My Experience Of My Flight - 873 Words

As I sit in the airport, my eyes scan the scene. I begin to watch people as they walk past me. Some are in a hurry; some could care less if they make it to their gate on time. You begin to categorize different types of people as they walk, or run, past you. As I learn that my flight has been delayed for another three hours, I take a seat against the wall and start to make a list, a list of the different types of people in the airport. â€Å"What do you think we will do when we get to the hotel†, said my mom. Being caught off guard, I say, â€Å"Hmm?† â€Å"I said, what do you think we will do once we get to the hotel?† â€Å"I don’t know! I will honestly just want to sleep after the day that we’ve had.† â€Å"You’re probably right. Should we just order room service, and then call it a night?† At this point, I start to tune her out because if I don’t, she will talk for hours. I reach for my backpack sitting next to me, and I take out my notebook. At the top, I title it, People in the Airport. I begin to write down different types of people. The ones who can’t figure out how an airport works. The ones who inch their way closer and closer, hoping to board sooner. The ones who bring way more then they need to. There are multiple different types of people in the airport. Here are just a few: The Lost Ones The lost ones are those who have no idea where they are going. They wander around aimlessly trying to get to their gate, but the only problem is, they don’t know where it’s at. Like do they notShow MoreRelatedThe Crucible, By Warren Bennis And Robert Thomas Essay1397 Words   |  6 PagesMy crucible experience was serving as a flight commander in the Euro-NATO Joint Jet Pilot Training Program (ENJJPT). This was one of the most challenging leadership roles that I have been placed in, primarily because of the range of individuals that I was leading. It was not a lot of people, especially compared to Army leadership positions, but it was an interesting and challenging mix of individual types. While there are countless events that contributed to my overall learning experience, I willRead MoreFemale Filight Attendant Cover Letter Sample996 Words   |  4 PagesFemale Flight Attendant Cover Letter Sample 322 Example Street Newark, NJ 65211 January 22, 2012 Mr. John Doe, Human Resources Manager ExpressJet Newark, NJ 65214 Re: Flight Attendant (Job ID 878) Dear Mr. Doe: Your Flight Attendant position, as advertised in The Daily Express, caught my attention because it involves the challenge of providing excellent customer service. I have been seeking just such a great opportunity and I think my background in hospitality and customer service sectorRead MoreMy Life Flight Nurse Is Not A Smoke Jumper1722 Words   |  7 Pagesrealize what we want to be. 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Since technology has been developed, people’s lives have also been changed. One of the examples is that manyRead MoreThe Genre Of Dance And The Flights Of Fancy Piece Was Ballet933 Words   |  4 PagesThe genre of dance that was represented in the Flights of Fancy piece was ballet. This amazing piece was choreographed by Lisa A. Fusillo and was accompanied with music by Antonin Dvorak. I knew that Flights of Fancy was a ballet number because many of the dancers used the alignment of their heads, shoulders, and hips to execute ballet technique. The use of a turnout was used in most of the choreography and it showed clean footwork, perfect angles, and gorgeous lines. In order for these dancers toRead MoreSummary on Service Encounter Journal1242 Words   |  5 Pagessix weeks, I realized my interaction with the serv ice providers played a vital role in improving my perceptions regarding service quality, as they also influenced my satisfaction and brand perception. 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Question 1.1. Explain The Sequence And Rate Of Each Aspect

Question 1.1: Explain the sequence and rate of each aspect of development from birth – 19 years: There are five aspects of a child and young person’s development that are measured on, Social development, physical development, intellectual development, communication, and emotional development. Development refers not to the physical growth of children and young people, but to the skills and knowledge that they are developing. All children and young people follow a similar pattern of development so the order in which each child grows from one milestone to the next will roughly be the same. However, each child will develop at a different rate and their development may not progress evenly across all areas. Physical development Physical†¦show more content†¦Between the ages of 6 and 7 years old they will use fine motor skills which may include putting a jigsaw together, putting cloths on and off and using buttons, they can kick and control a ball, use a knife and fork competently, but will need help to cut meat up. From ages 8-9 children will increased body strength and co-ordination and have a quicker reaction time, they can ride a two-wheeled bike, skip more freely, enjoy active, energetic games and sports, and will enjoy participating in competitive sports. They will have more control over small muscles and therefore write and draw with greater skill, drawing with more details, and are beginning to join letters together in handwriting. Age 10 and 11 years will differ in physical maturity because girls experience puberty earlier generally as much as 2 years ahead of boys, they will start to have body’s proportions that are becoming like those of adults. During adolescence, young people go through many changes as they move from childhood into teenagers, between the ages of 11-16 young girl’s breasts will have started to develop and will have fully develop between 12-18 years old. A girl’s menstrual cycle may start as early as 10 years old and as late as 15. Pubic, armpi t hair and underarm hair will grow like that of an adult. At 13-14 years, boys may notice that their testicles and scrotum are growing and by the age 16 or 17 the genitals are usually at their adult size. Armpit, pubic, leg, chest, and facial hairShow MoreRelatedExplain the Difference Between Sequence of Development and Rate of Development and Why the Difference Is Important.1465 Words   |  6 PagesCYP3.1 Outcome 1.2 Explain the difference between sequence of development and rate of development and why the difference is important. It is important to know the difference between the sequence and the rate of development as it helps to identify the Childs needs during the stages of their school years. It is crucial to plan effectively ensuring the child receives the support they need in the areas they find most difficult in, for example physical development shows a pacific pattern; a babyRead MoreShould Hire Jill For The Position Of `` Floating `` Administrative Assistant?1697 Words   |  7 Pageswill take a survey from current business supervisors and managers within the United States. The results from the survey will help me understand how others would manage the above scenario. I will design the questions in the survey to not reveal any bias. However, I will word the questions to acknowledge my theory, â€Å"not to hire additional individuals with a disability to the small firm.† Part III: Hypothesis and Survey Design: My hypothesis ask if, â€Å"Most people believe that employers perceiveRead MoreExplain the sequence and rate of each aspect of development that would normally be expected in children and young people from birth - 19 years3072 Words   |  13 Pagesï » ¿Unit Title MU 5.2 Assessment Criteria 1.1 Explain the sequence and rate of each aspect of development that would normally be expected in children and young people from birth – 19 years. Physical development is the increase in size which takes place as a child develops. It is the way the body increases in skill and becomes more complex in its performance. Whole body movements are described as gross motor skills and fine motor skills are the use of hands in co-ordination with theRead MoreEssay on Level 3 Childrens and Young Peoples Workforce Assignment 0234376 Words   |  18 Pagesand assessment criteria for Unit 022, Understand Child and Young Person Development. Tasks There are five tasks to this assignment. A Complete tables; Questions B Complete table; Report C Report D Report E Complete table Assignment coverage Task | Task name | Learning outcomes covered | A | A Complete tables; Questions | 1. Understand the expected pattern of development for children and young people birth – 19 years | B | B Complete table; Report | 2. Understand the factorsRead MoreUnderstand Child and Young Person Essay1816 Words   |  8 Pagespattern of development for children and young people from birth - 19 years. 1.1 Physical Development, Communication and Intellectual development. Social, emotional and behavioural development. All babies, children and young people follow the same pattern when it comes to development but each person is unique. Every day they will grow, develop and learn at there own pace but following a similar basic pattern in their sequence of development. A child’s development can be measured through social, emotionalRead MoreEdmondson2152 Words   |  9 PagesLimited (APIL), is mixing  new  shades to emerge with winning colors. Says their Managing director: With proper planning and a comprehensive approach to issues, we intend to keep pace with the growth of the industry. APIL is actually targeting a growth rate that is higher than the 9 to 10 per cent that the industry has been averaging  recently. APILs approach is multipronged: expansion of its product range and introduction of value added, niche  products  in the industrial paints area; line extensionsRead MoreEdmondson2139 Words   |  9 PagesLimited (APIL), is mixing  new  shades to emerge with winning colors. Says their Managing director: With proper planning and a comprehensive approach to issues, we intend to keep pace with the growth of the industry. APIL is actually targeting a growth rate that is higher than the 9 to 10 per cent that the industry has been averaging  recently. APILs approach is multipronged: expansion of its product range and introduction of value added, niche  products  in the industrial paints area; line extensionsRead MoreIct 231 Exam Marking Guide5022 Words   |  21 PagesPART 1 - Multiple Choice (25 MARKS) Each item has one correct answer. Mark your answers to questions 1 to 50 on the computer answer sheet. 1. ____ is the process of understanding and specifying in detail what an information system should accomplish. a. Systems design b. Automation c. Systems analysis d. Strategic planning 2. The ______ is an object-oriented system development methodology offered by IBM’s Rational Software. a. Unified Process b. structured system c. class diagram Read MoreCapstone Project3045 Words   |  13 PagesCAPSTONE PROJECT WRITING GUIDE Chapter | Subsections | What to write | Sample Output | Introduction | 1.1 Project Context | a. Set the basic context * What is the big picture for the problem you are working with? b. State the research Question * What will you do in your project and what problem will you solve? c. Summarize your approach *how will you do that? | Cloud computing is considered to be a new computing paradigm where applications, data and Information Technology servicesRead MoreUnderstand Child Development and Young Person Development - 1.12161 Words   |  9 PagesDevelopment Rosanna King Learning Outcome 1: Understand the expected pattern of development for children and young people from birth – 19 years. Assessment Criteria 1.1: Explain the sequence and rate of each aspect of development from birth – 19 years. Answer to 1.1: Below I have explained the sequence and rate of each development from birth – 19 years old in great detail. 0-2 Years – Physical Development: * The baby lies supine (1 month old) * The baby turns its head towards

Essay on The Importance of Human Evolution - 1794 Words

Introduction The main purpose of this essay is to critically discuss the importance of an understanding of human evolution and the history of psychology for the modern psychologist. The essay aims to critically discuss the study of human evolution which includes some of the species that evolved over the years before we now have our species, the history of psychology and the different prominent figures that are responsible for psychology being the field it is today. Finally, how an understanding of this can aid a modern psychologist. To conclude, this essay will collate previous research done on human evolution, history of psychology and the importance of this for the modern psychologist. Human Evolution Human evolution started with Charles†¦show more content†¦The next major species found after the Australopithecus was the Homo habilis. Around the same time period they came into existence, two other species were present, homo rudolfensis (Alexeev 1986) and homo ergaster (Archaeology Information n.d). The brain size of Homo habilis was about 590-687 cc, unlike the Australopithecus they should evidence of tool usage (Tobias 1987). The homo ergaster species has a brain size of approximately 860cc (Australian museum n.d). They also showed evidence of tool making and there was a possibility of vocalization (). It is evident through this how the species are becoming more and more progressive, from the first species discussed not showing evidence of tool making and their brain size getting larger as each species is evolving. The next set of species is the homo Neanderthalensis; they evolved from a species named homo Heidelbergensis, who were thought to be the first species that acquired protolanguage (de Beaune et al. 2009). Homo Neanderthals had a brain size was about 1100-1400 cc (Holloway, Sherwood and Hof et al 2009). They showed evidence of tool usage; they were able to cope with frequent and dramatic changes in climate/ scenery () This shows that they were more able to adapt to environmental changes than the previous species discussed.() The Neanderthals first showed evidence of burial of the dead with gifts and also care for the elderly; this is an indication of social and cognitive abilities as they were ableShow MoreRelatedHow Organisms Evolved From a Common Ancestors1101 Words   |  5 PagesOne of the most important principles of biology is the main idea of evolution. This theory states, â€Å"that all living organisms have evolved from a common ancestor through natural selection acting on hereditary variation† (Reece, 2011). Many people today, know humans have evolved from a common ancestor; but they do not recognize the importance of it. Everyone should be educated about how organisms evolved because humans have evolved throughout many centuries. 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It is necessary to consider the true role of stochasticity in evolution, first in the frameRead MoreTatianas Sex Advice for All Creations by Olivia Hudson1606 Words   |  6 PagesOlivia Hudson is not only informative, and interesting but humorous and revealing. Throughout this book it explains why all creatures, not only humans, are interested in their sex life. Sex itself, and the reproduction process is why certain breeds are carried through century after century and others go extinct. Hudson has a way of explaining the importance of performance, timing, technique, and interest when it comes to sex, and how all of these concepts make a huge difference in those who have theRead MoreInto the Jungle Essay1003 Words   |  5 Pagesfor more information about these fascinating fish. 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However, theories with more evidence suggest that the iconic monolith doesn’t represent aliens or â€Å"God†, but instead represents the cinema screen of which we are viewing. The artistic importance of â€Å"2001: A SpaceRead MoreWithin On Liberty By John Stuart Mill1312 Words   |  6 PagesWithin On Liberty by John Stuart Mill, the notion of individuality and o ne s abilities to make choices for himself contradicts the notion of evolution within Edward O. Wilson’s Consilience. Mill’s beliefs derive from social interaction and experience in which the individual can decide for himself what is right versus what is wrong and can act upon what he believes to be the best option. Whereas, Wilson’s views coincide with the idea that individuals generate decisions based off of historically discoveredRead MoreEvolution And Evolution Of Evolution884 Words   |  4 Pages Evolution Evolution, a change in the genetic makeup of a subgroup, or population, of a species (Nowicki 10). Every living thing in the world is capable of evolving into something. Cells evolve to perform different tasks and to become stronger. Charles Darwin is the founder of evolution, he realized that species change over time to ensure survival. The future of evolution can not be predicted. Everything in our universe starts out as a single celled organism. All life traces back to three billionRead MoreEssay on human evolution1305 Words   |  6 PagesThe central purpose of this essay is to critically discuss the importance of understanding human evolution and the history of psychology for the modern psychologist. For the human evolution, the essay will be addressing on how we and other species descended from our ancestors and how the different environment has helped to us to become more adaptable. Regarding the history of psychology, the essay will be discussing on how psychology branched off from the philosophy approach to become its own science

Cellular Communication free essay sample

The basic structure of mobile networks includes telephone systems and radio services. Where mobile radio service operates in a closed network and has no access to the telephone system, mobile telephone service allows interconnection to the telephone network. Cell phones, also known as mobile phones or wireless phones, are hand-held phones with built-in antennas. Unlike home phones, cell phones can be carried from place to place with a minimum of fuss. This makes them a good choice for people who want to be in touch with other people even when they are away from the house. How Do Cell Phones Work? Not many people know it, but cell phones are actually two-way radios, much like the walkie-talkies of the past, albeit much more advanced. When you talk into your cell phone receiver, it registers your voice and converts the sound into radio waves. These waves travel through the air until they reach a receiver, which is usually found at a base station. This station will then send your call through a telephone network until it contacts the person you wish to speak with. Similarly, when someone places a call to your cell phone, the signal travels through the telephone network until it reaches a station near you. The station sends the radio waves out into the neighboring areas. These radio waves are then picked up by your cell phone and converted into the sound of a human voice. Cell phones are a vast improvement over the telecommunications technology of the past, and are daily becoming a fixture of modern life. As always, communication is vital, and cell phones will help you to better communicate with the key people in your life. Using a cell phone is one of the first steps you must take to participate effectively in the emerging global economy. Early Mobile Telephone System Architecture Traditional mobile service was structured in a fashion similar to television broadcasting: One very powerful transmitter located at the highest spot in an area would broadcast in a radius of up to 50 kilometres. The cellular concept structured the mobile telephone network in a different way. Instead of using one powerful transmitter, many low-power transmitters were placed throughout a coverage area. For example, by dividing a metropolitan region into one hundred different areas (cells) with low-power transmitters using 12 conversations (channels) each, the system capacity theoretically could be increased from 12 conversations or voice channels using one powerful transmitter to 1,200 conversations (channels) using one hundred low-power transmitters. Figure 2 shows a metropolitan area configured as a traditional mobile telephone network with one high-power transmitter. 2. 0 Mobile Telephone System Using the Cellular Concept Interference problems caused by mobile units using the same channel in adjacent areas proved that all channels could not be reused in every cell. Areas had to be skipped before the same channel could be reused. Even though this affected the efficiency of the original concept, frequency reuse was still a viable solution to the problems of mobile telephony systems. Engineers discovered that the interference effects were not due to the distance between areas, but to the ratio of the distance between areas to the transmitter power (radius) of the areas. By reducing the radius of an area by 50 per cent, service providers could increase the number of potential customers in an area fourfold. Systems based on areas with a one-kilometre radius would have one hundred times more channels than systems with areas 10 kilometres in radius. Speculation led to the conclusion that by reducing the radius of areas to a few hundred meters, millions of calls could be served. The cellular concept employs variable low-power levels, which allow cells to be sized according to the subscriber density and demand of a given area. As the population grows, cells can be added to accommodate that growth. Frequencies used in one cell cluster can be reused in other cells. Conversations can be handed off from cell to cell to maintain constant phone service as the user moves between cells. The cellular radio equipment (base station) can communicate with mobiles as long as they are within range. Radio energy dissipates over distance, so the mobiles must be within the operating range of the base station. Like the early mobile radio system, the base station communicates with mobiles via a channel. The channel is made of two frequencies, one for transmitting to the base station and one to receive information from the base station. 3. 0 Cellular System Architecture Increases in demand and the poor quality of existing service led mobile service providers to research ways to improve the quality of service and to support more users in their systems. Because the amount of frequency spectrum available for mobile cellular use was limited, efficient use of the required frequencies was needed for mobile cellular coverage. In modern cellular telephony, rural and urban regions are divided into areas according to specific provisioning guidelines. Deployment parameters, such as amount of cell-splitting and cell sizes, are determined by engineers experienced in cellular system architecture. Provisioning for each region is planned according to an engineering plan that includes cells, clusters, frequency reuse, and handovers. Cells A cell is the basic geographic unit of a cellular system. The term cellular comes from the honeycomb shape of the areas into which a coverage region is divided. Cells are base stations transmitting over small geographic areas that are represented as hexagons. Each cell size varies depending on the landscape. Because of constraints imposed by natural terrain and man-made structures, the true shape of cells is not a perfect hexagon. Clusters A cluster is a group of cells. No channels are reused within a cluster. Figure 4 illustrates a seven-cell cluster. Frequency Reuse Because only a small number of radio channel frequencies were available for mobile systems, engineers had to find a way to reuse radio channels to carry more than one conversation at a time. The solution the industry adopted was called frequency planning or frequency reuse. Frequency reuse was implemented by restructuring the mobile telephone system architecture into the cellular concept. The concept of frequency reuse is based on assigning to each cell a group of radio channels used within a small geographic area. Cells are assigned a group of channels that is completely different from neighbouring cells. The coverage area of cells is called the footprint. This footprint is limited by a boundary so that the same group of channels can be used in different cells that are far enough away from each other so that their frequencies do not interfere. Cells with the same number have the same set of frequencies. Here, because the number of available frequencies is 7, the frequency reuse factor is 1/7. That is, each cell is using 1/7 of available cellular channels. Cell Splitting Unfortunately, economic considerations made the concept of creating full systems with many small areas impractical. To overcome this difficulty, system operators developed the idea of cell splitting. As a service area becomes full of users, this approach is used to split a single area into smaller ones. In this way, urban centres can be split into as many areas as necessary to provide acceptable service levels in heavy-traffic regions, while larger, less expensive cells can be used to cover remote rural regions. Handoff The final obstacle in the development of the cellular network involved the problem created when a mobile subscriber travelled from one cell to another during a call. As adjacent areas do not use the same radio channels, a call must either be dropped or transferred from one radio channel to another when a user crosses the line between adjacent cells. Because dropping the call is unacceptable, the process of handoff was created. Handoff occurs when the mobile telephone network automatically transfers a call from radio channel to radio channel as mobile crosses adjacent cells. During a call, two parties are on one voice channel. When the mobile unit moves out of the coverage area of a given cell site, the reception becomes weak. At this point, the cell site in use requests a handoff. The system switches the call to a stronger-frequency channel in a new site without interrupting the call or alerting the user. The call continues as long as the user is talking, and the user does not notice the handoff at all. 4. 0 North American Analog Cellular Systems Originally devised in the late 1970s to early 1980s, analog systems have been revised somewhat since that time and operate in the 800-MHz range. A group of government, telco, and equipment manufacturers worked together as a committee to develop a set of rules (protocols) that govern how cellular subscriber units (mobiles) communicate with the cellular system. System development takes into consideration many different, and often opposing, requirements for the system, and often a compromise between conflicting requirements results. Cellular development involves the following basic topics: * frequency and channel assignments * type of radio modulation * maximum power levels * modulation parameters * messaging protocols * call-processing sequences The Advanced Mobile Phone Service (AMPS) AMPS was released in 1983 using the 800-MHz to 900-MHz frequency band and the 30-kHz bandwidth for each channel as a fully automated mobile telephone service. It was the first standardized cellular service in the world and is currently the most widely used standard for cellular communications. Designed for use in cities, AMPS later expanded to rural areas. It maximized the cellular concept of frequency reuse by reducing radio power output. The AMPS telephones (or handsets) have the familiar telephone-style user interface and are compatible with any AMPS base station. This makes mobility between service providers (roaming) simpler for subscribers. Limitations associated with AMPS include the following: * low calling capacity * limited spectrum no room for spectrum growth * poor data communications * minimal privacy * inadequate fraud protection AMPS is used throughout the world and is particularly popular in the United States, South America, China, and Australia. AMPS uses frequency modulation (FM) for radio transmission. In the United States, transmissions from mobile to cell site use separate frequencies from the base station to the mobil e subscriber. Narrowband Analog Mobile Phone Service (NAMPS) Since analog cellular was developed, systems have been implemented extensively throughout the world as first-generation cellular technology. In the second generation of analog cellular systems, NAMPS was designed to solve the problem of low calling capacity. NAMPS is now operational in 35 U. S. and overseas markets, and NAMPS was introduced as an interim solution to capacity problems. NAMPS is a U. S. cellular radio system that combines existing voice processing with digital signaling, tripling the capacity of todays AMPS systems. The NAMPS concept uses frequency division to get 3 channels in the AMPS 30-kHz single channel bandwidth. NAMPS provides 3 users in an AMPS channel by dividing the 30-kHz AMPS bandwidth into 3 10-kHz channels. This increases the possibility of interference because channel bandwidth is reduced. 5. 0 Cellular System Components The cellular system offers mobile and portable telephone stations the same service provided fixed stations over conventional wired loops. It has the capacity to serve tens of thousands of subscribers in a major metropolitan area. The cellular communications system consists of the following four major components that work together to provide mobile service to subscribers. * public switched telephone network (PSTN) * mobile telephone switching office (MTSO) cell site with antenna system * mobile subscriber unit (MSU) PSTN The PSTN is made up of local networks, the exchange area networks, and the long-haul network that interconnect telephones and other communication devices on a worldwide basis. Mobile Telephone Switching Office (MTSO) The MTSO is the central office for mobile switching. It houses the mobile switching center (MSC), field monitoring, and relay stations for switching calls from cell sites to wireline central offices (PSTN). In analog cellular networks, the MSC controls the system operation. The MSC controls calls, tracks billing information, and locates cellular subscribers. The Cell Site The term cell site is used to refer to the physical location of radio equipment that provides coverage within a cell. A list of hardware located at a cell site includes power sources, interface equipment, radio frequency transmitters and receivers, and antenna systems. Mobile Subscriber Units (MSUs) The mobile subscriber unit consists of a control unit and a transceiver that transmits and receives radio transmissions to and from a cell site. The following three types of MSUs are available: * the mobile telephone (typical transmit power is 4. 0 watts) * the portable (typical transmit power is 0. 6 watts) * the transportable (typical transmit power is 1. 6 watts) * The mobile telephone is installed in the trunk of a car, and the handset is installed in a convenient location to the driver. Portable and transportable telephones are hand-held and can be used anywhere. The use of portable and transportable telephones is limited to the charge life of the internal battery. 6. 0 Digital Systems As demand for mobile telephone service has increased, service providers found that basic engineering assumptions borrowed from wire line (landline) networks did not hold true in mobile systems. While the average landline phone call lasts at least 10 minutes, mobile calls usually run 90 seconds. Engineers who expected to assign 50 or more mobile phones to the same radio channel found that by doing so they increased the probability that a user would not get dial tone this is known as call-blocking probability. As a consequence, the early systems quickly became saturated, and the quality of service decreased rapidly. The critical problem was capacity. The general characteristics of time division multiple access (TDMA), Global System for Mobile Communications (GSM), personal communications service (PCS) 1900, and code division multiple access (CDMA) promise to significantly increase the efficiency of cellular telephone systems to allow a greater number of simultaneous conversations. Figure 8 shows the components of a typical digital cellular system. The advantages of digital cellular technologies over analog cellular networks include increased capacity and security. Technology options such as TDMA and CDMA offer more channels in the same analog cellular bandwidth and encrypted voice and data. Because of the enormous amount of money that service providers have invested in AMPS hardware and software, providers look for a migration from AMPS to digital analog mobile phone service (DAMPS) by overlaying their existing networks with TDMA architectures. Time Division Multiple Access (TDMA) North American digital cellular (NADC) is called DAMPS and TDMA. Because AMPS preceded digital cellular systems, DAMPS uses the same setup protocols as analog AMPS. TDMA has the following characteristics: * IS? 54 standard specifies traffic on digital voice channels * initial implementation triples the calling capacity of AMPS systems * capacity improvements of 6 to 15 times that of AMPS are possible * many blocks of spectrum in 800 MHz and 1900 MHz are used * all transmissions are digital * TDMA/FDMA application 7. 3 callers per radio carrier (6 callers on half rate later), providing 3 times the AMPS capacity TDMA is one of several technologies used in wireless communications. TDMA provides each call with time slots so that several calls can occupy one bandwidth. Each caller is assigned a specific time slot. In some cellular systems, digital packets of information are sent during each time slot and reassembled by the receiving equipment into the original voice components. TDMA uses the same frequency band and channel allocations as AMPS. Like NAMPS, TDMA provides three to six time channels in the same bandwidth as a single AMPS channel. Unlike NAMPS, digital systems have the means to compress the spectrum used to transmit voice information by compressing idle time and redundancy of normal speech. TDMA is the digital standard and has 30-kHz bandwidth. Using digital voice encoders, TDMA is able to use up to six channels in the same bandwidth where AMPS uses one channel. Extended Time Division Multiple Access (E? TDMA) The E? TDMA standard claims a capacity of fifteen times that of analogue cellular systems. This capacity is achieved by compressing quiet time during conversations. E? TDMA divides the finite number of cellular frequencies into more time slots than TDMA. This allows the system to support more simultaneous cellular calls. Fixed Wireless Access (FWA) FWA is a radio-based local exchange service in which telephone service is provided by common carriers (see Figure 9). It is primarily a rural application that is, it reduces the cost of conventional wire line. FWA extends telephone service to rural areas by replacing a wire line local loop with radio communications. Other labels for wireless access include fixed loop, fixed radio access, wireless telephony, radio loop, fixed wireless, radio access, and Ionic. FWA systems employ TDMA or CDMA access technologies. Personal Communications Service (PCS) The future of telecommunications includes PCS. PCS at 1900 MHz (PCS 1900) is the North American implementation of digital cellular system (DCS) 1800 (GSM). Trial networks were operational in the United States by 1993, and in 1994 the Federal Communications Commission (FCC) began spectrum auctions. As of 1995, the FCC auctioned commercial licenses. In the PCS frequency spectrum, the operators authorized frequency block contains a definite number of channels. The frequency plan assigns specific channels to specific cells, following a reuse pattern that restarts with each nth cell. The uplink and downlink bands are paired mirror images. As with AMPS, a channel number implies one uplink and one downlink frequency (e. g. , Channel 512 = 1850. -MHz uplink paired with 1930. 2-MHz downlink). Code Division Multiple Access (CDMA) CDMA is a digital air interface standard, claiming 8 to 15 times the capacity of analogue. It employs a commercial adaptation of military, spread-spectrum, single-sideband technology. Based on spread spectrum theory, it is essentially the same as wire line service the primary difference is that access to the local exchan ge carrier (LEC) is provided via wireless phone. Because users are isolated by code, they can share the same carrier frequency, eliminating the frequency reuse problem encountered in AMPS and DAMPS. Every CDMA cell site can use the same 1. 25-MHz band, so with respect to clusters, n = 1. This greatly simplifies frequency planning in a fully CDMA environment. CDMA is an interference-limited system. Unlike AMPS/TDMA, CDMA has a soft capacity limit; however, each user is a noise source on the shared channel and the noise contributed by users accumulates. This creates a practical limit to how many users a system will sustain. Mobiles that transmit excessive power increase interference to other mobiles. For CDMA, precise power control of mobiles is critical in maximizing the systems capacity and increasing battery life of the mobiles. The goal is to keep each mobile at the absolute minimum power level that is necessary to ensure acceptable service quality. Ideally, the power received at the base station from each mobile should be the same (minimum signal to interference). 7. 0 REFERENCES 1. Basic Communication Engineering by Rusnani Arifin, Juliana Md Sharif, Nor Hidayah Saad and Mohd Aminuddin Murad. 2. http://www. gsmfavorites. com/documents/introduction/gsm/ 3. en. wikipedia. org/wiki/History_of_mobile_phones