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Chapter 7

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Department
Administrative Studies
Course
ADMS 2511
Professor
Cristobal Sanchez- Rodriguez
Semester
Fall

Description
Chapter 7 - RFID technology allows manufacturers to attach tags with antennas and computer chips on goods and then track their movement through radio signals - when Gillette was preparing to launch a new 5 bladed razor called Fusion, it looked very carefully at how it could benefit from RFID for the products debut - the company used RFID to track the pallets, cases and displays in order to test the display compliance that is whether stores were setting up displays on time and according to directions – at just two of its retail partners - Wireless: term that is used to describe telecommunications in which electromagnetic waves, rather than some form of wire or cable carry the signal between communicating devices - the opening case is an example of the use of a wireless technology (RFID) that provided valuable information about a problem between P&G and its retailers - this same problem can be applied to any company with supply chain for example Walmart and Loblaws - the case also demonstrates that wireless technology is in its beginning stages with exciting potential but currently high costs - Mobile computing: refers to real time, wireless connection between a mobile device and other computing environments such as the internet or an intranet - Mobile commerce also known as m commerce refers to e commerece transactions that are conducted in a wireless environment, especially via the internet - Pervasive computing: also called ubiquitous computing means that virtually every object has processing power with wireless or wired connections to a global network Wireless Technologies - include both wireless devices, such as smart phones, and wireless transmission media such as microwave, satellite, and radio - these technologies are fundamentally changing the ways organizations operate and do business Wireless Devices - they make productive use of time that was formerly wasted (example, while commuting to work on public transportation) - also they can take these devices with them, their work locations are becoming more flexible - next, wireless technology enables them to allocate their working time around personal and professional obligations - The Wireless Application Protocol (WAP): is the standard that enables wireless devices to access web based information and services - WAP compliant devices contain microbrowsers, which are internet browsers with a small file size that can work within the confines of small screen sizes on wireless devices and the relatively low bandwidths of wireless networks - as wireless devices become increasingly powerful, the trend is for these devices to have browsers with more functionality - for example the Apple Iphone runs the Safari browser - wireless devices are small enough to easily carry or wear, have sufficient computing power to perform productive tasks, and can communicate wirelessly with the internet and other devices - for example pagers, email hand helds, personal digital assistants (PDAs), cell phones - new devices now, called the smart phones combine the functions of these devices, and the capabilities of these new devices include cellular telephone, Bluetooth, Wi-Fi, digital camaras, Global positioning systems (GPS), organizers, schedulars, address book, calculators, access to email and short message servie (sending and receiving short text messages up to 160 characters in length), instant messaging, MP3 music players, video players, internet access with a full function browser, and QWERTY keyboards - for example the apple iphone, blackberry 8800, sony mylo, Motorola V3T etc - one downside of smart phones is that people can use them to copy and pass on confidential information - example iceberg systems provides technology that deactivates the imaging systems in camera phones after they enter specific locations Wireless Transmission Media - wireless media, or broadcast media, transmit signals without wires over the air or in space - major types of wireless media are microwave, satellite radio, and infrared Microwave - microwave transmission systems: widely used for high volume, long distance, line of sight communication - line of sight means that the transmitter and receiver are in view of each other - the requirement for adjacent microwave towers to be in view of each other creates problems because the earths surface is curved - for this reason, microwave towers usually can not be spaced more than about 48 km’s apart - therefore this limits the usefulness of microwave transmissions as a solution to data communications needs, especially over very long distances - also they are susceptible to environmental interference during severe weather such as heavy rain, snow storms Satellite - satellite transmission systems: make use of communication satellites - three types of satellites around the earth: geostationary earth orbit (GEO), medium earth orbit (MEO) and low earth orbit (LEO), GEO being farthest from the earth and LEO the closest - as with microwave transmission, satellites must receive and transmit data via line of sight - however the enormous footprint – the area of the earth’s surface reached by a satellites transmission overcomes the limitations of microwave data relay stations - most basic rule is the high a satellite orbits, the larger its footprints - therefore middle earth orbit satellites have a smaller foot print than geostationary satellites and low earth orbit satellites have the smallest foot print - in contrast to line of sight transmission with microwave, satellites use broadcast transmission, sending signals to many receivers at one time - so even though satellites are line of sight like microwave, they are high enough for broadcast transmission, thus overcoming the limitations of microwave Types of Orbits GEO: satellites orbit 35, 888 km’s directly above the equator - maintain a fixed position above the earths surface because at their altitude their orbital period matches the 24 hour rotational period of the earth - for this reason, receivers on the earth do not have to track GEO satellites - GEO satellites are excellent for sending television programs to cable operators and broadcasting directly to homes - one major limitation is that their transmissions take a quarter of a second to send and return - this brief pause, called Propagation Delay, makes two way telephone conversations difficult - also GEO are large, expensive and require large amounts of power to launch MEO: located about 9656 km’s above the earth’s surface - MEO orbits require more satellites to cover the earth than GEO orbits because MEO footprints are smaller - two advantages over GEO: they are less expensive and they do not have an appreciable propagation delay - however, because MEO satellites move with respect to a point on the earths surface, receivers must track these satellites LEO: located 644 to 1127 km’s above the earths surface - since LEO’s are much closer to earth, they have little if any propagation delay - like MEO, however, LEO satellites move with respect to a point on the earth’s surface therefore must be tracked by receivers - tracking LEO satellites ism ore difficult than tracking MEO since LEO move much more quickly than MEO relative to a point on the earth - unlike GEO and MEO satellites, LEO can pick up signals from weak transmitters - this is important because handheld telephones that operate via LEO satellites need less power and can use smaller batteries - Another advantage: they consume less power and cost less to launch than GEO and MEO satellites - footprint of LEO is small, which means that many of them are required to cover the earth - for this reason a single organization often produces multiple LEO satellites known as LEO constellations - two examples are Iridium and globalstar Type Characterisitcs Orbit # (in orbit) Use GEO - satellites remain stationary relative to a point on earth 35, 888 km 8 TV signals - few satellites are needed for global coverage - Transmission delay (approx .25 sec) - most expensive to build and launch - longest orbital life (many years) MEO - satellites move relative to a point on earth 10, 354 km 10-12 GPSs - moderate number needed for global coverage - requires medium powered transmitters - negligible transmission delay - less expensive to build and launch - moderate orbital life (6 – 12 years) LEO - satellites move rapidly relative to a point on earth 643 – 1126 km Many Telephones - large number needed for global coverage - requires only low power transmitters - negligible transmission delay - least expensive to build and launch - shortest orbital life (as low as 5 years) Global Positioning System: - is a wireless system that uses satellites to enable users to determine their position anywhere on the earth - GPS is supported by 24 satellites that are shared worldwide - as of mid 2007, the only GPS called NAV STAR GPS is owned and operated by the US department of defense - the exact position of each satellite is always known because the satellite continuously broadcasts its position along with a time signal - by using the known speed of the signals and the distance from three satellites or 4 satellites it is possible to find the location of any receiving station or user within a range of about 3 metres - GPS software can also convert the user’s latitude and longitude to an electronic map - commercial use of GPS has become widespread, including for navigation, mapping, and surveying, particularly in remote areas - cell phones in Canada and united states must have GPS embedded in them so that the location of a person making an emergency call can be tracked Internet over Satellite (IOS) - in many regions of the world, IoS is the only option available for internet connections because installing the necessary cables is either too expensive or is physically impossible - IoS allows the user to access the internet via GEO satellites from a dish mounted on the side of their home - although IoS makes the internet available to many people who otherwise could not access it, it has its drawbacks - as we have seen, GEO satellite transmissions entail a propagation delay, and they can be disrupted by environmental influences such as thunderstorms Radio - Radio transmission uses radio wave frequencies to send data directly between transmitters and receivers - Advantages: radio waves travel easily through normal office walls, fairly inexpensive and easy to install, radio waves can transmit data at high speeds - for these reason, radio is increasingly being used to connect computers to both peripheral equipment and local area networks - Drawbacks: radio media can create electrical interference problems, radio transmissions are susceptible to snooping by anyone who has similar equipment that operates on the same frequency Satellite Radio - one problem with radio transmission is that when you travel too far away from the source station, the signal breaks up and fades into static - Satellite radio however, overcomes this problem since it offers uninterrupted, near CD quality music that is beamed to your radio either at home or in your car, from space - in addition it offers a broad spectrum of stations, types of music, news and talk - XM Canada subsidiary of XM satellite radio, Sirius Canada subsidiary of Sirius Satellite radio are competitors that launched satellite radio services - XM broadcasts its signals from GEO satellites and Sirius uses MEO satellites - listeners subscribe to the service for a monthly fee Infrared - infrared light is red light that is not commonly visible to human eyes - common applications of infrared light are in remote control units for TV’s, VCR’s, DVD’s and CD players - in addition, like radio transmission, infrared transceivers are used for short distance connections between computers and peripheral equipment and local area networks - a Transceiver: device that can transmit and receive signals - many portable PC’s have infrared ports which are handy when cable connections with peripheral (such as printer or modem) are not practical Wireless Computer Networks and Internet Access Short Range Wireless Networks - simplify the task of connecting one device to another, eliminating wires and enabling users to move around while they use the devices - have a range of 300 m or less - discuss Bluetooth, ultra wideband (UWB), and Near Field Communications (NFC) Bluetooth - an industry specification used to create small personal area networks - Personal Area Network: computer network used for communication among computer devices (for example, telephones, personal digital assistants, and smart phones) close to one person - Bluetooth can link up to 8 devices within 10 m area using low power, radio based communication - it can transmit up to 2.1 Mbps (megabits per second) - common applications for Bluetooth are wireless handsets for cell phones and portable music players - Advantages: low power consumption, uses omni directional radio waves : means that you do not have to point one Bluetooth device at another for a connection to occur - lego toys use Bluetooth page 213 Ultra Wideband - UWB is a high bandwidth wireless technology with transmission speeds in excess of 100 Mbps - a good choice for applications such as streaming multimedia from say a personal computer to a television Near Field Communications - NFC has the smallest range of any short range wireless networks - designed to be embedded in mobile devices such as cell phones and credit cards - using NFC you can swipe your device or card within a few cm’s of point of sale terminals to pay for items Medium Range Wireless Networks - are the familiar wireless local area networks (WLANs) - most common is wireless fidelity or Wi-Fi Wireless Fidelity (Wi-Fi) - is a medium range, wireless local area network (WLAN) which is like a wired LAN but without the cables - in a typical configuration, a transmitter with an antenna, called a wireless access point, connects to a wired LAN or to satellite dishes that provide an internet connection - a wireless access point provides service to a number of users within a small geographical perimeter (up to about 70 m) known as a hotspot - to support a larger number of users across a larger geographical area, several wireless access points are needed - to communicate wirelessly, mobile devices, such as laptop PCs’ typically have built in wireless network interface card (NIC) - WiFi provides fast and easy internet or intranet broadband access from public hotspots located at airports, hotels, internet cafes, universities, conference centers, offices and homes. - broadband means high bandwidth - users can access the interney while walking across the campus, to their office or through out their home - users can access Wi Fi with their laptops, desktops or PDA’s by adding a wireless network card, which most manufacturers are incorporating in their PC’s - the Institute of Electrical and Electronics Engineers (IEEE) has established a set of standards for wireless computer networks - The IEEE standard for Wi – Fi is the 802.11 family, there are 4 standards in this family, 802.11a, 802.11b, 802.11g, and 802.11n - today most WLANs use the 802.11g standard which can transmit up to 54 Mbps and has a range of about 90 m. - 802.11n standard was still under development as of mid 2007, this standard is designed to have wireless transmission speeds between 250 and 300 Mbps and a range double that of 802.11g or some 180m - Benefits: Wi-Fi low cost and ability to provide simple internet access - greatest facilitator of the wireless internet, that is the ability to connect to the internet wirelessly - laptop PC’s are equipped with chips that can send and receive Wi-Fi signals - coporations like McDOnalds, Starbucks, Chapters are offering customer wi fi in many of their stores, mainly for internet access since their strategy is to encourage customers to spend more time in their stores and to choose their stores over those of competitors - Drawbacks: three factors preventing the commercial Wi-Fi market from expanding even further: roaming, security and cost - at this time users can not roam from hotspot to hotspot if the hotspots use different Wi-Fi network services - some hotspots offer free service while other charge a fee - Security: since Wi-Fi uses radio waves it is difficult to shield from intruders - final limitation is cost: even though Wi-Fi services are relatively inexpensive, many experts question whether commercial Wi-Fi services can survive when so many free hotspots are available to users - for example city of Toronto implemented a downtown wireless network that was free for the first few months, once they started charging, many subscribers dropped off the service - in some places, Wi-Fi internet hubs are marked by symbols on sidewalks and walls, this practice is called war chalking - where the symbols tell you that wi fi is available in the building, while others tell that they are restricted Wireless Mesh Networks - Mesh networks: use multiple Wi-Fi access points to create a wide area network that can be as large as, for instance, the 350 sq km network being developed in Philadelphia, U.S.A - they are a series of interconnected local area networks Wide Area Wireless Networks - connect users to the internet over geographically dispersed territory - these networks typically operate over the licensed spectrum - use portions of the wireless spectrum that are regulated by the government - in contrast, Bluetooth and Wi-Fi operate over the unlicensed spectrum and are therefore more prone to interference and security problems - in general, wide area wireless network technologies fall into two categories: cellular radio and wireless broadband Cellular Radio - cellular telephones use radio waves to provide two way communication - cell phone communicates with radio antennas (towers) placed within adjacent geographic areas called cells - telephone message is transmitted to the local cell (antenna) by the cell phone and then is passed from cell to cell until it reaches the cell of its destination - at this final cell, the message is either transmitted to the receiving cell phone or is transferred to the public switched telephone system to be transmitted to a wire line telephone - this is why you can use a cell phone to call both other cell phones and standard wire line phones - first generation (1G) cellular used analogue signals and had low bandwidth (capacity) - second generation (2G) uses digital signals primarily for voice communication, it provides data communication up to 10 Kbps - 2.5 G uses digital signals and provides voice and data communication up to 144 Kbps - Third Generation (3G) uses digital signals and can transmit voice and data up to 384 Kbps when the device is moving at a walking pace, 128 Kbps when movig in a car and up to 2 Mbps when the device is in a fixed location - 3G supports video, web browsing and instant messaging - fourth generation (4G) is still under development and is not one defined technology or standard - the wireless world forum defines 4G as a network that operates with internet technology, combines this technology with other applications and technologies such Wi-Fi and WiMax and operates at speeds ranging from 100 Mbps in cell phone networks to one Gbps in local Wi-Fi networks - third generation disadvantages: - cellular companies in North America use two separate technologies: Code division multiple Access (CDMA) and G
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