Television And Its Impact On Our Lives - 1818 Words

Introduction As any devices we use in our everyday life, television is a part that can provide many several opportunities to identify the concept of the world and how it goes as we are not being in everywhere around the world of course. The TV is a portal that teleports you to another dimension which may let you explore and see the variety of people’s ideas, beliefs, values and other significant things that some people believe in. Television can be defined as an extremely efficient style of interacting which has an ability to show kids to various experiences and thoughts that could be conceivable (Hancox, Milne Poulton, 2005). Television introduces many programs that children could be part of them like cartoons, movies series,†¦show more content†¦TV show can exchange the precious time that kids use for doing homework and reading the lessons that the school provides to feed their brains with the necessary knowledge to a time that children waste by watching cartoons and non-educat ional movie and other TV displays. According to Hancox, Milne and Poulton (2005), the time which the children waste watching those shows may change many educational activities like homework, reading or inventive games. Like the wisdom says† early start, grow smart†, Tv prevents children from keeping all the worthy information. Learning from educational institutions can be beneficial for young people and parents want the compatible approach for their children to earn knowledge so they can face the life after growing equipped the weapons that erase the ignorance from their dictionary. In 2005,Just like Hancox, Milne, Poulton said † higher IQ and socioeconomic status were associated with better educational outcomes†, the child’s brain is like a machine that needs the appropriate fuel to work and produce high quality of concepts and beliefs which can introduce the perspective of life whether in good or bad way and it depends on the fuel that the TV and pa rents provide for children. In other words, Tv can affect the understanding of concepts and if it is positive or negative for the age of the person, and the Acceptance of the method. Therefore, the child’s intelligence can be impacted depending on what the child is watching and whether isShow MoreRelatedTelevision And Its Impact On Society922 Words   |  4 Pagesmore pressing matters. Our society has been greatly influenced by the presence of television and how we see ourselves, it has also informed us of what the â€Å"norms of society† really are. Television has given us information on pop culture and many of today’s famous TV shows and celebrities. The impacts of television, and whether it is positive or negative have been debated for years, and it has still not come to a conclusive answer. Although many think that television has no impact on an individual, orRead MoreThe Truman Show By Peter Weir Essay1236 Words   |  5 Pagesto the interests of more pow erful people. If we want to live an authentic life and be free, we should put distance between ourselves and the comfort that is our media filled culture. We have to leave the safety that is the media’s grasp and be willing to live in the world the way it actually is. In the 1990’s, television culture in particular was in full swing. Television is such a powerful tool as it has the potential to heavily influence our mindsets on topics. The Truman Show showed us an exaggeratedRead MoreThe Impact of Reality Tv on the Teenagers1732 Words   |  7 PagesThe Impact Of Reality TV on the Teenagers in Mumbai Nimish Satpute St. Andrews College Instructors : Prof. Meenakshi Kamat : Prof. Jenny Benoy Abstract Reality-based television programming has become a dominant force in television over the past seven years and a staple of most networks’ primetime lineups. This relatively quick change in the television landscape and the sudden increase in viewers’ consumption of reality televisionRead MoreThe Effects Of Modern Media On Us1046 Words   |  5 PagesEverything in our society impacts us in one way or another; these influences can either be positive or negative. For example, when we see something good happen to others around us we tend to be in a happier mood and when something tragic happens to our country, such as what happened in 9/11, we can’t help but mourn. We never notice how the small things in life could influence us in big ways. We never would notice that things like modern media, such as television, ads, and the internet would impact us inRead MoreThe History of Television Essay1473 Words   |  6 PagesHistory of television and its influence on people lives. How did television revolutionize the world? TV, more commonly known as ‘television’ is one of the greatest inventions of the 20th century. In ancient Greek tà ¨le means ‘far, and in Latin visio means sight. From my perspective and many people of the world television has changed the way we live. Television has brought many amazing things, however nothing is perfect. Television sets were commercially available since the late 1920s but in veryRead MoreOrganizational Structure For A Television Station1266 Words   |  6 PagesHaving organizational structure for a television station can make your either easier, stress free, or both and can be helpful in the long run. For major networks like Fox, ABC, NBC, and CBS there has to be some sort of structure going on that keeps yours favorite channels up and running. Some roles that help keep the structure of television station would be the general manager, engineering, production manager, news director, and your sales manager. General Manager is the main person in charge alsoRead MorePositive And Negative Effects Of The Media1364 Words   |  6 Pagesallowing for communication. The abundance of technology such as cell phones, tablets, computers, and television has made the world much more connected than ever. Consequently, more and more Americans are becoming dependent on such devices that make daily tasks easier. Through these connections, the media is able to implement itself into everyday lives, and although these advancements improve peoples lives, there are aspects that are negative. The media tends to be enjoyed for the benefits it offers withRead MoreEssay about Television as We Know it Today1035 Words   |  5 PagesTelevision as We Know it Today The Power Rangers, RoadRunner, Bugs Bunny and Yo Sammity Sam. What do all of these have in common? They are all shows upon which we build our child’s playtime. You sit your child in front of the television for hours at a time. They stair at the screen with glossy eyes and total amazement. Yet what is it that they are learning from these shows? It is the hidden message of violence and dysfunction, which keeps children entertained. If you look at all of the showsRead MoreThe Media s Role Into The Lives Of Our American Youth1405 Words   |  6 Pageswe as a society live and interact with each other on a daily basis. According to oxford dictionaries media is defined as the main means of mass communication (especially television, radio newspapers and the internet). A facet of social media that people all over the world see is television. To get the latest news whether its political, local or even social, millions of people tune into their televisions everyday. I’m intereste d to know â€Å"what is the media’s role into the lives of our American youthRead MoreMean World1027 Words   |  5 Pagesâ€Å"Mean World Syndrome† Everyone is influenced and shaped by society. Society affects our perceptions, our consciousness, and our actions. A majority of the influence, especially on the younger demographic comes through the media; specifically through television. It is important to examine how violence in the media develops a pervasive cultural environment that cultivates a heightened state of insecurity, exaggerated perceptions of risk and danger, and a fear-driven propensity for hard-line political

Analysis Of The Story Cuba - 1217 Words

The story of Cuba is a very interesting one. Most are familiar with it as a small island in the Caribbean. Those who have not been completely negligent over the last half a century have probably also heard the names Fidel Castro and Ernesto â€Å"Che† Guevara. These two men were very pivotal players in the history of Cuba and its revolution. Literary and cinematic reenactments are a great method for providing historical knowledge. However, they can be heavily biased and much of the factual evidence can be â€Å"silenced† throughout the films and novels. Cuba has always been a region of great interest due to its location in the Caribbean Sea. The nation resisted capitalism for over forty-five years and aside from North Korea, is the last to be†¦show more content†¦The issue in previous years was that the economy was placed low on the list of priorities. However, in the late ‘60s we see that steadying the economy became their main focus. Attempts at economi c diversification through industrializing the nation were made at the expense of the agricultural industry. This new push towards technology and modern machinery was consuming nearly a quarter of the national income. The government was caught between a rock and a hard place. It needed the sugar income to pay for expansion, but it had ignored agriculture which was their way to fund. Failure to put emphasis on agriculture led to the decline of sugar harvest in which their output dropped nearly in half over a couple years. Government at the time consisted of a small amount of state officials and administrators which held a monopoly over all major decisions affecting societal and economic issues. The bulk of the population had no voice in the decision-making process. Nor could they remove the officials from their positions. Fidel Castro, among other bureaucrats used the Communist Party to pursue their economic agendas. Anyone questioning their priorities was accused of being anti-revolu tionary. Cuba turned to the Soviet Union for their economic and political ideals. Socialism had failed to develop an economy capable of sustaining Cuba. There were problems with the Soviets, whom the Cubans did not always get along with. In 1968, nearly forty members of the Communist Party

Forensic Entomology Decomposition

Question: Describe about the Forensic Entomology for Decomposition. Answer: The change in the body as a food resource as it decays from death to skeleton. The process by which organic materials break down into simpler matter is called decomposition. Shortly after death the body of living organisms starts to decompose. Although no organisms decompose in a similar way they all undergo specific steps of decomposition. There are two forms of decomposition namely abiotic and biotic. Abiotic refers to degradation of a matter through physical or chemical processes, for example hydrolysis. Biotic is the metabolic breakdown of substances by living organisms into simpler components practically by microorganisms. There are five general stages that describe the decomposition process of vertebrate animals. These processes are namely fresh, bloat, active decay, advanced decay and dry remains. The five stages work hand in hand with the chemical decomposition stages i.e. putrefaction and autolysis. Fresh Immediately after the heart of a living thing stops beating the fresh stage kicks off. In case an individual with cardiopulmonary resuscitation skills happens to be around during death a person can be revived. After the period of death the body starts warming or cooling to march the ambient environment temperature in staged referred to as algor mortis. Between 3-6 hours muscular tissues become rigid and cannot relax at the rigor mortis stage. As there is no more blood circulation around the body it is caused to drain to the dependent body portions due to the gravity force. A bluish-purple discoloration referred to as livor mortis (lividity) is formed. At this point there is no supply of oxygen or removal of carbon dioxide to and from body tissues. As a result there is decrease in pH which leads to deformity of body cells. Cells therefore release enzymes that are able to start breakdown of surrounding tissues and cells through autolysis. During this stage there are visible changes although sometimes blisters may appear on the body as result of autolysis. Multiplying anaerobic organisms while consuming proteins, lipids and carbohydrates to produce substances like hydrogen sulphide, propionic acid, methane, ammonia and lactic acid. This process is called putrefaction which leads to the bloat stage. Bloat At this stage there is a visual sign that indicated a potential microbial proliferation. Gases accumulation within the body cavity causes a bloated appearance to the cadaver. As a result of the gases, liquids are formed which cause the tissues to be frothy. The formed liquids are force to emanate from natural openings like nose, anus and mouth due to the increased pressure of gases. The pressure might also cause the body to rapture. Haemoglobin is transformed into sulfhemoglobin by intestinal anaerobic bacteria. Sulfhemoglobin circulates through the body giving it a marbled appearance. If insects have access to the body maggots hatch and start to feed on the tissues. The skin slips and hair detachment occurs as a result of the maggot activity. The ruptured skin allows oxygen to enter into the body which facilitates larvae development and microorganism activities. Odors that are associated to decaying are produced by the purging fluids and gases. Active decay At this stage there is a great mass loss to the body. This loss is as a result of the maggot feeding and purging of the fluid into the environment. A cadaver decomposing island (CDI) is created due to accumulation of purged fluids inside the body. The odors become stronger due to the apparent disintegration and liquefaction of tissues. Migration of the maggots from the body signals the end of active decay. Advanced decay At this stage severe occurs causing the loss of cadaveric material that was readily available. Insect activity is reduced at this stage. Vegetation death is seen in the surrounding area if the carcass was placed on the ground. There is improved soil carbon and nutrients in the CDI surrounded by carcass. Such nutrients are calcium, magnesium, phosphorus and potassium. There is also a change in pH and soil nitrogen is increased. Dry remains Cartilage, bones and dry skins are the only remains of cadaver in this stage. They become bleached and dry if they are exposed to the elements. The cadaver is termed as skeletonised if all soft tissue is removed. If only a few parts of bones are showing the cadaver is partially is skeletonised. The change in insect fauna visiting over that same period of time Shortly after death insects are attracted to the corpse and they might lay eggs in it. Different kind of insects can be found on decaying body according to Smith (1986). i) necrophagus species which feed on the body, ii)parasites and predators which eat necrophagous species including schizophagus species which feed on the body and turn to predators on later stages, iii) omnivorous species which feed on the body and fellow arthropods e.g. wasps, beetles and ants. The succession through which insects attack the body depend on the condition of carrion decomposition. At fresh stage insects are attracted to the body within the first ten minutes but there is no laying of eggs at this particular period. Cellular breakdown takes place at this stage with no morpholic alterations. At this early stage chemical resulting from cellular breakdown attracts insects. During the bloated stage carcass internal temperatures rise due to putrefaction and arthropod activities. It is at this stage that the highest numbers of adult Diptera attack the carcass. At the start of the 2nd day a lot of predators of Diptera larvae are present in the carcass. By day four larval stages Diptera are also available. At day ten there is a substantial decrease of the carcass weight. Carcass biomass is converted into dipteran larval biomass. The larvae successively leave the decomposing body to pupate. In the post decay stage which occurs between day ten and day twenty-three a good number of Diptera larvae depart from the carcass leaving behind tiny tissue portion, big wet amount, cartilage, bones, hair, viscous material called by products of decay (BOD). By product of decay is the main arthropod activity at this stage. During remains stage which is between the period of eighteen to ninety plus days, bones with little cartilage remaining and a dried up by product of decay (BOD) are the characteristics observed. Post decay transition remains stage is steady with reducing larval and adult Diptera population. References Halber, D. (2014). The Skeleton Crew: How Amateur Sleuths Are Solving Americas Coldest Cases. New York City: Simon and Schuster. Museum, I. S. (2009). The Living Museum, Volume 61. Chicago: Illinois State Museum, . Payne-James, J. (2005). Encyclopedia of Forensic and Legal Medicine: Cr-H. Cambridge: Elsevier Academic Press,. Shanks, M. (Abingdon-on-Thames). Experiencing the Past: On the Character of Archaeology. 2012: Psychology Press. University, P. (2008). Waldie's Select Circulating Library, Volume 12. Toronto: A. Waldie. Waldie, A. (Toronto). Waldie's Select Circulating Library, Volume 12. 2009: A. Waldie.

Data Communication and Networking free essay sample

It is the exchange of data between two devices via some form of transmission medium such as wire cable. The communicating system must be part of a communication system made up of a combination of hardware and software. The effectiveness of a data communication system depends on three fundamental characteristics: delivery, accuracy and timeliness. 2. What is simplex? Ans: It is the mode of communication between two devices in which flow of data is unidirectional. i. e. one can transmit and other can receive. E. g. eyboard and monitor. It is the mode of communication between two devices in which flow of data is bidirectional but not at the same time. ie each station can transmit and receive but not at the same time. E. g walkie-talkies are half-duplex system. 4. What is full duplex? Ans: It is the mode of communication between two devices in which flow of data is bidirectional and it occurs simultaneously. Here signals going in either direction share the capacity of the link. E. g. telephone 5. What is a network? Ans: It is a set of devices connected by communication links. A node can be a computer or any other device capable of sending and/or receiving data generated by other nodes on the network. 6. What is distributed processing? Ans: It is a strategy in which services provided by the network reside at multiple sites. 7. What is point to point connection? Ans:It provides a dedicated link between two devices. The entire capacity of the link is reserved for transmission between the two devices e. g. when we change the TV channels by remote control we establish a point to point connection between remote control and TV control system. . What is multipoint connection? Ans: In multipoint connection more than two specific devices share a single link. Here the capacity of the channel is shared either separately or temporally. 9. What is a topology? Ans: Topology of a network is defined as the geometric representation of the relationship of all the links and linking devices (node) to one another. Four basic topologies are star, bus, ring and mesh. Star – Here each device has a dedicated point to point link only to a central controller called hub. Bus -It is multipoint. One long cable acts as a backbone to link all the devices in the network. Ring -Here each device has a dedicated point to point connection only with the two devices on either side of it. Mesh -Here every device has a dedicated point to point link to every other device. 10. Define LAN, MAN and WAN. Ans: LAN- A local area network (LAN) is a privately owned and links the devices in a single office, building or campus. It allows resources to be shared between personal computers and work stations. MAN- A metropolitan-area network (MAN) spreads over an entire city. It may be wholly owned and operated by a private company, eg local telephone company. WAN – A wide area network (WAN) provides long distance transmission of data, voice, image and video information over large geographic areas that comprise a country, a continent or even whole world. 11. Define internet? Ans: It is a network of networks. 12. What is a protocol? Ans: It is a set of rules that governs data communication. A protocol defines what is communicated, how it is communicated, and when it is communicated. The key elements of protocol are syntax, semantics and timing. 13. What is TCP/IP protocol model? Ans: It is a five layered model which provides guidelines for the development of universally compatible networking protocols. The five layers are physical, data link, network, transport and application. 14. Describe the functions of five layers? Ans: Physical- It transmits raw bits over a medium. It provides mechanical and electrical specification. Data link- It organizes bits into frames. It provides hop to hop delivery. Network-It moves the packets from source to destination. It provide internetworking. Transport-It provides reliable process to process message delivery and error recovery. Application-It allows ti access to network resources. 15. What is ISO-OSI model? Ans: Open Systems Interconnection or OSI model was designed by the International Organization for Standardization (ISO) . It is a seven layer model. It is a theoretical model designed to show how a protocol stack should be implemented. It defines two extra layers in addition to TCP/IP model. Session -It was designed to establish, maintain, and synchronize the interaction between communicating system. Presentation-It was designed to handle the syntax and semantics of the information exchanged between the two systems. It was designed for data translation, encryption, decryption, and compression. 16. What is multiplexing? Ans: Multiplexing is the process of dividing a link, the physical medium, into logical channels for better efficiency. Here medium is not changed but it has several channels instead of one. 16. What is switching? Ans: Switching in data communication is of three types Circuit switching Packet switching Message switching 17. How data is transmitted over a medium? Ans: Data is transmitted in the form of electromagnetic signals. 18. Compare analog and digital signals? Ans: Analog signals can have an infinite number of values in a range but digital signal can have only a limited number of values. 19. Define bandwidth? Ans: The range of frequencies that a medium can pass is called bandwidth. It is the difference between the highest and lowest frequencies that the medium can satisfactorily pass. 20. What are the factors on which data rate depends? Ans: Data rate ie. how fast we can send data depends upon i) Bandwidth available ii) The levels of signals we can use iii) The quality of the channel (level of noise) 21. Define bit rate and bit interval? Ans: Digital signals are aperiodic. o instead of using period and frequency we use bit interval and bit rate respectively. Bit interval is the time required to send one single bit. Bit rate is the number of bit intervals per second. 22. What is Nyquist bit rate formula? Ans: For a noiseless channel, the Nyquist bit rate formula defines the theoretical maximum bit rate Bitrate=2* Bandwidth*log2L Where Bandwidth is the bandwidth of the channel L is the number of signal level used to represent the data Bitrate is the bit rate in bits per second. 23. Define Shannon Capacity? Ans: Shannon Capacity determines the theoretical highest data rate foe a noise channel. Capacity= Bandwidth * log2 (1+SNR) Bandwidth is the bandwidth of the channel. SNR is the signal to noise ratio, it is the statical ratio of the power of the signal to the power of the noise. Capacity is the capacity of the channel in bits per second 24. What is sampling? Ans: It is the process of obtaining amplitude of a signal at regular intervals. 25. Define pulse amplitude modulation? Ans: It is an analog to digital conversion method which takes analog signals, samples it and generates a series of pulse based on the results of the sampling. It is not used in data communication because the series of pulses generated still of any amplitude. To modify it we use pulse code modulation. 26. Define pulse code modulation? Ans: Pulse code Modulation modifies pulses created by PAM to create a completely digital signal. For this PCM first quantizes the PAM pulse. Quantization is the method of assigning integral values in a specific tange to sampled instances. PCM is made up of four separate processes: PAM, quantization, binary encoding and line encoding. According to this theorem, the sampling rate must be at least 2 times the highest frequency of the original signal. 8. What are the modes of data transmission? Ans: Data transmission can be serial or parallel in mode In parallel transmission, a group of bits is sent simultaneously, with each bit on a separate line. In serial transmission there is only one line and the bits are sent sequentially. 29. What is Asynchronous mode of data transmission? Ans: It is a serial mode of transmission. In this mode of transmission, each byte is framed with a start bit and a stop bit. There may be a variable length gap between each byte. 30. What is Synchronous mode of data transmission? Ans: It is a serial mode of transmission. In this mode of transmission, bits are sent in a continuous stream without start and stop bit and without gaps between bytes. Regrouping the bits into meaningful bytes is the responsibility of the receiver. 31. What are the different types of multiplexing? Ans: Multiplexing is of three types. Frequency division multiplexing and wave division multiplexing is for analog signals and time division multiplexing is for digital signals. 32. What is FDM? Ans: In frequency division multiplexing each signal modulates a different carrier frequency. The modulated carrier combines to form a new signal that is then sent across the link. Here multiplexers modulate and combine the signal while demultiplexers decompose and demodulate. Guard bands keep the modulating signal from overlapping and interfering with one another. 32. What is TDM ? Ans: In TDM digital signals from n devices are interleaved with one another, forming a frame of data. Framing bits allow the TDM multiplexer to synchronize properly. 33. What are the different transmission media? Ans: The transmission media is broadly categorized into two types i)Guided media(wired) i)Unguided media(wireless) 34. What are the different Guided Media? Ans: The media which provides a conduct from one device to another is called a guided media. These include twisted pair cable, coaxial cable, and fiber-optic cable. 35. Describe about the different Guided Medias. Ans: Twisted pair cable consists of two insulated cupper wires twisted together. It is used in telephone line for voice and data communications. Coaxial cable has the following layers: a metallic rod-shaped inner conductor, an insulator covering the rod, a metallic outer conductor (shield), an insulator covering the shield, and a plastic cover. Coaxial cable can carry signals of higher frequency ranges than twisted-pair cable. Coaxial cable is used in cable TV networks and Ethernet LANs. Fiber-optic cables are composed of a glass or plastic inner core surrounded by cladding, all encased in an outer jacket. Fiber-optic cables carry data signals in the form of light. The signal is propagated along the inner core by reflection. Its features are noise resistance, low attenuation, and high bandwidth capabilities. It is used in backbone networks, cable TV nerworks, and fast Ethernet networks. 36. What do you mean by wireless communication? Ans: Unguided media transport electromagnetic waves without using a physical conductor. This type of communication is referred as wireless communication. Here signals are broadcaster through air and thus available to anyone who has a device to receive it. 37. What do you mean by switching? Ans: It is a method in which communication devices are connected to one another efficiently. A switch is intermediary hardware or software that links devices together temporarily. 38. What are the switching methods? Ans: There are three fundamental switching methods: circuit switching, packet switching, And message switching. In circuit switching, a direct physical connection between two devices is created by space division switches, time division switches or both. In packet switching data is transmitted using a packet switched network. Packet switched network is a network in which data are transmitted in independent units called packets. 39. What are the duties of data link layer? Ans: Data link layer is responsible for carrying packets from one hop (computer or router) to the next. The duties of data link layer include packetizing, adderssing, error control, flow control, medium access control. What are the types of errors? Ans: Errors can be categorized as a single-bit error or burst error. A single bit error has one bit error per data unit. A burst error has two or more bits errors per data unit. 41. What do you mean by redundancy? Ans: Redundancy is the concept of sending extra bits for use in error detection. Three common redundancy methods are parity check, cyclic redundancy check (CRC), and checksum. 42. Define parity check. Ans: In parity check, a parity bit is added to every data unit so that the total number of 1s is even (or odd for odd parity). Simple parity check can detect all single bit errors. It can detect burst errors only if the total number of errors in each data unit is odd. In two dimensional parity checks, a block of bits is divided into rows and a redundant row of bits is added to the whole block. 43. Define cyclic redundancy check (CRC). Ans: C RC appends a sequence of redundant bits derived from binary division to the data unit. The divisor in the CRC generator is often represented as an algebraic polynomial. 44. What is hamming code? Ans: The hamming code is an error correction method using redundant bits. The number of bits is a function of the length of the data bits. In hamming code for a data unit of m bits, we use the formula 2r gt;= m+r+1 to determine the number of redundant bits needed. By rearranging the order of bit transmission of the data units, the hamming code can correct burst errors. 45. What do you mean by flow control? Ans: It is the regulation of sender’s data rate so that the receiver buffer doesn’t become overwhelmed. i. e. flow control refers to a set of procedures used to restrict the amount of data that the sender can send before waiting for acknowledgement. 46. What do you mean by error control? Ans: Error control refers primarily to methods of error detection and retransmission. Anytime an error is detected in an exchange, specified frames are retransmitted. This process is called automatic repeat request (ARQ). 47. Define stop and wait ARQ. Ans: In stop and wait ARQ, the sender sends a frame and waits for an acknowledgement from the receiver before sending the next frame. 48. Define Go-Back-N ARQ? Ans: In Go-Back-N ARQ, multiple frames can be in transit at the same time. If there is an error, retransmission begins with the last Unacknowledged frame even if subsequent frames arrived correctly. Duplicate frames are discarded. 49. Define Selective Repeat ARQ? Ans: In Selective Repeat ARQ, multiple frames can be in transit at the same time. If there is an error, only unacknowledged frame is retransmitted. 50. What do you mean by pipelining, is there any pipelining in error control? Ans: The process in which a task is often begun before the previous task has ended is called pipelining. There is no pipelining in stop and wait ARQ however it does apply in Go-Back-N ARQ and Selective Repeat ARQ. 51. What is HDLC? Ans: It is a bit oriented data link protocol designed to support both half duplex and full duplex communication over point to point and multi point links. HDLC is characterized by their station type,configuration and their response modes. 52. What do you mean by point to point protocol? Ans: The point to point protocol was designed to provide a dedicated line for users who need internet access via a telephone line or a cable TV connection. Its connection goes through three phases: idle, establishing, authenticating, networking and terminating. At data link layer it employs a version of HDLC. 53. What do you mean by point to point protocol stack? Ans: Point to point protocol uses a stack of other protocol to use the link, to authenticate the parties involved, and to carry the network layer data. Three sets of protocols are defined: link control protocol, Authentication protocol, and network control protocol. 54. What do you mean by line control protocol? Ans: It is responsible for establishing, maintaining, configuring, and terminating links. 55. What do you mean by Authentication protocol? Ans: Authentication means validating the identity of a user who needs to access a set of resources. It is of two types i)Password Authentication Protocol(PAP) ii)Challenge Handshake Authentication Protocol(CHAP) PAP is a two step process. The user sends a authentication identification and a password. The system determines the validity of the Information sent. CHAP is a three step process. The system sends a value to the user. The user manipulates the value and sends the result. The system Verifies the result. 56. What do you mean by network control protocol? Ans: Network control protocol is a set of protocols to allow the encapsulation of data coming from network layer protocol that requires the services of PPP. 57. What do you mean by CSMA? Ans: To reduce the possibility of collision CSMA method was developed. In CSMA each station first listen to the medium (Or check the state of the medium) before sending. It can’t eliminate collision. 58. What do you mean by Bluetooth? Ans: It is a wireless LAN technology designed to connect devices of different functions such as telephones, notebooks, computers, cameras, printers and so on. The internet address (IP ddress) is 32bits that uniquely and universally defines a host or router on the internet. The portion of the IP address that identifies the network is called netid. The portion of the IP address that identifies the host or router on the network is called hostid. 60. What do you mean by subnetting? Ans: Subnetting divides one large network into several smaller ones. It adds an intermediate level of hierarchy in IP addressing. 61. What are the advantages of fiber optics cable ? Ans: The advantages of fiber optics cable over twisted pair cable are Noise resistance-As they use light so external noise is not a factor. Less signal attenuation-fiber optics transmission distance is significantly greater than that of other guided media. Higher bandwidth-It can support higher bandwidth. 62. What are the disadvantages of fiber optics cable? Ans: The disadvantages of fiber optics cable over twisted pair cable are Cost-It is expensive Installation/maintenance-Any roughness or cracking defuses light and alters the signal Fragility-It is more fragile. 63. What are the propagation type of radio wave ? Ans: Radio wave propagation is dependent upon frequency. There are five propagation type. )surface propagation ii)Tropospheric propagation iii)Ionospheric propagation iv)Line of sight propagation v)space propagation 64. What do you mean by Geosynchronous Satellites ? Ans: Satellite communication uses a satellite in geosynchronous orbit to relay signals. The Satellite must move at the same speed as the earth so that it seems to remain fixed above a certain spot.. Only one orbit can be geosynchronous. This orbit occurs at the equatorial plane and is approximately 22,000 miles from the surface of earth. 65. What are the factors for evaluating the suitability of the media ? Ans: The factors are cost,throughput,attenuation,Electromagneric interference(EMI),securtty. 66. What do you mean by medium access control(MAC) sublayer. Ans: The protocols used to determine who goes next on a multi-access channel belong to a sublayer of the data link layer is called the multi-access channel(MAC) sublayer. It is the buttom part of data link layer. 67. What do you mean by ALOHA ? Ans: It is the method used to solve the channel allocation problem . It is used for: i)ground based radio broadcasting ii)In a network in which uncoordinated users are competing for the use of single channel.