2.3 APA vs MLA Citation A major APA vs MLA format characteristic is the style of referencing that is used in both of them. The references in the APA format is added in the 'References' page while the cited works in MLA are added in the 'Works Cited' page. For Hardcover Books In both APA and MLA formats, the books' authors, year of publishing, publisher and place of publishing are added, but in a different order. APA The author's last name followed by the initial of the first name and year of publication, italicized name of the book, city, state and publisher are added. James, H. (1937). The ambassadors. New York, NY: Scribner. MLA For MLA print book citation method, the last name is followed by the first name of the author, the main title of the work, city, publisher, the year of publication and print, to indicate the kind of book. Dickens, Charles. Great Expectations. New York: Dodd, Mead, 1942. Print. For Online Books Online books citation differs in the way that the online source, the web link, is added into the citation so that it is accessible afterwards also. APA The following format is followed, Porter, R. (1994). London, a social history. Retrieved from http://books.google.com MLA For MLA online book citation, the following order is followed, Bodnar, Kipp, and Jeffrey L. Cohen. The B2B Social Media Book. Google Books. N.p., n.d. Web. 20 Dec. 2012. For Books from a Database Apart from hardcovers and print versions, there are many books that are available in the databases, line websites and online publishing sites and could be accessed online. For them, link to the main database is added into the reference. APA For APA, the whole format is the same but the link of the website is added. Bloom, H. (1986). American women poets. Retrieved from http://www.infobasepublishing.com. MLA The whole format is the same except only the source, web is mentioned with the date and URL of the source. Morem, Susan. 101 Tips for Graduates. New York: Ferguson, 2005. Infobase Publishing eBooks. Web. 16 Mar. 2010. http://www.infobasepublishing.com For Websites and Blogs For most of the students, online sources are a way to go. People now prefer and rely on digital mediums than print books and other sources. To highlight more of the APA vs MLA features, we are adding how to cite your online sources here. APA For websites, only its link is added, without the date on which it was accessed, along with the author and date of publishing. Cain, K. (2012, June 29). The Negative effects of Facebook on communication. Social Media Today RSS. Retrieved from http://socialmediatoday.com For blogs and articles, follow the following structure. China, The American Press, and the State Department [Web log post]. (2013, January 3). Retrieved from Schonfeld, E. (2010, May 3). MLA One core difference that we would like to mention and add in this APA vs MLA argument is that where APA follows separate format for websites and blogs, MLA follows the same for both. Cain, Kevin. "The Negative Effects of Facebook on Communication." Social Media Today RSS N.p., 29 June 2012. Web. 02 Jan. 2013. For Print Journals Academic journals are often used by students to learn about new trends and studies and to stay up-to-date also. When adding journals in your paper, or study, make sure that you follow proper citation guidelines to ensure its flawless structure. Our complete guide on MLA Format with sample paper and further examples will help you understand it further. APA To add citations and references for journals, add volume and issue number and page numbers along with the date of publication, the author's name and paper title. Jacoby, W. G. (1994). Public attitudes toward government spending. American Journal of Political Science, 38(2), 336-361. MLA For MLA, all the details mentioned for APA paper format will be added except that the order of mention will be different. Jacoby, William G. "Public Attitudes Toward Government Spending." American Journal of Political Science 38.2 (1994): 336-61. Print. For Online Journals Besides being available in libraries, academic journals are available online as well. If you are here to look for a guide to know about how to cite online journals, follow the following structure. APA Along with the previously mentioned details, in the online version, the link of the main website, paper tile and doi (Digital Object identifier), or the date of retrieval is added. Poiger, U. G. (1996). Rock 'n' roll, female sexuality, and the Cold War Battle over German Identities. The Journal of Modern Language, 68(3), 577. doi:10.1086/245343 MLA The date of retrieval and the title of the website are added at the end of the reference. Poiger, Uta G. "Rock 'n' Roll, Female Sexuality, and the Cold War Battle over German Identities." The Journal of Modern Language 68.3 (1996): 577. JSTOR. Web. 2 Jan. 2013. For Database Journals Apart from print and online journals that you can find for your paper's assistance, to format a paper from a database, use the following methods. APA To know the format, follow the following structure, Davis, E. (1932). New chapters in American psychological history. The Science News-Letter, 22(605), 306-307. doi: 10.2307/3907973 MLA Follow the following structure to add your citations for online academic journals. Jacoby, William G. "Public Attitudes Toward Government Spending." American Journal of Political Science 38.2 (1994): 336-61. JSTOR. Web. 23 Apr. 2010. 2.4 APA vs MLA In-text Citation Found a great quote or phrase? Great. Adding direct quotes and phrases and paraphrased content is a great way of supporting your research in social sciences. However, the added information must be cited and referenced properly. For a Single Author For APA in-text citation, the last name of the author followed by the date of publication and page number, in case of books or journals and specific parts of a study, is presented in parentheses. "Darwin's theory of evolution is flawed and inconsistent. (Shawn, 2015, p. 15)." In case the author's name is mentioned in the sentence, just add the year in front of the writer's name and the page number at the end of the sentence. Shawn (2015) argues that Darwin's evolution is flawed and inconsistent (p. 15). For MLA style, the last name of the author, followed by the page of the book or journal, if any, is presented in parenthesis. "Darwin's theory of evolution is flawed and inconsistent. (Shawn 15)." If the author's name is added to the sentence then the page number is mentioned only. Shawn (2015) argues that Darwin's evolution is flawed and inconsistent (15). For Multiple Authors In APA format, all the last names of the authors and year of publication are mentioned in the first in-text, separated by a comma and ampersand. Greenhouse effect is one of the key players in increasing global warming (Williams, Smith, Shaw, 2015). For every other subsequent in-text, only the first name is added, followed by et al and the year of publication. Global warming is affecting the environment on a large scale can be minimized by reducing our carbon footprint (Williams et al., 2015). For MLA paper citation, you do not need to add and mention all the writers in the first intext. Only the first author is mentioned while the others are cited as et al followed by the page number. By minimizing the use of plastic and non-biodegradable substances, the environmental hazards of carbon and global warming could be minimized to a large extent (Williams et al. 50). In case the authors are mentioned in the sentence, only page number will be mentioned at the end of the sentence. For Sources Without an Author Coming across a source without any author is probably the most frustrating thing for a student but it is common when you are working with digital images, movies and videos, dictionaries and encyclopedias and online web pages where authors are not mentioned. In APA, in case you do not find the author, add the first few words of the study and the year of publication. According to a new research, human cloning may be the future of human advancement ("Genetics and Genes," 2014). If you have mentioned the title of the study in the content then add the year of publication only. According to "Genetics and Genes" study (2014), human cloning may be the future of human advancement. In case of no author name in MLA citation, the name of the work is used in parentheses and quotation marks. If the title is too long, shorten the title but make sure that the words are the same as added and mentioned in the Works Cited. "From the moment you hold your baby in your arms you will never be the same. You might long for the person you were before, when you had freedom and time and nothing in particular to worry about" ("The Last Time"). For online sources, in both APA and MLA, the same format of author's name and date of publication is followed. In case nothing is mentioned, just add the title of the article, or paper. Make sure that you follow the right in-text citation style. 2.5 APA vs MLA Headings and Subheadings MLA does not follow a tightly knitted headings and subheadings system as it is mostly used by the students of literature and other social arts subjects. These subjects do not much of headings and subheadings and follow the paragraph system only. However, if you still want to divide your paper into sections, there is a suggested format for it. 1. Heading 1 1.1. Subheading 1 1.2. Subheading 2 2. Heading 2 2.1. Subheading 1 2.2. Subheading 2 This table is just for reference and to give you an idea only; you should use whatever works best for you but make sure that it is consistent throughout the paper. APA format has a well-defined headings and subheadings system; because this is followed by the scholars of scientific studies and they use headings and sections to organize their work, this format has a set guideline for sections. A usual APA format for headings and subheadings is: Level 1 Heading Level 2 Heading Level 3 Heading. Level 4 Heading. Level 5 Heading. When adding headings and subheadings in your APA style paper, consider these and follow the structure carefully. 2.6 APA vs MLA References In an APA paper or essay, the references are added at the end of the paper and under the 'References' title. The works used as references in an MLA paper are added under the 'Works Cited' title. All the citations and references are organized in alphabetical order. 2.7 APA vs MLA Bibliography None of the APA or MLA calls for bibliography as a must. They treat References and Works Cited pages as thorough references. However, if you do need to add the bibliography, follow the citation structure as prescribed by your respective paper's citation format. Still confused? It is completely normal to get confused with all these technicalities. We are here to help you with that. 5StarEssays is a professional essay writing service delivering quality and cheap research papers. We are always here to help you understand your papers in a better way and to give effective and timely answer to your 'write my essay' request. We know that you need fast, reliable and affordable help and we are here to provide you academic assistance. Place your orderand get your high-quality paper written by an expert writer.

Romeo and Juliet Tragedy Essays

Romeo and Juliet Tragedy Essays Romeo and Juliet Tragedy Paper Romeo and Juliet Tragedy Paper Essay Topic: Romeo and Juliet It is my opinion that no one person can be held responsible for the tragic deaths of the two lovers, Romeo and Juliet. Rather it is a combination of people and circumstances that contrive to form a tragic ending. Obviously, Romeo and Juliet is a tragedy, and thus has all the generic features of a tragedy; that there is a fatal flaw on the part of the main characters, in this case their passionate love at first sight for each other, Did my heart love till now? This passionate love means the two lovers cannot be separated, and their desperation to be together could be the reason for their plight. Alternatively, it could also be argued that Shakespeare built up dramatic expectation, via prophetic fallacy and short scenes accelerating to a climax, that the death was necessary as a dramatic ending. This structure can be clearly seen throughout the play as a whole as Shakespeare uses lower status characters (talking in prose) usually to speed up the pace, using riots and conflicts, whereas he uses the higher status characters (talking in verse) at balls or parties to slow down the pace and deepen the play. Therefore, due to Shakespeares deliberately convoluted plot, it is imperative to discuss each topic in turn, evaluating how and to what extent, each factor was responsible; starting with, arguably, one of the most important reasons; fate, or chance. Fate, or chance, was an accepted philosophical belief in Elizabethan England, and both were linked to astrology; the belief that you can see the future in the planets, Some consequence yet hanging in the stars! The belief that the two lovers have a preordained destiny, i. . that the two, star crossd lovers cannot change their fate, recurs frequently throughout the play. Shakespeares references to fate are, almost without exception, asides, Some consequence yet hanging in the stars, which meant that the character was talking to himself (and therefore the audience), and showed that Shakespeare really wanted to emphasise this point in the play to the onlookers. On looking through the play, I found there were far more references to fate in t he first two acts than the last ones. This may be because these references to fate are coupled with prophetic fallacies; which are used to build tension and dramatic expectation, to maintain interest in the first half and then allow the omniscient audience to see the inevitable consequences. I believe Shakespeare used fate as the classic medium to create the fall from power, another traditional feature of a tragedy, and then used the portents to allow the pair to see their unavoidable downfall. This fateful incurrence provides the struggle of the play; the lovers conflict against their, death-marked loves. As a subsection of fate, the references to chance specifically are fewer, and in a direct contrast to the references to fate, appear mainly at the culmination of the play. This lends rather well to the feeling of chaos, as chance is a much more random idea than fate, and gives the impression that anarchy is at work. This set up has also been chosen as a way of showing that there could be more than one person behind the tragic deaths. That is, Shakespeare has deliberately given the final two scenes a chaotic feel to illustrate the convoluted plot lines and the intertwining motives each character has, especially true of the Friar Lawrence. The only real reference to chance (although it can be argued it is fate at work) is the failure of Friar John to deliver the letter, I could not send it! Linked to Fate, is social pressure, during the play, Shakespeare uses social pressure as an agency for fate; i. e. a way to focus the situation and explaining why the lovers cannot be together. It can be argued that this is the most important reason as without a conflict and inhibitor there would be no play as Romeo and Juliet could just be together. However, social pressure is a more modern idea and as such it is unlikely that Shakespeare purposely decided to use it, and I feel probably thought of it is the feud; indeed it is only with hindsight that we can see its effect. Shakespeare emphasise this point like most of the others from the very beginning of the play, dog of the house of Montague, and even before that in the prologue, ancient grudge break to new mutiny. This first scene cleverly reflects Act 3 scene 1, but Shakespeare has changed the roles so that Romeo discards his pacifist views and is provoked into fire-eyed fury. When Shakespeare draws references to Italy, he may be reflecting the traditional, and rather stereotypical, view of Italians as all having private vendettas or feuds. However, to a certain extent it works as Shakespeare is using a literary technique of setting the events in a place the Elizabethan audience would not know about apart from what theyve been told. In particular, by leaving the facts uncle ar about the ancient grudge, one begins to feel that perhaps there wasnt one, or that it has escalated out f all control. This is used for dramatic irony, as it is in inverse proportion to the amount of destruction incurred by the end of the final scene, all are punished! Another reason which Shakespeare decided to introduce was the Friars own motives. He says, to Romeo, that he wants to turn your households rancour to pure love, but he seems wary to allow the lovers to wed in public and appears more intent of the joining of the two households than that the two lovers are together, for this alliance may so happy prove. I believe that Shakespeare has left this reason in deliberately to offer an alternative view, and to give more variety to the end scene. Shakespeare also displays an ulterior personality trait of the Friar as he appears reluctant to be found with the bodies and hurries from Capels monument rather than be caught, and when he is the language he uses reflects the way that he is prepared to tell all. The language he uses is direct, there are no puns and little imagery and the language is non-theological when compared to his behaviour in his cell, Benedicte! and Holy Saint Francis! which demonstrates how unwilling he is to be dishonoured. Fellow characters echo this sentiment, and Juliet exclaims, What if it be a poison which the Friar subtly hath ministered to have me dead? This statement turns out to be ironical as although the potion is not a poison, the Friars plans do culminate in her and Romeos death. The friar, himself raises an interesting point as a cause, he blames the rude will of human nature (Act 2 scene 3) and disclaims that self-centredness results in evil if it gains priority over grace. Maybe, therefore, it is only human nature to cause such sufferings. Another point, which recurs throughout the play, is the patriarchal dominance of the society which the play is set in. In this community fathers had absolute sway over their daughters and gave them away to whosoever they chose, and were offended if they refused. It could have been the fathers stubbornness that the two were unable to join. This point is linked to the idea about the pointlessness of the feud; it was the fathers as head of the families who were the main upholders of the feud, and they never mention the reason for their doing so. As Elizabethan society was so patriarchal, it would therefore have been a dramatic point that Shakespeare was making when he uses Juliets sarcasm as a device to fight back at her father, It is an honour I dream not of! In the context of this play, this means that Capulet feels it is his right to pressurise Juliet, go with Paris to Saint Peters church, Or I will drag thee on a hurdle thither. The separation between Juliet and her father is repeated in the Lady Capulet, and the two seem uneasy when together. Shakespeare demonstrates this point by splitting a technique such as repetition across the two characters, so the two appear to be interrupting each other for example, Lady Capulet: The county Paris, at Saint Peters Church Shall happily make thee a joyful bride. Juliet: Now by Saint Peters Church and Peter too, He shall not make me there a joyful bride. Such repetition increases the tightening tension of the plot and gives an additional insight into the pairs characters. My final point is perhaps the most obvious, that it is the love or passion of Romeo and Juliet themselves that causes their death. The two lovers are so madly in love that are too hasty and Shakespeare emphasises this by short scenes accelerating to an abrupt climax. It can be argued that the structure of the play therefore reflects the pairs turbulent relations as when they are harmonious the pace is slowed, and this is then sped up when the two are desperately seeking each other. Perhaps the tragic ending is Shakespeares way of rebuking both love at first sight and the artificial, chivalric love between Rosaline and Romeo. In conclusion, as can be seen from the discussed reasons; there are, as with all of Shakespeares plays a multitude of factors, which are all equally valid and viable. Also, all of Shakespeares language is intentional, so he is able to cleverly link both individual passages and whole scenes to the play as a whole. However, Shakespeare emphasises some more than others and in this respect I believe it is fate, which is the most predominantly mentioned of the factors. This is consistently mentioned by Shakespeare and lends itself to the play as a whole well. As previously discussed it lends a feeling of impending doom, and inevitable tragedy to the play. This factor could have become too linear, so Shakespeare introduced the idea of chance, which adds a random and chaotic air to the play. Also, all of Shakespeares language is intentional, so he is able to cleverly link both individual passages and whole scenes to the play as a whole.

No topic Essay Example | Topics and Well Written Essays - 500 words - 23

No topic - Essay Example Although in reality this short piece of writing encompasses and deals with some major aspects of the life of human beings such success, failures and fears. The writer begins the story with a tone of zeal for life when she talks about the long winter days where people plan their routines on hourly basis. â€Å"It never got very dark. Your life parted and opened in sunlight† (Dillard, p. 94). It implies that the writer’s life as well as the lives of her fellow human beings was a busy one where everyone was a participant in the marathon of success. However some were highly successful like Rahm who had the power to entrance and enchant people with his agility and experience while others were on a lesser level like other pilots who knew the same acrobatics but could not perform all of them at once. Since the very beginning of the story Dillard provides the readers with the comparison between the lives of successful and the lesser successful people in life which also inspires an individual to work harder and better to prosper. As it is also apparent from the antics of the blue swallow as well, â€Å"the swallow climbed high ov er the runway, held its wings oddly, tipped them†¦ the inspired swallow† (Dillard, p. 97). Dillard also explores the psychological impact of fear that leads to failure and the insecurities an individual might harbor regardless of his success and prosperity in life. â€Å"Sitting invisible at the controls of a distant plane, he became an agent and the instrument of art†¦ robed in the plane he was featureless as a priest† (Dillard, p. 110). These lines highlight that success does not make an individual perfect or invincible every person has his fair share of fears, insecurities and troubles however the intelligent ones just cover their weaknesses better than the lesser intelligent ones. Furthermore regardless of the dexterity and expertise that one might have it does not guarantee that they are

Philosophy Assignment Example | Topics and Well Written Essays - 750 words - 5

Philosophy - Assignment Example She responded with, â€Å"Being gay isn’t like trying on a pair of jeans, deciding you don’t like them, and then putting them back on the shelf. If you’re gay, you’re gay. There’s no changing that.† When I asked her if she was discriminated against for her sexual orientation, she answered with a simple yes, not going into further detail. Finally, I asked her if she would be accepting if her child started dating someone of the same sex. She said of course, and jokingly said she wouldn’t be accepting if they dated someone of the opposite sex. She went on to say that she would be supportive of whoever who child decided to date. Ashley seemed to be one of many gay people that did not seem even the slightest bit abashed to openly discuss her sexual orientation. She answered the questions with pride and dignity; she was very open in her responses and did not seem the least bit uncomfortable. She clearly feels strongly for the equality of gay people. Her response to my final question had been amusing. Even though it was said with humor, it showed a side that is seldom revealed about gay people: while heterosexual couples feel that homosexuality is odd and abnormal, the gay community often feels the same way about heterosexual couples. It was an interesting experience for me to see the two different sides of the story. Lauren is a 17 year old black female. When I asked her if gay people should be allowed to marry, she answered with, â€Å"What difference does it make if they are the same sex? Marriage is love, not gender.† I then asked if gay couples should be given full civil rights. She answered with a yes, explaining that America stands on equality and should extend the same rights to everyone, regardless of sexual orientation. I asked her if being gay was something that could be changed. Similar to Ashley, she said that she believed that people did not really have a choice, and that many people try to date the opposite sex

Critique of Kokomo sung by the Beach Boys Essay

Critique of Kokomo sung by the Beach Boys - Essay Example Mike Love added the "Aruba, Jamaica" part and changed the line "Thats where we used to go" to "Thats where we want to go."† (par. 5). The song was played in the movie Cocktail which featured Tom Cruise. It was ranked number 1 in the US Billboard Hot 100 number-one singles (DeKnock, 1988). The pitch is an element of tone, determined by the frequency of vibration (Free Dictionary, par. 1). The song was delivered in well balanced vocal tones and vibration accompanied by steel drums, acoustic guitar, bass and saxophone. The pitch of the voice of singers, Mike Love and Carl Wilson, were harmonious and well blended. The intensity or loudness was average with vocals and instrumentation concocted to arrive at a unified musical structure. High quality exudes from the distinctive overtones heard from the drums at the background and the guitar. In an article written by Jones on Understanding Vibrato, he defined vibrato as "slight variation of pitch resulting from the free oscillation of the vocal cords". This free oscillation of the vocal cords results from (1) an open pharynx or what many call the "open throat" along with (2) healthy "closure of the cords" I consider that vibrato is a result of these two opposites working together: open throat and closed cords. (3) Another majo r factor to be considered in regard to vibrato is the even sub-glottic breath pressure.

On the Implant Communication and MAC Protocols for a WBAN

On the Implant Communication and MAC Protocols for a WBAN Abstract Recent advances in micro-electro-mechanical systems (MEMS), wireless communication, low-power intelligent sensors, and semiconductor technologies have allowed the realization of a wireless body area network (WBAN). A WBAN provides unobtrusive health monitoring for a long period of time with real-time updates to the physician. It is widely used for ubiquitous healthcare, entertainment, and military applications. The implantable and wearable medical devices have several critical requirements such as power consumption, data rate, size, and low-power medium access control (MAC) protocols. This article consists of two parts: body implant communication, which is concerned with the communication to and from a human body using RF technology, and WBAN MAC protocols, which presents several low-power MAC protocols for a WBAN with useful guidelines. In body implant communication, the in-body radio frequency (RF) performance is affected considerably by the implants depth inside the human body as well as by the muscle and fat. We observe best performance at a depth of 3cm and not close to the human skin. Furthermore, the study of low-power MAC protocols highlights the most important aspects of developing a single, a low-power, and a reliable MAC protocol for a WBAN. Keywords: In-body, on-body, RF communication, Implant, WBAN 1. Introduction Cardiovascular diseases are the foremost cause of deaths in the United States and Europe since 1900. More than ten million people are affected in Europe, one million in the US, and twenty two million people in the world [1]. The number is projected to be triple by 2020, resulting in an expenditure of around 20% of the gross domestic product (GDP). The ratio is 17% in South Korea and 39% in the UK [2]. The healthcare expenditure in the US is expected to be increased from $2.9 trillion in 2009 to $4 trillion US dollars in 2015 [3]. The impending health crisis attracts researchers, industrialists, and economists towards optimal and quick health solutions. The non-intrusive and ambulatory health monitoring of patients vital signs with real time updates of medical records via internet provide economical solutions to the health care systems. A wireless body area network (WBAN) is becoming increasingly important for healthcare systems, sporting activities, and members of emergency as well as military services. WBAN is an integration of in-body (implants) and on-body (wearable) sensors that allow inexpensive, unobtrusive, and long-term health monitoring of a patient during normal daily activities for prolonged periods of time. In-body radio frequency (RF) communications have the potential to dramatically change the future of healthcare. For example, they allow an implanted pacemaker to regularly transmit performance data and the patients health status to the physician. However, the human body poses many wireless transmission challenges. This is partially conductive and consists of materials having different dielectric constants and characteristics impedance. The interface of muscles and fats may reflect the RF wave rather than transmitting it. The key elements of an RF-linked implant are the in-body antenna and the communi cation link performance. Also, in the case of many implants and wearable sensors, a low-power MAC protocol is required to accommodate the heterogeneous traffic in a power-efficient manner. This article is divided into two parts: body implant communication and WBAN MAC protocols. In the body implant communication part, we look at the RF communication link performance at various depths inside a human (artificial) body. In the MAC part, we review the existing low-power MAC protocols and discuss their pros and cons in the context of a WBAN. We further provide alternative MAC solutions for in-body and on-body communication systems. The rest of the article is divided into three sections. In section 2, we present a discussion on body implant communication including in-body electromagnetic induction, RF communication, antenna design, and the communication link performance. Section 3 discusses several low-power MAC protocols and realizes a need for a new, a low-power, and a reliable MAC protocol for a WBAN. The final section concludes our work. 2. Body Implant Communication There are several ways to communicate with an implant that includes the use of electromagnetic induction and RF technology. Both are wireless and their use depends on the application requirements. Further, the key elements of an RF-linked implant are the in-body antenna and the communication link performance. The following part discusses in-body electromagnetic induction, RF communication, antenna design, and the communication link performance. 2.1. In-body Electromagnetic Induction Several applications still use electromagnetic coupling to provide a communication link to an implant device. In this scheme, an external coil is held very close to the body that couples to a coil implanted just below the skin surface. The implant is powered by the coupled magnetic field and requires no battery for communication. Data is transferred from the implant by altering the impedance of the implanted loop that is detected by the external coil and electronics. This type of communication is commonly used to identify animals that have been injected with an electronic tag. Electromagnetic induction is used when continuous, long-term communication is required. The base band for electromagnetic communication is typically 13.56 MHz or 28 MHz, with other frequencies also available. The choice of a particular band is subject to regulation for maximum specific absorption rate (SAR). The inductive coupling achieves best power transfer efficiency when uses large transmit and receive coil s. It, however, becomes less efficient when the space is an issue of the device is implanted deep inside the human body. Furthermore, inductive coupling technique does not support a very high data rate and cannot initiate a communication session from inside of the body. 2.2. In-body RF Communication Compared with the electromagnetic induction, RF communication dramatically increases bandwidth and supports a two-way data communication. The band designated for the in-body RF communication is medical implant communication service (MICS) band and is around 403 to 405 MHz. This band has a power limit of 25  µW in the air and is usually split into ten channels of 300 kHz bandwidth each. The human body is a medium that poses numerous wireless transmission challenges. It consists of various components that are not predictable and will change as the patient ages, gains or losses weight, or even changes posture. Values of dielectric constant (ÃŽ µr), conductivity (ÏÆ') and characteristic impedance (Zo) for some body tissue are given in table 1 [4]. This demonstrates that these two tissue types are very different. Also, the dielectric constant affects the wavelength of a signal. At 403 MHz, the wavelength in the air is 744mm, but in muscle with ÃŽ µr = 50 the wavelength reduces to 105mm, which helps in designing implanted antennas. 2.3. In-body Antenna Design A modern in-body antenna should be tuneable by using an intelligent transceiver and software routine. This enables the antenna coupling circuit to be optimised. Due to the frequency, and available volume, a non-resonant antenna is commonly used. It has a lower gain than a resonant antenna. This makes design of the antenna coupling circuit very important. Antenna options are dictated by the location of the implant. A patch antenna can be used when the implant is flat. Patch antennas are comprised of a flat insulating substrate coated on both sides with a conductor. The substrate is a body compatible material with a platinum or a platinum/iridium conductor. The upper surface is the active face and is connected to the transceiver. The connection to the transceiver needs to pass through the case where the hermetic seal is maintained, requiring a feed-through. The feed-through must have no filter capacitors present; these are common on other devices. An implanted patch antenna is electrically larger than its physical size because it is immersed in a high (ÃŽ µr) medium. It can be much larger electrically if the substrate is of higher (ÃŽ µr), such as titania or zirconia. A loop antenna can also be attached to the implant. This antenna operates mostly by the magnetic field, whereas the patch operates mostly by the electric field. The loop antenna delivers performance comparable to that of a dipole, but with a considerably smaller size. In addition, the magnetic permeability of muscle or fat is very similar to that of an air, unlike the dielectric constant that varies considerably. This property enables an antenna to be built and used with much less need for retuning. A loop antenna can be mounted on the case in a biocompatible structure. 2.4. In-body Link Performance The demonstration system consists of a base-station, an implant, antennas, and a controlling laptop. The base-station contains a printed circuit board (PCB) with a wakeup RF circuit, a Zarlink ZL70101 IC, and a micro-controller. It sends a wakeup signal on industrial, scientific, and medical (ISM) 2.4 GHz band to power up the implant to communicate. It also supports communication within the MICS band. The implant contains a Zarlink ZL70101 IC, a micro-controller, and a battery. The power limits of the wakeup signal for ISM and MICS bands transmitters are 100mW and 25  µW respectively. Experiments that measure the performance of an implant inside a living body are difficult to arrange. The alternative is to use 3D simulation software or a body phantom defined in [5]. The use of 3D simulation software is time consuming and hence practically not valuable. Therefore, measurements are generally performed using the body phantom and immersing a battery-powered implant into it [6]. Since no additional cables are attached to the test implant, the interference errors in the measurements are minimal. The body phantom is filled with a liquid that mimics the electrical properties of the human body tissues. The test environment is an anechoic chamber that includes a screened room. The interior walls of the room have sound-absorbent cones to minimize any reflections from walls or the floor that could distort the results. In real life, however, the results will be affected by the reflections from walls, desks, and other equipment and hardware. The body phantom is mounted on a woo den stand (non-conductive). The distance from the body phantom to the base-station is 3m. The MICS base-station dipole antenna is mounted on a stand. 1(a) shows the anechoic chamber with a body phantom (on the wooden stand), a log periodic test antenna (foreground), and a base-station dipole (right). The log periodic antenna is used to calculate the power radiated from the body phantom. A depth is defined as the horizontal distance between the outer skin of the phantom and the test implant. Vertical polarization of the implant is the case when the long side of the box and the patch antenna is vertical. The link performance is measured once the communication link is established. The measurements include the effective radiated power (ERP) from the implant, the received signal at the implant from the base-station, and the link quality. Measurements are made over a set distance with all the combinations of implant and test antenna polarisations, i.e., vertical-vertical (V-V), horizontal-vertical (H-V), vertical-horizontal (V-H), and horizontal-horizontal (H-H) polarisations. Typical results are shown in 1(b) where the ERP is calculated from the received signal power and the antenna characteristics. The measurement of the signal levels is done with the log periodic antenna and the spectrum analyzer. It can be seen in the that there is a significant difference in signal levels with polarisation combinations and depths. For a V-V polarisation, the ERP increases from a 1cm depth to a maximum between 2 and 7 cm, and then it decreases. The gradual increase is due to the simulated body acti ng as a parasitic antenna. The also shows how the signal level is affected by the depth with different polarisation. Such a test needs to be done with the antenna that is to be used in the final product. To measure the received signal at the implant, the Zarlink ZL70101 has an inbuilt receive signal strength indication (RSSI) function that gives a measure of the signal level detected. RSSI is a relative measurement with no calibration. The implant receives and measures a continuous wave signal transmitted by the base-station. In this case, the implant and the base-station antennas are vertically polarised. 1(c) shows an increase in the signal level at a depth between 3 and 4cm for a 15dec power. The power settings refer to the base-station and are cond to set the ERP to 25  µW. Signal levels are not valuable unless they are related to data transmission. One way to maintain the link quality is to measure the number of times the error correction is invoked during the transmission of 100 blocks of data. Two types of error correction codes, i.e., error correction code (ECC) and cyclic redundancy code (CRC) are invoked to maintain data integrity and reliability. The fewer ECC and CRC invocations result in better link quality. In 1(d), the error correction is lowest at a depth between 3 and 5 cm. A sample of ECC data collected at a 3cm implant depth is given in Table 2. The Count indicates the number of data blocks, the Time (ms) indicates the block transmission time, and the ECC indicates the number of times it is invoked. During the transmission of 100 blocks of data at a 3cm depth, the ECC is invoked 368 times, which is further equivalent to an average 3.68 times (as given in 1(d)). 2.5. Discussion The ERP, RSSI, as well as the ECC and CRC plots show that the implant demonstrates the best performance at a depth between 3 and 5 cm. The depth and position of an implant is not chosen for engineering performance but for the best clinical reasons. The implant designer must be aware of the possible losses through the human body. The attenuation and the parasitic antenna effects vary from patient to patient, with the position of the implant and with the time as the patient gains, or looses weight. Therefore, these factors need to be built into the link budget. 3. WBAN MAC Protocols Some of the common objectives in a WBAN are to achieve maximum throughput, minimum delay, and to maximize the network lifetime by controlling the main sources of energy waste, i.e., collision, idle listening, overhearing, and control packet overhead. A collision occurs when more than one packet transmits data at the same time. The collided packets have to be retransmitted, which consumes extra energy. The second source of energy waste is idle listening, meaning that a node listens to an idle channel to receive data. The third source is overhearing, i.e., to receive packets that are destined to other nodes. The last source is control packet overhead, meaning that control information area added to the payload. Minimal number of control packets should be used for data transmission. Generally MAC protocols are grouped into contention-based and schedule-based MAC protocols. In contention-based MAC protocols such as carrier sense multiple access/collision avoidance (CSMA/CA) protocols, nodes contend for the channel to transmit data. If the channel is busy, the node defers its transmission until it becomes idle. These protocols are scalable with no strict time synchronization constraint. However, they incur significant protocol overhead. In schedule-based protocols such as time division multiple access (TDMA) protocols, the channel is divided into time slots of fixed or variable duration. These slots are assigned to nodes and each node transmits during its slot period. These protocols are energy conserving protocols. Since the duty cycle of radio is reduced, there is no contention, idle listening and overhearing problems. But these protocols require frequent synchronization. Table 3 compares CSMA/CA and TDMA protocols. 3.1. WBAN MAC Requirements The most important attribute of a good MAC protocol for a WBAN is energy efficiency. In some applications, the device should support a battery life of months or years without interventions, while others may require a battery life of tens of hours due to the nature of the applications. For example, cardiac defibrillators and pacemakers should have a lifetime of more than 5 years, while swallowable camera pills have a lifetime of 12 hours. Power-efficient and flexible duty cycling techniques are required to minimize the idle listening, overhearing, packet collisions and control packet overhead. Furthermore, low duty cycle nodes should not receive frequent synchronization and control information (beacon frames) if they have no data to send or receive. The WBAN MAC should also support simultaneous operation on in-body (MICS) and on-body channels (ISM or UWB) at the same time. In other words, it should support multiple physical layer (Multi-PHYs) communication or MAC transparency. Other important factors are scalability and adaptability to changes in the network, delay, throughput, and bandwidth utilization. Changes in the network topology, the position of the human body, and the node density should be handled rapidly and successfully. The MAC protocol for a WBAN should consider the electrical properties of the human body and the diverse traffic nature of in-body and on-body nodes. For example, the data rate of in-body nodes varies, ranging from few kbps in pacemaker to several Mbps in capsular endoscope. In the following sections, we discuss proposed MAC protocols for a WBAN with useful guidelines. We also present a case study of IEEE 802.15.4, PB-TDMA, and S-MAC protocols for a WBAN using NS2 simulator. 3.2. Proposed MAC Protocols for a WBAN In this section, we study proposed MAC protocols for a WBAN followed by useful suggestions/comments. Many of the proposed MAC protocols are the extension of existing MAC protocols originally proposed for wireless sensor networks (WSNs). 3.2.1. IEEE 802.15.4 IEEE 802.15.4 has remained the main focus of many researchers during the past few years. Some of the main reasons of selecting IEEE 802.15.4 for a WBAN were low-power communication and support of low data rate WBAN applications. Nicolas et.al investigated the performance of a non-beacon IEEE 802.15.4 in [7], where low upload/download rates (mostly per hour) are considered. They concluded that the non-beacon IEEE 802.15.4 results in 10 to 15 years sensor lifetime for low data rate and asymmetric WBAN traffic. However, their work considers data transmission on the basis of periodic intervals which is not a perfect scenario in a real WBAN. Furthermore, the data rate of in-body and on-body nodes are not always low, i.e., it ranges from 10 Kbps to 10 Mbps, and hence reduces the lifetime of the sensor nodes. Li et.al studied the behavior of slotted and unslotted CSMA/CA mechanisms and concluded that the unslotted mechanism performs better than the slotted one in terms of throughput and lat ency but with high cost of power consumption [8]. Intel Corporation conducted a series of experiments to analyze the performance of IEEE 802.15.4 for a WBAN [9]. They deployed a number of Intel Mote 2 [10] nodes on chest, waist, and the right ankle. Table 4 shows the throughput at a 0dBm transmit power when a person is standing and sitting on a chair. The connection between ankle and waist cannot be established, even for a short distance of 1.5m. All other connections show favourable performance. Dave et al. studied the energy efficiency and QoS performance of IEEE 802.15.4 and IEEE 802.11e [11] MAC protocols under two generic applications: a wave-form real time stream and a real-time parameter measurement stream [12]. Table 5 shows the throughput and the Power (in mW) for both applications. The AC_BE and AC_VO represent the access categories voice and best-effort in the IEEE 802.11e. Since the IEEE 802.15.4 operates in the 2.4 GHz unlicensed band, the possibilities of interference from other devices such as IEEE 802.11 and microwave are inevitable. A series of experiments to evaluate the impact of IEEE 802.11 and microwave ovens on the IEEE 802.15.4 transmission are carried out in [13]. The authors considered XBee 802.15.4 development kit that has two XBee modules. Table 6 shows the affects of microwave oven on the XBee remote module. When the microwave oven is ON, the packet success rate and the standard deviation is degraded to 96.85% and 3.22% respectively. However, there is no loss when the XBee modules are taken 2 meters away from the microwave oven. 3.2.2. Heartbeat Driven MAC Protocol (H-MAC) A Heartbeat Driven MAC protocol (H-MAC) [14] is a TDMA-based protocol originally proposed for a star topology WBAN. The energy efficiency is improved by exploiting heartbeat rhythm information in order to synchronize the nodes. The nodes do not need to receive periodic information to perform synchronization. The heartbeat rhythm can be extracted from the sensory data and hence all the rhythms represented by peak sequences are naturally synchronized. The H-MAC protocol assigns dedicated time slots to each node to guarantee collision-free transmission. In addition, this protocol is supported by an active synchronization recovery scheme where two resynchronization schemes are implemented. Although H-MAC protocol reduces the extra energy cost required for synchronization, it does not support sporadic events. Since the TDMA slots are dedicated and not traffic adaptive, H-MAC protocol encounters low spectral/bandwidth efficiency in case of a low traffic. For example, a blood pressure node may not need a dedicated time slot while an endoscope pill may require a number of dedicated time slots when deployed in a WBAN. But the slots should be released when the endoscope pill is expelled. The heartbeat rhythm information varies depending on the patient condition. It may not reveal valid information for synchronization all the time. One of the solutions is to assign the time slots based on the nodes traffic information and to receive synchronization packets when required, i.e., when a node has data to transmit/receive. 3.2.3. Reservation-based Dynamic TDMA Protocol (DTDMA) A Reservation-based Dynamic TDMA Protocol (DTDMA) [15] is originally proposed for a normal (periodic) WBAN traffic where slots are allocated to the nodes which have buffered packets and are released to other nodes when the data transmission/reception is completed. The channel is bounded by superframe structures. Each superframe consists of a beacon used to carry control information including slot allocation information, a CFP period a configurable period used for data transmission, a CAP period a fixed period used for short command packets using slotted aloha protocol, and a configurable inactive period used to save energy. Unlike a beacon-enabled IEEE 802.15.4 superframe structure where the CAP duration is followed by CFP duration, in DTDMA protocol the CFP duration is followed by CAP duration in order to enable the nodes to send CFP traffic earlier than CAP traffic. In addition, the duration of inactive period is configurable based on the CFP slot duration. If there is no CFP t raffic, the inactive period will be increased. The DTDMA superframe structure is given in 2(a). It has been shown that for a normal (periodic) traffic, the DTDMA protocol provides more dependability in terms of low packet dropping rate and low energy consumption when compared with IEEE 802.15.4. However, it does not support emergency and on-demand traffic. Although the slot allocation based on the traffic information is a good approach, the DTDMA protocol has several limitations when considered for the MICS band. The MICS band has ten channels where each channel has 300 Kbps bandwidth. The DTDMA protocol is valid only for one channel and cannot operate on ten channels simultaneously. In addition, the DTDMA protocol does not support the channel allocation mechanism in the MICS band. This protocol can be further investigated for the MICS band by integrating the channel information in the beacon frame. The new concept may be called Frequency-based DTDMA (F-DTDMA), i.e., the coordinator first selects one of the channels in the MICS band and then divides the selected channel in TDMA superframe (s) according to the DTDMA protocol. However the FCC has imposed several restrictions on the channel selection/allocation mechanism in the MICS band, which further creates problems for the MAC designers. 3.2.4. BodyMAC Protocol A BodyMAC protocol is a TDMA-based protocol where the channel is bounded by TDMA superframe structures with downlink and uplink subframes as given in 2(b) [16]. The downlink frame is used to accommodate the on-demand traffic and the uplink frame is used to accommodate the normal traffic. There is no proper mechanism to handle the emergency traffic. The uplink frame is further divided into CAP and CFP periods. The CAP period is used to transmit small size MAC packets. The CFP period is used to transmit the normal data in a TDMA slot. The duration of the downlink and uplink superframes are defined by the coordinator. The advantage of the BodyMAC protocol is that it accommodates the on-demand traffic using the downlink subframe. However, in case of low-power implants (which should not receive beacons periodically), the coordinator has to wake up the implant first and then send synchronization packets. After synchronization, the coordinator can request/send data in the downlink subframe. The wake up procedure for low-power implants is not defined in the BodyMAC protocol. One of the solutions is to use a wakeup radio in order to wake up low-power implants before using the downlink subframe. In addition the wakeup packets can be used to carry control information such as channel (MICS band) and slot allocation information from the coordinator to the nodes. Finally, the BodyMAC protocol uses the CSMA/CA protocol in the CAP period which is not reliable for a WBAN. This should be replaced by slotted-ALOHA as done in DTDMA. Further details on low-power MAC protocols (originally proposed for WSNs) for a WBAN are given in Appendix I. 3.3. Case Study: IEEE 802.15.4, PB-TDMA, and SMAC Protocols for a WBAN In this section, we investigate the performance of a beacon-enabled IEEE 802.15.4, preamble-based TDMA [17], and SMAC protocols for an on-body communication system. Our analysis is verified by extensive simulations using NS-2. The wireless physical parameters are considered according to a low-power Nordic nRF2401 transceiver (Chipcon CC2420 radio [18] is considered in case of IEEE 802.15.4) [19]. This radio transceiver operates in the 2.4-2.5 GHz band with an optimum transmission power of -5dBm. We use the shadowing propagation model throughout the simulations. We consider a total of 7 nodes firmly placed on a human body. The nodes are connected to the coordinator in a star topology. The distribution of the nodes and the coordinator is given in 3(a). The initial nodes energy is 5 Joules. The packet size is 120 bytes. The average data transmission rate of ECG, EEG, and EMG is 10, 70, and 100 kbps. The transport agent is a user datagram protocol (UDP). Since the traffic is an uplink t raffic, the buffer size at the coordinator is considered unlimited. In a real WBAN, the buffer size should be configurable based on the application requirements. For energy calculation, we use the existing energy model defined in NS-2. The simulation area is 33 meter and each node generates constant bit rate (CBR) traffic. The CBR traffic is an ideal model for some of the medical applications, where the nodes send data based on pre-defined traffic patterns. However, most of the nodes in a WBAN have heterogeneous traffic characteristics and they generate periodic and aperiodic traffic. In this case, they will have many traffic models operating at the same time, ranging from CBR to variable bit rate (VBR). 3(b) shows the throughput of the IEEE 802.15.4, PB-TDMA, and S-MAC protocols. The performance of the IEEE 802.15.4, when cond in a beacon-enabled mode, outperforms PB-TDMA and S-MAC protocols. The efficiency of a MAC protocol depends on the traffic pattern. In this case, S-MAC protocol results poor performance because the traffic scenario that we generated is not an ideal scenario for the S-MAC. 3(c) shows the residual energy at various nodes during simulation time. When nodes finish their transmission, they go into sleep mode, as indicated by the horizontal line. The coordinator has a considerable energy loss because it always listens to the other nodes. However, the energy consumption of the coordinator is not a critical issue in a WBAN. We further analyze the residual energy at the ECG node for different transmission powers. There is a minor change in energy loss for three different transmission powers as given in 3(d). This concludes that reducing the transmission power only d oes not save energy unless supported by an efficient power management scheme. The IEEE 802.15.4 can be considered for certain on-body medical applications, but it does not achieve the level of power required for in-body nodes. It is not sufficient for high data rate medical and non-medical applications due to its limitations to 250 kbps. Furthermore, it uses slotted or unslotted CSMA/CA where the nodes are required to sense the channel before transmission. However, the channel sensing is not guaranteed in MICS band because the path loss inside the human body due to tissue heating is much higher than in free space. Bin et.al studied the clear channel assessment (CCA) range of in-body nodes which is only 0.5 meters [20]. This unreliability in CCA indicates that CSMA/CA is not an ideal technique for the in-body communication system. An alternative approach is to use a TDMA-based protocol that contains a beacon, a configurable contention access period (CCAP), and a contention free period (CFP) [21]. Unlike the IEEE 802.15.4, this protocol is required to use a slot ted-ALOHA protocol in the CCAP instead of CSMA/CA. The CCAP period should contain few slots (3 or 4) of equal duration and can be used for short data transmission and a guaranteed time slot (GTS) allocation. To enable a logical connection between the in-body and the on-body communication systems, a method called bridging function can be used as discussed in [21]. The bridging function can integrate in-body and on-body nodes into a WBAN, thus satisfying the MAC transparency requirement. Further details about bridging function are given in [22]. 3.4. Discussion Since the CSMA/CA is not suitable due to unreliable CCA and heavy collision problems, it can be seen that the most reliable power-efficient protocol is a TDMA-based protocol. Many protocols have been proposed for a WBAN and most of them are based on a TDMA-based mechanism. However, all of them have pros and cons for a real WBAN system that should operate on Multi-PHYs (MICS, ISM, and UWB) simultaneously. The MAC transparency has been a hot topic for the MAC designers since different bands have different characteristics in terms of data rate, number of channels in a particular frequency band, and data prioritization. A good MAC protocol should enable reliable operation on MICS, ISM, and UWB etc bands simultaneously. The main problems are related to MICS band due to FCC restrictions [23]. According to FCC, â€Å"Within 5 seconds prior to initiating a communications session, circuitry associated with a medical implant programmer/control transmitter must monitor the channel or channels the MICS system devices intend to occupy for a minimum of 10 milliseconds per channel.† In other words, the coordinator must perform Listen-before-talking (LBT) criteria prior to a MICS communication sessions. The implants are not allowed to On the Implant Communication and MAC Protocols for a WBAN On the Implant Communication and MAC Protocols for a WBAN Abstract Recent advances in micro-electro-mechanical systems (MEMS), wireless communication, low-power intelligent sensors, and semiconductor technologies have allowed the realization of a wireless body area network (WBAN). A WBAN provides unobtrusive health monitoring for a long period of time with real-time updates to the physician. It is widely used for ubiquitous healthcare, entertainment, and military applications. The implantable and wearable medical devices have several critical requirements such as power consumption, data rate, size, and low-power medium access control (MAC) protocols. This article consists of two parts: body implant communication, which is concerned with the communication to and from a human body using RF technology, and WBAN MAC protocols, which presents several low-power MAC protocols for a WBAN with useful guidelines. In body implant communication, the in-body radio frequency (RF) performance is affected considerably by the implants depth inside the human body as well as by the muscle and fat. We observe best performance at a depth of 3cm and not close to the human skin. Furthermore, the study of low-power MAC protocols highlights the most important aspects of developing a single, a low-power, and a reliable MAC protocol for a WBAN. Keywords: In-body, on-body, RF communication, Implant, WBAN 1. Introduction Cardiovascular diseases are the foremost cause of deaths in the United States and Europe since 1900. More than ten million people are affected in Europe, one million in the US, and twenty two million people in the world [1]. The number is projected to be triple by 2020, resulting in an expenditure of around 20% of the gross domestic product (GDP). The ratio is 17% in South Korea and 39% in the UK [2]. The healthcare expenditure in the US is expected to be increased from $2.9 trillion in 2009 to $4 trillion US dollars in 2015 [3]. The impending health crisis attracts researchers, industrialists, and economists towards optimal and quick health solutions. The non-intrusive and ambulatory health monitoring of patients vital signs with real time updates of medical records via internet provide economical solutions to the health care systems. A wireless body area network (WBAN) is becoming increasingly important for healthcare systems, sporting activities, and members of emergency as well as military services. WBAN is an integration of in-body (implants) and on-body (wearable) sensors that allow inexpensive, unobtrusive, and long-term health monitoring of a patient during normal daily activities for prolonged periods of time. In-body radio frequency (RF) communications have the potential to dramatically change the future of healthcare. For example, they allow an implanted pacemaker to regularly transmit performance data and the patients health status to the physician. However, the human body poses many wireless transmission challenges. This is partially conductive and consists of materials having different dielectric constants and characteristics impedance. The interface of muscles and fats may reflect the RF wave rather than transmitting it. The key elements of an RF-linked implant are the in-body antenna and the communi cation link performance. Also, in the case of many implants and wearable sensors, a low-power MAC protocol is required to accommodate the heterogeneous traffic in a power-efficient manner. This article is divided into two parts: body implant communication and WBAN MAC protocols. In the body implant communication part, we look at the RF communication link performance at various depths inside a human (artificial) body. In the MAC part, we review the existing low-power MAC protocols and discuss their pros and cons in the context of a WBAN. We further provide alternative MAC solutions for in-body and on-body communication systems. The rest of the article is divided into three sections. In section 2, we present a discussion on body implant communication including in-body electromagnetic induction, RF communication, antenna design, and the communication link performance. Section 3 discusses several low-power MAC protocols and realizes a need for a new, a low-power, and a reliable MAC protocol for a WBAN. The final section concludes our work. 2. Body Implant Communication There are several ways to communicate with an implant that includes the use of electromagnetic induction and RF technology. Both are wireless and their use depends on the application requirements. Further, the key elements of an RF-linked implant are the in-body antenna and the communication link performance. The following part discusses in-body electromagnetic induction, RF communication, antenna design, and the communication link performance. 2.1. In-body Electromagnetic Induction Several applications still use electromagnetic coupling to provide a communication link to an implant device. In this scheme, an external coil is held very close to the body that couples to a coil implanted just below the skin surface. The implant is powered by the coupled magnetic field and requires no battery for communication. Data is transferred from the implant by altering the impedance of the implanted loop that is detected by the external coil and electronics. This type of communication is commonly used to identify animals that have been injected with an electronic tag. Electromagnetic induction is used when continuous, long-term communication is required. The base band for electromagnetic communication is typically 13.56 MHz or 28 MHz, with other frequencies also available. The choice of a particular band is subject to regulation for maximum specific absorption rate (SAR). The inductive coupling achieves best power transfer efficiency when uses large transmit and receive coil s. It, however, becomes less efficient when the space is an issue of the device is implanted deep inside the human body. Furthermore, inductive coupling technique does not support a very high data rate and cannot initiate a communication session from inside of the body. 2.2. In-body RF Communication Compared with the electromagnetic induction, RF communication dramatically increases bandwidth and supports a two-way data communication. The band designated for the in-body RF communication is medical implant communication service (MICS) band and is around 403 to 405 MHz. This band has a power limit of 25  µW in the air and is usually split into ten channels of 300 kHz bandwidth each. The human body is a medium that poses numerous wireless transmission challenges. It consists of various components that are not predictable and will change as the patient ages, gains or losses weight, or even changes posture. Values of dielectric constant (ÃŽ µr), conductivity (ÏÆ') and characteristic impedance (Zo) for some body tissue are given in table 1 [4]. This demonstrates that these two tissue types are very different. Also, the dielectric constant affects the wavelength of a signal. At 403 MHz, the wavelength in the air is 744mm, but in muscle with ÃŽ µr = 50 the wavelength reduces to 105mm, which helps in designing implanted antennas. 2.3. In-body Antenna Design A modern in-body antenna should be tuneable by using an intelligent transceiver and software routine. This enables the antenna coupling circuit to be optimised. Due to the frequency, and available volume, a non-resonant antenna is commonly used. It has a lower gain than a resonant antenna. This makes design of the antenna coupling circuit very important. Antenna options are dictated by the location of the implant. A patch antenna can be used when the implant is flat. Patch antennas are comprised of a flat insulating substrate coated on both sides with a conductor. The substrate is a body compatible material with a platinum or a platinum/iridium conductor. The upper surface is the active face and is connected to the transceiver. The connection to the transceiver needs to pass through the case where the hermetic seal is maintained, requiring a feed-through. The feed-through must have no filter capacitors present; these are common on other devices. An implanted patch antenna is electrically larger than its physical size because it is immersed in a high (ÃŽ µr) medium. It can be much larger electrically if the substrate is of higher (ÃŽ µr), such as titania or zirconia. A loop antenna can also be attached to the implant. This antenna operates mostly by the magnetic field, whereas the patch operates mostly by the electric field. The loop antenna delivers performance comparable to that of a dipole, but with a considerably smaller size. In addition, the magnetic permeability of muscle or fat is very similar to that of an air, unlike the dielectric constant that varies considerably. This property enables an antenna to be built and used with much less need for retuning. A loop antenna can be mounted on the case in a biocompatible structure. 2.4. In-body Link Performance The demonstration system consists of a base-station, an implant, antennas, and a controlling laptop. The base-station contains a printed circuit board (PCB) with a wakeup RF circuit, a Zarlink ZL70101 IC, and a micro-controller. It sends a wakeup signal on industrial, scientific, and medical (ISM) 2.4 GHz band to power up the implant to communicate. It also supports communication within the MICS band. The implant contains a Zarlink ZL70101 IC, a micro-controller, and a battery. The power limits of the wakeup signal for ISM and MICS bands transmitters are 100mW and 25  µW respectively. Experiments that measure the performance of an implant inside a living body are difficult to arrange. The alternative is to use 3D simulation software or a body phantom defined in [5]. The use of 3D simulation software is time consuming and hence practically not valuable. Therefore, measurements are generally performed using the body phantom and immersing a battery-powered implant into it [6]. Since no additional cables are attached to the test implant, the interference errors in the measurements are minimal. The body phantom is filled with a liquid that mimics the electrical properties of the human body tissues. The test environment is an anechoic chamber that includes a screened room. The interior walls of the room have sound-absorbent cones to minimize any reflections from walls or the floor that could distort the results. In real life, however, the results will be affected by the reflections from walls, desks, and other equipment and hardware. The body phantom is mounted on a woo den stand (non-conductive). The distance from the body phantom to the base-station is 3m. The MICS base-station dipole antenna is mounted on a stand. 1(a) shows the anechoic chamber with a body phantom (on the wooden stand), a log periodic test antenna (foreground), and a base-station dipole (right). The log periodic antenna is used to calculate the power radiated from the body phantom. A depth is defined as the horizontal distance between the outer skin of the phantom and the test implant. Vertical polarization of the implant is the case when the long side of the box and the patch antenna is vertical. The link performance is measured once the communication link is established. The measurements include the effective radiated power (ERP) from the implant, the received signal at the implant from the base-station, and the link quality. Measurements are made over a set distance with all the combinations of implant and test antenna polarisations, i.e., vertical-vertical (V-V), horizontal-vertical (H-V), vertical-horizontal (V-H), and horizontal-horizontal (H-H) polarisations. Typical results are shown in 1(b) where the ERP is calculated from the received signal power and the antenna characteristics. The measurement of the signal levels is done with the log periodic antenna and the spectrum analyzer. It can be seen in the that there is a significant difference in signal levels with polarisation combinations and depths. For a V-V polarisation, the ERP increases from a 1cm depth to a maximum between 2 and 7 cm, and then it decreases. The gradual increase is due to the simulated body acti ng as a parasitic antenna. The also shows how the signal level is affected by the depth with different polarisation. Such a test needs to be done with the antenna that is to be used in the final product. To measure the received signal at the implant, the Zarlink ZL70101 has an inbuilt receive signal strength indication (RSSI) function that gives a measure of the signal level detected. RSSI is a relative measurement with no calibration. The implant receives and measures a continuous wave signal transmitted by the base-station. In this case, the implant and the base-station antennas are vertically polarised. 1(c) shows an increase in the signal level at a depth between 3 and 4cm for a 15dec power. The power settings refer to the base-station and are cond to set the ERP to 25  µW. Signal levels are not valuable unless they are related to data transmission. One way to maintain the link quality is to measure the number of times the error correction is invoked during the transmission of 100 blocks of data. Two types of error correction codes, i.e., error correction code (ECC) and cyclic redundancy code (CRC) are invoked to maintain data integrity and reliability. The fewer ECC and CRC invocations result in better link quality. In 1(d), the error correction is lowest at a depth between 3 and 5 cm. A sample of ECC data collected at a 3cm implant depth is given in Table 2. The Count indicates the number of data blocks, the Time (ms) indicates the block transmission time, and the ECC indicates the number of times it is invoked. During the transmission of 100 blocks of data at a 3cm depth, the ECC is invoked 368 times, which is further equivalent to an average 3.68 times (as given in 1(d)). 2.5. Discussion The ERP, RSSI, as well as the ECC and CRC plots show that the implant demonstrates the best performance at a depth between 3 and 5 cm. The depth and position of an implant is not chosen for engineering performance but for the best clinical reasons. The implant designer must be aware of the possible losses through the human body. The attenuation and the parasitic antenna effects vary from patient to patient, with the position of the implant and with the time as the patient gains, or looses weight. Therefore, these factors need to be built into the link budget. 3. WBAN MAC Protocols Some of the common objectives in a WBAN are to achieve maximum throughput, minimum delay, and to maximize the network lifetime by controlling the main sources of energy waste, i.e., collision, idle listening, overhearing, and control packet overhead. A collision occurs when more than one packet transmits data at the same time. The collided packets have to be retransmitted, which consumes extra energy. The second source of energy waste is idle listening, meaning that a node listens to an idle channel to receive data. The third source is overhearing, i.e., to receive packets that are destined to other nodes. The last source is control packet overhead, meaning that control information area added to the payload. Minimal number of control packets should be used for data transmission. Generally MAC protocols are grouped into contention-based and schedule-based MAC protocols. In contention-based MAC protocols such as carrier sense multiple access/collision avoidance (CSMA/CA) protocols, nodes contend for the channel to transmit data. If the channel is busy, the node defers its transmission until it becomes idle. These protocols are scalable with no strict time synchronization constraint. However, they incur significant protocol overhead. In schedule-based protocols such as time division multiple access (TDMA) protocols, the channel is divided into time slots of fixed or variable duration. These slots are assigned to nodes and each node transmits during its slot period. These protocols are energy conserving protocols. Since the duty cycle of radio is reduced, there is no contention, idle listening and overhearing problems. But these protocols require frequent synchronization. Table 3 compares CSMA/CA and TDMA protocols. 3.1. WBAN MAC Requirements The most important attribute of a good MAC protocol for a WBAN is energy efficiency. In some applications, the device should support a battery life of months or years without interventions, while others may require a battery life of tens of hours due to the nature of the applications. For example, cardiac defibrillators and pacemakers should have a lifetime of more than 5 years, while swallowable camera pills have a lifetime of 12 hours. Power-efficient and flexible duty cycling techniques are required to minimize the idle listening, overhearing, packet collisions and control packet overhead. Furthermore, low duty cycle nodes should not receive frequent synchronization and control information (beacon frames) if they have no data to send or receive. The WBAN MAC should also support simultaneous operation on in-body (MICS) and on-body channels (ISM or UWB) at the same time. In other words, it should support multiple physical layer (Multi-PHYs) communication or MAC transparency. Other important factors are scalability and adaptability to changes in the network, delay, throughput, and bandwidth utilization. Changes in the network topology, the position of the human body, and the node density should be handled rapidly and successfully. The MAC protocol for a WBAN should consider the electrical properties of the human body and the diverse traffic nature of in-body and on-body nodes. For example, the data rate of in-body nodes varies, ranging from few kbps in pacemaker to several Mbps in capsular endoscope. In the following sections, we discuss proposed MAC protocols for a WBAN with useful guidelines. We also present a case study of IEEE 802.15.4, PB-TDMA, and S-MAC protocols for a WBAN using NS2 simulator. 3.2. Proposed MAC Protocols for a WBAN In this section, we study proposed MAC protocols for a WBAN followed by useful suggestions/comments. Many of the proposed MAC protocols are the extension of existing MAC protocols originally proposed for wireless sensor networks (WSNs). 3.2.1. IEEE 802.15.4 IEEE 802.15.4 has remained the main focus of many researchers during the past few years. Some of the main reasons of selecting IEEE 802.15.4 for a WBAN were low-power communication and support of low data rate WBAN applications. Nicolas et.al investigated the performance of a non-beacon IEEE 802.15.4 in [7], where low upload/download rates (mostly per hour) are considered. They concluded that the non-beacon IEEE 802.15.4 results in 10 to 15 years sensor lifetime for low data rate and asymmetric WBAN traffic. However, their work considers data transmission on the basis of periodic intervals which is not a perfect scenario in a real WBAN. Furthermore, the data rate of in-body and on-body nodes are not always low, i.e., it ranges from 10 Kbps to 10 Mbps, and hence reduces the lifetime of the sensor nodes. Li et.al studied the behavior of slotted and unslotted CSMA/CA mechanisms and concluded that the unslotted mechanism performs better than the slotted one in terms of throughput and lat ency but with high cost of power consumption [8]. Intel Corporation conducted a series of experiments to analyze the performance of IEEE 802.15.4 for a WBAN [9]. They deployed a number of Intel Mote 2 [10] nodes on chest, waist, and the right ankle. Table 4 shows the throughput at a 0dBm transmit power when a person is standing and sitting on a chair. The connection between ankle and waist cannot be established, even for a short distance of 1.5m. All other connections show favourable performance. Dave et al. studied the energy efficiency and QoS performance of IEEE 802.15.4 and IEEE 802.11e [11] MAC protocols under two generic applications: a wave-form real time stream and a real-time parameter measurement stream [12]. Table 5 shows the throughput and the Power (in mW) for both applications. The AC_BE and AC_VO represent the access categories voice and best-effort in the IEEE 802.11e. Since the IEEE 802.15.4 operates in the 2.4 GHz unlicensed band, the possibilities of interference from other devices such as IEEE 802.11 and microwave are inevitable. A series of experiments to evaluate the impact of IEEE 802.11 and microwave ovens on the IEEE 802.15.4 transmission are carried out in [13]. The authors considered XBee 802.15.4 development kit that has two XBee modules. Table 6 shows the affects of microwave oven on the XBee remote module. When the microwave oven is ON, the packet success rate and the standard deviation is degraded to 96.85% and 3.22% respectively. However, there is no loss when the XBee modules are taken 2 meters away from the microwave oven. 3.2.2. Heartbeat Driven MAC Protocol (H-MAC) A Heartbeat Driven MAC protocol (H-MAC) [14] is a TDMA-based protocol originally proposed for a star topology WBAN. The energy efficiency is improved by exploiting heartbeat rhythm information in order to synchronize the nodes. The nodes do not need to receive periodic information to perform synchronization. The heartbeat rhythm can be extracted from the sensory data and hence all the rhythms represented by peak sequences are naturally synchronized. The H-MAC protocol assigns dedicated time slots to each node to guarantee collision-free transmission. In addition, this protocol is supported by an active synchronization recovery scheme where two resynchronization schemes are implemented. Although H-MAC protocol reduces the extra energy cost required for synchronization, it does not support sporadic events. Since the TDMA slots are dedicated and not traffic adaptive, H-MAC protocol encounters low spectral/bandwidth efficiency in case of a low traffic. For example, a blood pressure node may not need a dedicated time slot while an endoscope pill may require a number of dedicated time slots when deployed in a WBAN. But the slots should be released when the endoscope pill is expelled. The heartbeat rhythm information varies depending on the patient condition. It may not reveal valid information for synchronization all the time. One of the solutions is to assign the time slots based on the nodes traffic information and to receive synchronization packets when required, i.e., when a node has data to transmit/receive. 3.2.3. Reservation-based Dynamic TDMA Protocol (DTDMA) A Reservation-based Dynamic TDMA Protocol (DTDMA) [15] is originally proposed for a normal (periodic) WBAN traffic where slots are allocated to the nodes which have buffered packets and are released to other nodes when the data transmission/reception is completed. The channel is bounded by superframe structures. Each superframe consists of a beacon used to carry control information including slot allocation information, a CFP period a configurable period used for data transmission, a CAP period a fixed period used for short command packets using slotted aloha protocol, and a configurable inactive period used to save energy. Unlike a beacon-enabled IEEE 802.15.4 superframe structure where the CAP duration is followed by CFP duration, in DTDMA protocol the CFP duration is followed by CAP duration in order to enable the nodes to send CFP traffic earlier than CAP traffic. In addition, the duration of inactive period is configurable based on the CFP slot duration. If there is no CFP t raffic, the inactive period will be increased. The DTDMA superframe structure is given in 2(a). It has been shown that for a normal (periodic) traffic, the DTDMA protocol provides more dependability in terms of low packet dropping rate and low energy consumption when compared with IEEE 802.15.4. However, it does not support emergency and on-demand traffic. Although the slot allocation based on the traffic information is a good approach, the DTDMA protocol has several limitations when considered for the MICS band. The MICS band has ten channels where each channel has 300 Kbps bandwidth. The DTDMA protocol is valid only for one channel and cannot operate on ten channels simultaneously. In addition, the DTDMA protocol does not support the channel allocation mechanism in the MICS band. This protocol can be further investigated for the MICS band by integrating the channel information in the beacon frame. The new concept may be called Frequency-based DTDMA (F-DTDMA), i.e., the coordinator first selects one of the channels in the MICS band and then divides the selected channel in TDMA superframe (s) according to the DTDMA protocol. However the FCC has imposed several restrictions on the channel selection/allocation mechanism in the MICS band, which further creates problems for the MAC designers. 3.2.4. BodyMAC Protocol A BodyMAC protocol is a TDMA-based protocol where the channel is bounded by TDMA superframe structures with downlink and uplink subframes as given in 2(b) [16]. The downlink frame is used to accommodate the on-demand traffic and the uplink frame is used to accommodate the normal traffic. There is no proper mechanism to handle the emergency traffic. The uplink frame is further divided into CAP and CFP periods. The CAP period is used to transmit small size MAC packets. The CFP period is used to transmit the normal data in a TDMA slot. The duration of the downlink and uplink superframes are defined by the coordinator. The advantage of the BodyMAC protocol is that it accommodates the on-demand traffic using the downlink subframe. However, in case of low-power implants (which should not receive beacons periodically), the coordinator has to wake up the implant first and then send synchronization packets. After synchronization, the coordinator can request/send data in the downlink subframe. The wake up procedure for low-power implants is not defined in the BodyMAC protocol. One of the solutions is to use a wakeup radio in order to wake up low-power implants before using the downlink subframe. In addition the wakeup packets can be used to carry control information such as channel (MICS band) and slot allocation information from the coordinator to the nodes. Finally, the BodyMAC protocol uses the CSMA/CA protocol in the CAP period which is not reliable for a WBAN. This should be replaced by slotted-ALOHA as done in DTDMA. Further details on low-power MAC protocols (originally proposed for WSNs) for a WBAN are given in Appendix I. 3.3. Case Study: IEEE 802.15.4, PB-TDMA, and SMAC Protocols for a WBAN In this section, we investigate the performance of a beacon-enabled IEEE 802.15.4, preamble-based TDMA [17], and SMAC protocols for an on-body communication system. Our analysis is verified by extensive simulations using NS-2. The wireless physical parameters are considered according to a low-power Nordic nRF2401 transceiver (Chipcon CC2420 radio [18] is considered in case of IEEE 802.15.4) [19]. This radio transceiver operates in the 2.4-2.5 GHz band with an optimum transmission power of -5dBm. We use the shadowing propagation model throughout the simulations. We consider a total of 7 nodes firmly placed on a human body. The nodes are connected to the coordinator in a star topology. The distribution of the nodes and the coordinator is given in 3(a). The initial nodes energy is 5 Joules. The packet size is 120 bytes. The average data transmission rate of ECG, EEG, and EMG is 10, 70, and 100 kbps. The transport agent is a user datagram protocol (UDP). Since the traffic is an uplink t raffic, the buffer size at the coordinator is considered unlimited. In a real WBAN, the buffer size should be configurable based on the application requirements. For energy calculation, we use the existing energy model defined in NS-2. The simulation area is 33 meter and each node generates constant bit rate (CBR) traffic. The CBR traffic is an ideal model for some of the medical applications, where the nodes send data based on pre-defined traffic patterns. However, most of the nodes in a WBAN have heterogeneous traffic characteristics and they generate periodic and aperiodic traffic. In this case, they will have many traffic models operating at the same time, ranging from CBR to variable bit rate (VBR). 3(b) shows the throughput of the IEEE 802.15.4, PB-TDMA, and S-MAC protocols. The performance of the IEEE 802.15.4, when cond in a beacon-enabled mode, outperforms PB-TDMA and S-MAC protocols. The efficiency of a MAC protocol depends on the traffic pattern. In this case, S-MAC protocol results poor performance because the traffic scenario that we generated is not an ideal scenario for the S-MAC. 3(c) shows the residual energy at various nodes during simulation time. When nodes finish their transmission, they go into sleep mode, as indicated by the horizontal line. The coordinator has a considerable energy loss because it always listens to the other nodes. However, the energy consumption of the coordinator is not a critical issue in a WBAN. We further analyze the residual energy at the ECG node for different transmission powers. There is a minor change in energy loss for three different transmission powers as given in 3(d). This concludes that reducing the transmission power only d oes not save energy unless supported by an efficient power management scheme. The IEEE 802.15.4 can be considered for certain on-body medical applications, but it does not achieve the level of power required for in-body nodes. It is not sufficient for high data rate medical and non-medical applications due to its limitations to 250 kbps. Furthermore, it uses slotted or unslotted CSMA/CA where the nodes are required to sense the channel before transmission. However, the channel sensing is not guaranteed in MICS band because the path loss inside the human body due to tissue heating is much higher than in free space. Bin et.al studied the clear channel assessment (CCA) range of in-body nodes which is only 0.5 meters [20]. This unreliability in CCA indicates that CSMA/CA is not an ideal technique for the in-body communication system. An alternative approach is to use a TDMA-based protocol that contains a beacon, a configurable contention access period (CCAP), and a contention free period (CFP) [21]. Unlike the IEEE 802.15.4, this protocol is required to use a slot ted-ALOHA protocol in the CCAP instead of CSMA/CA. The CCAP period should contain few slots (3 or 4) of equal duration and can be used for short data transmission and a guaranteed time slot (GTS) allocation. To enable a logical connection between the in-body and the on-body communication systems, a method called bridging function can be used as discussed in [21]. The bridging function can integrate in-body and on-body nodes into a WBAN, thus satisfying the MAC transparency requirement. Further details about bridging function are given in [22]. 3.4. Discussion Since the CSMA/CA is not suitable due to unreliable CCA and heavy collision problems, it can be seen that the most reliable power-efficient protocol is a TDMA-based protocol. Many protocols have been proposed for a WBAN and most of them are based on a TDMA-based mechanism. However, all of them have pros and cons for a real WBAN system that should operate on Multi-PHYs (MICS, ISM, and UWB) simultaneously. The MAC transparency has been a hot topic for the MAC designers since different bands have different characteristics in terms of data rate, number of channels in a particular frequency band, and data prioritization. A good MAC protocol should enable reliable operation on MICS, ISM, and UWB etc bands simultaneously. The main problems are related to MICS band due to FCC restrictions [23]. According to FCC, â€Å"Within 5 seconds prior to initiating a communications session, circuitry associated with a medical implant programmer/control transmitter must monitor the channel or channels the MICS system devices intend to occupy for a minimum of 10 milliseconds per channel.† In other words, the coordinator must perform Listen-before-talking (LBT) criteria prior to a MICS communication sessions. The implants are not allowed to

Depression and Psychosis Essay -- Mental Health

For the purpose of this essay the user group I have decided to focus upon is people who suffer from mental health issues, in particular depression and psychosis. I will firstly talk about the illness and about the client group concerned. I will then discuss different treatments available and how effective communication is essential for the well being of these clients. I will then focus on different theories of communication from a psychology perspective and conclusively will discuss and critically analysis powers imbalances, inequalities and disadvantages. Depression haunts the lives of many. It exists in many forms, takes various guises and has been recognised for many centuries. Over two thousand years ago the Greek physician Hippocrates labelled the illness melancholia. The early thinking surrounding depression especially within the Greek community believed that "depression arouse of the body humour especially black bile." (Gilbert 1994) Early reports of depression can be found in numerous biblical texts. King soleman is believed to have suffered from an evil spirit and dark moods from which he eventually killed himself. " The book of Job is regarded as the work of a depressive." (S.Mangen 82) More recent sufferers include politicians such as Winston Churchill and Abraham Lincon and various other writers and poets such as Thomas Mann and Edgar Allen Poe. So whatever else we may say about depression, it seems that it has been in existence for a very long time. It is not unique to humans and various animal models of depression ha ve been advanced and researched. The type of people who suffer from depression vary and it is not too be stereotyped to the image of a person contained within a mental hospital rocking back... ...eds to be shown at all times and the lead should always be taken from the client. Due to word restrictions within this essay I feel that it is now important to bring together and conclude my findings regarding effective communication and depression. The example of my experience with the psychiatrist was a worse case scenario of communication gone wrong and basically everything that he did needs to be reversed for successful communication to take place. Needless to say when I felt better and was going through an "stable" period I demanded a change of psychiatrist and have since embarked on a university degree. Good communication skills can not however be read about or taught they are something that is practically learnt and the only way in which to monitor them is by being self analysing at all times and receiving feedback from clients and friends.

An analysis of Information Security Governance in the Universities in Zimbabwe Essay

Abstract The complexity and criticality of information security and its governance demand that it be elevated to the highest organizational levels. Within a university setup, information assets include student and personnel records, health and financial information, research data, teaching and learning materials and all restricted and unrestricted electronic library materials. Security of these information assets is among the highest priorities in terms of risk and liabilities, business continuity, and protection of university reputations. As a critical resource, information must be treated like any other asset essential to the survival and success of the organization. In this paper the writer is going to discuss the need for implementing Information Security Governance within institutions of higher education. Further than that, a discussion on how to best practice Information Security governance within the universities in Zimbabwe followed by an assessment on how far the Zimbabwean universities have implemented Information Security Governance. A combination of questionnaires and interviews is going to be used as a tool to gather data and some recommendations are stated towards the end of the paper. Introduction Governance, as defined by the IT Governance Institute (2003), is the â€Å"set of responsibilities and practices exercised by the board and executive management with the goal of providing strategic direction, ensuring that objectives are achieved, ascertaining that risks are managed appropriately and verifying that the enterprise’s resources are used responsibly.† Information security governance is the system by which an organization directs and controls information security (adapted from ISO 38500). It specifies the accountability framework and provides oversight to ensure that risks are adequately mitigated as well as ensuring that security strategies are aligned with business and consistent with regulations. To exercise effective enterprise and information security governance, boards and senior executives must have a clear understanding of what to expect from their enterprise’s information security programme. They need to know how to direct  the implementation of an information security programme, how to evaluate their own status with regard to an existing security programme and how to decide the strategy and objectives of an effective security programme (IT Governance Institute, 2006). Stakeholders are becoming more and more concerned about the information security as news of hacking, data theft and other attacks happen more frequently than ever dreamt of. Executive management has been showered with the responsibility of ensuring an organization provides users with secure information systems environment. Information security is not only a technical issue, but a business and governance challenge that involves adequate risk management, reporting and accountability. Effective security requires the active involvement of executives to assess emerging threats and the organization’s response to them (Corporate Governance Task Force, 2004). Furthermore the organizations need to protect themselves against the risks inherent in the use of information systems while simultaneously recognizing the benefits that can accrue from having secure information systems. Peter Drucker (1993) stated: â€Å"The diffusion of technology and the commodification of information transforms the role of information into a resource equal in importance to the traditionally important resources of land, labor and capital.† Thus as dependence on information system increases, the criticality of information security brings with it the need for effective information security governance. Need for Information Security Governance within universities. A key goal of information security is to reduce adverse impacts on the organization to an acceptable level of risk. Information security protects information assets against the risk of loss, operational discontinuity, misuse, unauthorized disclosure, inaccessibility and damage. It also protects against the ever-increasing potential for civil or legal liability that organizations face as a result of information inaccuracy and loss, or the absence of due care in its protection. Information security covers all information processes, physical and electronic, regardless whether they involve people and technology or relationships with trading partners, customers and third parties. Information security addresses information protection, confidentiality, availability and integrity throughout the life cycle of the information and its use within the organization. John P. Pironti (2006) suggested that among many reasons for information security  governance, the most important one is the one concerned with the legal liability, protection of the organization’s reputation and regulatory compliance. With the university setup, all members of the university community are obligated to respect and, in many cases, to protect confidential data. Medical records, student records, certain employment-related records, library use records, attorney-client communications, and certain research and other intellectual property-related records are, subject to limited exceptions, confidential as a matter of law. Many other categories of records, including faculty and other personnel records, and records relating to the university’s business and finances are, as a matter of university policy, treated as confidential. Systems (hardware and software) designed primarily to store confidential records (such as the Financial Information System and Student Information System and all medical records systems) require enhanced security protections and are controlled (strategic) systems to which access is closely monitored. Networks provide connection to records, information, and other networks and also require security protections. The use of university information technology assets in other than a manner and for the purpose of which they were intended represents a misallocation of resources and, possibly, a violation of law. To achieve all this in today’s complex, interconnected world, information security must be addressed at the highest levels of the organization, not regarded as a technical specialty relegated to the IT department. Information security is a top-down process requiring a comprehensive security strategy that is explicitly linked to the organization’s business processes and strategy. Security must address entire organization’s processes, both physical and technical, from end to end. Hence, Information security governance requires senior management commitment, a security-aware culture, promotion of good security practices and compliance with policy. It is easier to buy a solution than to change a culture, but even the most secure system will not achieve a significant degree of security if used by ill-informed, untrained, careless or indifferent personnel (IT Governance Institute, 2006). In an interview the executive director and information security expert on IT Governance and cyber security with the IT Governance and Cyber Security Institute of sub-Saharan Africa, Dr Richard Gwashy Young has this to say â€Å"†¦remember in  Zimbabwe security is regarded as an expense not an investment† (Rutsito, 2012). Benefits of Information Security Governance Good information security governance generates significant benefits, including: The Board of directors taking full responsibility for Information security initiatives Increased predictability and reduced uncertainty of business operations by lowering information security-related risks to definable and acceptable levels Protection from the increasing potential for civil or legal liability as a result of information inaccuracy or the absence of due care. The structure and framework to optimize allocation of limited security resources Assurance of effective information security policy and policy compliance A firm foundation for efficient and effective risk management, process improvement, and rapid incident response related to securing information A level of assurance that critical decisions are not based on faulty information Accountability for safeguarding information during critical business activities. Compliances with local and international regulations will be easier Improved resource management, optimizing knowledge, information security and information technology infrastructure The benefits add significant value to the organization by: Improving trust in customer/client relationships Protecting the organization’s reputation Decreasing likelihood of violations of privacy Providing greater confidence when interacting with trading partners Enabling new and better ways to process electronic transactions like publishing results online and online registration. Reducing operational costs by providing predictable outcomes—mitigating risk factors that may interrupt the process The benefits of good information security are not just a reduction in risk or a reduction in the impact should something go wrong. Good security can improve reputation, confidence and trust from others with whom business is conducted, and can even improve efficiency by avoiding wasted time and effort recovering from a security incident (IT Governance Institute, 2004). Information Security Governance Outcomes Five basic outcomes can be expected to result from developing an effective governance approach to information security: Strategic alignment of information security with institutional objectives Reduction of risk and potential business impacts to an acceptable level Value delivery through the optimization of security investments with institutional objectives Efficient utilization of security investments supporting organization objectives Performance measurement and monitoring to ensure that objectives are met Best practices The National Association of Corporate Directors (2001), recognizes the importance of information security and recommends four essential practices for boards of directors. The four practices, which are based on the practicalities of how boards operate, are: Place information security on the board’s agenda. Identify information security leaders, hold them accountable and ensure support for them. Ensure the effectiveness of the corporation’s information security policy through review and approval. Assign information security to a key committee and ensure adequate support for that committee. It is critical that management ensure that adequate resources are allocated to support the overall enterprise information security strategy (IT Governance Institute, 2006). To achieve effective information security governance, management must establish and maintain a framework to guide the development and maintenance of a comprehensive information security programme. According to Horton, et al (2000), an information security governance framework generally consists of: An information security risk management methodology; A comprehensive security strategy explicitly linked with business and IT objectives; An effective security organizational structure; A security strategy that talks about the value of information both protected and delivered; Security policies that address each aspect of strategy, control and regulation; A complete set of security standards for each policy to ensure that procedures and guidelines comply with policy; Institutionalized monitoring processes to ensure compliance and provide feedback on effectiveness and mitigation of risk; A process to ensure  continued evaluation and update of security policies, standards, procedures and risks. This kind of framework, in turn, provides the basis for the development of a cost-effective information security program me that supports an organization’s goals and provides an acceptable level of predictability for operations by limiting the impacts of adverse events. In his article Kaitano (2010), pointed some characteristics of good corporate governance coupled with good security governance. These include and not limited to: Information security being treated as and organization wide issue and leaders are accountable. Leads to viable Governance, Risk and Compliance(GRC) Milestones It is risk-based and focuses on all aspects of security Proper frameworks and programs have been implemented It is not treated as a cost but a way of doing business Roles, responsibilities and segregation of duties are defined It is addressed and enforced by policy Adequate resources are committed and Staff are aware and trained It is planned, managed, measurable and measured It is reviewed and audited The overall objective of the programme is to provide assurance that information assets are protected in accordance with their value or the risk their compromise poses to an organization. The framework generates a set of activities that supports fulfillment of this objective. Principles for information security within the University In their article titled Information Security Policy: Best Practice Document, Hostland et al (2010) pointed out some guiding principles for information security within a university setup. The following are some of the principles they mentioned: 1. Risk assessment and management The university’s approach to security should be based on risk assessments and should be continuously done and the need for protective measures evaluated. Measures must be evaluated based on the university’s role as an establishment for education and research and with regards to efficiency, cost and practical feasibility. An overall risk assessment of the  information systems should be performed annually. Risk assessments must identify, quantify and prioritize the risks according to relevant criteria for acceptable risks. Risk assessments should be carried out when implementing changes impacting information security. Some recognized methods of assessing risks like ISO/IEC 27005 should be employed. Risk management is to be carried out according to criteria approved by the management at University. Risk assessments must be approved by the management and if a risk assessment reveals unacceptable risks, measures must be implemented to reduce the risk to an acceptable level. 2. Information security policy The Vice Chancellor should ensure that the information security policy, as well as guidelines and standards, are utilized and acted upon. He must also ensure the availability of sufficient training and information material for all users, in order to enable the users to protect the university’s data and information systems. The security policy should be reviewed and updated annually or when necessary, in accordance with principles described in ISO/IEC 27001. However, all important changes to university’s activities, and other external changes related to the threat level, should result in a revision of the policy and the guidelines relevant to the information security. 3. Security organization The Vice Chancellor is responsible for all government contact. The university should appoint CSO (Chief Security Officer). Each department and section should also be responsible for implementing the unit’s information security. The managers of each unit must appoint separate security administrators. The Registrar Academics has the primary responsibility for the information security in connection with the student registry and other student related information. The IT Director has executive responsibility for information security in connection with IT systems and infrastructure. The Operations manager has executive responsibility for information security in connection with structural infrastructure. He also has overall responsibility for quality work, while the operational responsibility is delegated according to the management structure. The Registrar Human Resources also has executive responsibility for information security according to the Personal Data Act and is the controller on a daily basis of the personal information of the  employees. The Registrar Academics and Research Administration have also executive responsibility for research related personal information. University’s information security should be revised on a regular basis, through internal control and at need, with assistance from an external IT auditor. 4. Information security in connection with users of University’s services Prior to employment security responsibility and roles for employees and contractors should be described. A background check is should also be carried out of all appointees to positions at the university according to relevant laws and regulations. A confidentiality agreement should be signed by employees, contractors or others who may gain access to sensitive and/or internal information. IT regulations should be accepted for all employment contracts and for system access for third parties. During employment, the IT regulations for the university’s information security requirements should be in place and the users’ responsibility for complying with these regulations is to be emphasized. The IT regulations should be reviewed regularly with all users and with all new hires. All employees and third party users should receive adequate training and updating regarding the Information security policy and procedures. Breaches of the Information security policy and accompanying guidelines will normally result in sanctions. University’s information, information systems and other assets should only be utilized for their intended purpose. Necessary private usage is permitted. Private IT equipment in the university’s infrastructure may only be connected where explicitly permitted. All other use must be approved in advance by the IT department. On termination or change of employment, the responsibility for termination or change of employment should be clearly defined in a separate routine with relevant circulation forms. The university’s assets should be handed in at the conclusion of the need for the use of these assets. University should change or terminate access rights at termination or change of employment. A routine should be present for handling alumni relationships. Notification on employment termination or change should be carried out through the procedures defined in the personnel system. 5. Information security regarding physical conditions IT equipment and information that require protection should be placed in secure physical areas. Secure areas should have suitable access control to  ensure that only authorized personnel have access. All of the University’s buildings should be secured according to their classification by using adequate security systems, including suitable tracking/logging. Security managers for the various areas of responsibility should ensure that work performed by third parties in secure zones is suitably monitored and documented. All external doors and windows must be closed and locked at the end of the work day. On securing equipment, IT equipment which is very essential for daily activities must be protected against environmental threats (fires, flooding, temperature variations). Information classified as â€Å"sensitive† must not be stored on portable computer equipment (e.g. laptops, cell phones, memory sticks). If it is necessary to store this information on portable equipment, the information must be password protected and encrypted in compliance with guidelines from the IT department. During travel, portable computer equipment should be treated as carry-on luggage. Fire drills should also be carried out on a regular basis. 6. IT communications and operations management Purchase and installation of IT equipment and software for IT equipment must be approved by the IT department. The IT department should ensure documentation of the IT systems according to university’s standards. Changes in IT systems should only be implemented if well-founded from a business and security standpoint. The IT department should have emergency procedures in order to minimize the effect of unsuccessful changes to the IT systems. Operational procedures should be documented and the documentation must be updated following all substantial changes. Before a new IT system is put in production, plans and risk assessments should be in place to avoid errors. Additionally, routines for monitoring and managing unforeseen problems should be in place. Duties and responsibilities should be separated in a manner reducing the possibility of unauthorized or unforeseen abuse of the university’s assets. Development, testing and maintenance should be separated from operations in order to reduce the risk of unauthorized access or changes, and in order to reduce the risk of error conditions. On system planning and acceptance, the requirements for information security must be taken into consideration when designing, testing, implementing and upgrading IT systems, as well as during system changes. Routines must be developed for  change management and system development/maintenance. IT systems must be dimensioned according to capacity requirements and the load should be monitored in order to apply upgrades and adjustments in a timely manner as it is especially important for business-critical systems. Written guidelines for access control and passwords based on business and security requirements should be in place. Guidelines should be re-evaluated on a regular basis and should contain password requirements (frequency of change, minimum length, character types which may/must be utilized) and regulate password storage. All users accessing systems must be authenticated according to guidelines and should have unique combinations of usernames and passwords. Users are responsible for any usage of their usernames and passwords. Data Gathering A structured questionnaire adapted and modified from previous questionnaires used by Corporate Governance Task Force, (2004) was used as the main instrument to gather data. Of the total 13 universities in Zimbabwe, 9 managed to participate in this research. The questionnaires were completed by the Executive Dean, IT Director, Operations Manager or Chairperson for the department. Section I: Organizational Reliance on IT The first section was designed to help in determining the institution’s reliance on information technology for business continuity. Table 1: Characteristics of Organization Questions Scores/Frequency 0 1 2 3 4 Dependence on information technology systems and the Internet to conduct academic, research, and outreach programs and offer support services 9 Value of organization’s intellectual property stored or transmitted in electronic form 2 7 The sensitivity of stakeholders (including but not limited to students, faculty, staff, alumni, governing boards, legislators, donors, and funding agencies) to privacy 2 3 4 Level of regulation regarding security (international, federal, state, or local regulations) 1 4 3 1 Does your organization have academic or research programs in a sensitive area that may make you a target of violent physical or cyber attack from any groups? 5 1 2 1 Total score 1 9 6 7 22 Scoring: Very Low = 0; Low = 1; Medium = 2; High = 3; Very High = 4 Section II: Risk Management: This section assesses the risk management process as it relates to creating an information security strategy and program. Table 2: Information Security Risk Assessment Questions Scores/Frequency 0 1 2 3 4 Does your organization have a documented information security program? 2 5 2 Has your organization conducted a risk assessment to identify the key objectives that need to be supported by your information security program? 2 4 3 Has your organization identified critical assets and the functions that rely on them? 2 2 5 Have the information security threats and vulnerabilities associated with each of the critical assets and functions been identified? 2 4 2 1 Has a cost been assigned to the loss of each critical asset or function? 1 3 3 2 Do you have a written information security strategy? 2 4 2 1 Does your written information security strategy include plans that seek to cost-effectively reduce the risks to an acceptable level, with minimal disruptions to operations? 4 2 2 1 Is the strategy reviewed and updated at least annually or more frequently when significant changes require it? 2 3 3 1 Do you have a process in place to monitor federal, state, or international legislation or regulations and determine their applicability to your organization? 2 2 3 2 1 Total 10 16 26 14 16 Scoring: Not Implemented = 0; Planning Stages = 1; Partially Implemented = 2; Close to Completion = 3; Fully Implemented = 4 Section III: People This section assesses the organizational aspects of the information security program. Table 3: Information Security Function/Organization Questions Scores/Frequency 0 1 2 3 4 Do you have a person that has information security as his primary duty, with responsibility for maintaining the security program and ensuring compliance? 4 3 1 1 Do the leaders and staff of your information security organization have the necessary experience and qualifications? 5 2 2 Is responsibility clearly assigned for all areas of the information security architecture, compliance, processes and audits? 3 4 1 1 Do you have an ongoing training program in place to build skills and competencies for information security for members of the information security function? 2 2 3 2 Does the information security function report regularly to institutional leaders and the governing board on the compliance of the institution to and the effectiveness of the information security program and policies? 2 3 3 1 Are the senior officers of the institution ultimately responsible and accountable for the information security program, including approval of information security policies? 3 4 2 Total 16 17 14 7 0 Scoring: Not Implemented = 0; Planning Stages = 1; Partially Implemented = 2; Close to Completion = 3; Fully Implemented = 4 Section IV: Processes This section assesses the processes that should be part of an information security program. Table IV: Security Technology Strategy Questions Scores/Frequency 0 1 2 3 4 Have you instituted processes and procedures for involving the security personnel in evaluating and addressing any security impacts before the purchase or introduction of new systems? 2 3 3 1 Do you have a process to appropriately evaluate and classify the information and information assets that support the operations and assets under your control, to indicate the appropriate levels of information security? 1 2 3 2 1 Are written information security policies consistent, easy to understand, and readily available to administrators, faculty, employees, students, contractors, and partners? 2 3 3 1 Are consequences for noncompliance with corporate policies clearly communicated and enforced? 1 3 2 3 1 Do your security policies effectively address the risks identified in your risk analysis/risk assessments? 2 3 4 Are information security issues considered in all important decisions within the organization? 3 2 3 1 Do you constantly monitor in real time your networks, systems and applications for unauthorized access and anomalous behavior such as viruses, malicious code insertion, or break-in attempts? 1 3 3 1 1 Is sensitive data encrypted and associated encryption keys properly protected? 2 3 2 1 1 Do you have an authorization system that enforces time limits and defaults to minimum privileges? 2 2 2 3 Do your systems and applications enforce session/user management practices including automatic timeouts, lock out on login failure, and revocation? 2 3 2 2 Based on your information security risk management strategy, do you have official written information security policies or procedures that address each of the following areas? Individual employee responsibilities for information security practices 4 3 1 1 Acceptable use of computers, e-mail, Internet, and intranet 2 3 2 2 Protection of organizational assets, including intellectual property 2 2 3 2 Access control, authentication, and authorization practices and requirements 1 2 3 1 2 Information sharing, including storing and transmitting institutional data on outside resources (ISPs, external networks, contractors’ systems) 2 1 3 2 1 Disaster recovery contingency planning (business continuity planning) 1 1 3 4 Change management processes 2 3 2 2 Physical security and personnel clearances or background checks 1 3 3 2 Data backups and secure off-site storage 1 1 3 4 Secure disposal of data, old media, or printed materials that contains sensitive information 2 3 4 For your critical data centers, programming rooms, network operations centers, and other sensitive facilities or locations: 2 3 4 Are multiple physical security measures in place to restrict forced or unauthorized entry? 1 2 3 3 Is there a process for issuing keys, codes, and/or cards that require proper authorization and background checks for access to these sensitive facilities? 2 1 3 3 Is your critical hardware and wiring protected from power loss, tampering, failure, and environmental threats? 1 4 4 Total 17 45 58 50 47 Scoring: Not Implemented = 0; Planning Stages = 1; Partially Implemented = 2; Close to Completion = 3; Fully Implemented = 4 Discussion As shown by the total scores on Table 1, a majority of the university has a very high reliance on the IT in their services. This is depicted by the structure and characteristics of the university. Information risk assessment and management leaves a lot to be desired by the universities. Most the universities have partially implemented such programs. A large number of employees in the IT departments of most universities do no have sufficient skills to implement good information security governance. Most universities lack the leaders who have the rightful know how on the subject. In addition  to that, there is no a representative in the council who will be an IT expert, hence most leaders lack interest and initiatives on information security. Due to lack of full responsibility of information security by the leaders, to implement processes for information security might also be a challenge especially to the IT department as normally is the department given the responsibility. Conclusion There is a need for institutions to start focusing on proper information security governance. For a start organization such as the Government, the Computer Society of Zimbabwe, Zim Law Society, POTRAZ, ICAZ, IIAZ, Zimbabwe Institute of Management and other industry governing bodies should put their heads together and define the appropriate legislations that mandates information security governance either by referring to existing international frameworks (PCI-DSS, SOX, COSO, ITIL, SABSA, Cobit FIPS, NIST, ISO 27002/5, CMM, ITG Governance Framework) or by consulting local information security and business professionals to come up with an information security governance framework. As the Zimbabwean economy is slowly sprouting, the art of information security governance in the universities should also take a leap. The adoption information security governance will ensure that security will become a part of any university and thus customers confidence will be boosted. References Drucker, P. ‘Management Challenges for the 21st Century’, Harpers Business , 1993. 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