【正文】 and many other new features, such as AlwaysOn capabilities. ? Operate on 900/1800/1900MHz. Provide theoretical data transfer rate 115 Kbps (Pratical rate is around 40 Kbps). ? Upgrade on existing works, so it is a safe point between 2G and 3G. ? New packetswitched core work ? Software upgrades only in radio access work work protocols 65 ? CDMA2022 1x ? Officially classified to 3G by ITU (Int’l Tele. Union). But it does not meet the minimum speed requirements for 3G, and very similar to GPRS, so it is a technology in practice. ? Each channel is MHz. Theoretical data transfer rate is 144 Kbps (Practical rate is 40~56 Kbps). ? Compatible with cdmaOne, but the capacity is double, and also provide AlwaysOn capabilities. work protocols 66 (Cont’d) ? devices ? Often it is the device that limits the total data rates that works provide. ? Most devices do not provide the needed capability due to cost reasons. ? GPRS provide three classes of handsets / terminals: ? Class A: handle both voice and packet data at the same time ? Class B: handle both voice and packet data, but not at the same time ? Class C: handle either voice or data 67 (Cont’d) ? Applications ? Wireless Inter applications with full graphics and some multimedia capabilities ? Corporate , calendar, contact lists ? Instant messaging ? Still and moving images ? Job dispatch ? Vehicle positioning using locationbased services ? Remote LAN access ? File sharing applications 68 ThirdGeneration work (3G) ? Original motivation/goal is to develop a single global standard for high speed data and high quality voice services. ? Have all users worldwide use a single standard that would allow for true global roaming. ? Unfortunately, panies and standards bodies from Europe, North America, and Japan could not agree on a single protocol for 3G. After much negotiation, it was realized that a single 3G implementation is impossible. ? This is because backward patibility with 2G works and frequency differences among countries were too difficult to overe 69 3G (Cont’d) ? 3G works’ features ? Based on CDMA and IP technologies. ? Higher data rates: ranging from 144 Kbps to 2M bps, depending on the level of mobility: ? High mobility (speed = 120 KM per hour) 144Kbps ? Full mobility (speed 120 KM per hour) 384Kbps ? Limited mobility (speed 10 KM per hour) 2Mbps Data transfer rates also depend on user’s distance from base station ? Enhanced quality of services: QoS is supported from end to end. ? Allow users to establish agreements with work operators for certain properties such as data transfer rate and work latency. 70 3G (Cont’d) ? 3G works’ features (cont’d) ? Global seamless operation in multicell environment (SAT, macro, micro, pico) ? Global roaming: multimode, multiband, lowcost terminal, portable services amp。 QoS. 71 3G (Cont’d) ? 3G Devices ? Support for multimedia ? Large, highresolution screens ? Form factors similar to PDAs ? Integrated voice and data ? Mobile operating systems that allow for sophisticated clientside applications 72 3G (Cont’d) ? 3G Applications: in addition to those similar to applications, we have new ones: ? Streaming video applications ? Downloadable audio such as MP3s ? Overtheair download of software programs ? Workplace collaboration ? VoiceoverIP ? Locationbased services ? Multimedia messaging services ? Corporate and a full range of attachments 73 3G work protocols ? Three branches of 3G systems were created: ? EDGE (Enhanced Data Rates for Global Evolution) ? CDMA2022 1x EV ? WCDMA (referred as UMTS in Europe) All are based on CDMA except EDGE (TDMA) ? In 1999, ITU approved an industry standard for 3G, called Int’l Mobile (IMT 2022) ? With the goal to converge the three 3G standards into a single universally accepted standard. TDSCDMA 74 ? EDGE ? Allow current GSM works to offer 3G within existing frequencies. ? TDMA or GSM/GPRS can be upgraded to EDGE with minimum impact. ? Use narrowband technology, no need to obtain a 3G license. These make it a lowcost, fast solution. ? Peak data rate: 384K bps, download rate: 75~150 Kbps. ? Provide a seamless upgrade from 2G to 3G. 3G work protocols 75 ? CDMA2022 1x EV: two members of the family: ? CDMA2022 1x Evolution Data Optimized (CDMA2022 1x EVDO) ? Provide Mbps peak data transfer rate. Support the plete range of available frequencies. Work on all IP works. ? CDMA2022 1x Evolution Data and Voice (CDMA2022 1x EVDV) ? Provide similar wireless data capabilities as CDMA2022 1x EVDO, but with additional voice capabilities. The peak data transfer rate will be 3 Mbps. 3G work protocols 76 ? WCDMA ? Require 5MHz channel bandwidth. ? Can provide 3 modes of mobility defined by IMT2022 (144 Kbps, 384 Kbps, 2M bps) ? Unlike the upgrade to GPRS and EDGE, WCDMA requires coverage to be built from scratch. This requires significant capital expenditures by carriers. ? Fortunately, WCDMA is patible with GSM/GPRS/EDGE, so user can roam between them. 3G work protocols 77 CDMA發(fā)展歷程 78 Evolution to 3G ? First 3G systems were implemented on a trial basis in Japan and Europe in late 2022. ? Worldwide mercial rollouts began in late 2022 and will continue into 2022. ? In HK, 3G was launched in early 2022. 79 Comparison of work protocols. 協(xié)議 頻率 數(shù)據(jù)傳輸率 應(yīng)用地區(qū) Mobitex 400 MHz, 800 MHz 900 MHz 8 kbps Widely available in North America。 Coverage in 23 other countries CDPD 800 – 900 MHz kbps Widely available in North America DataTAC 800 MHz kbps North America, Asia Pacific, and Europe 80 Comparison of work protocols 協(xié)議 頻率 數(shù)據(jù)傳輸率 應(yīng)用地區(qū) TDMA 800 MHz, 1900 MHz kbps via CDPD Widely used in