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Welcome to ZTE University!. 2004.2.10. Class Rules. Class Hours: 8:40 AM - 11:50 AM 14:10-17:20 PM Little Breaks: Several short breaks throughout class Turn down ringers on mobile phones. No smoking in classroom.
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Welcome to ZTE University! 2004.2.10
Class Rules • Class Hours: 8:40 AM - 11:50 AM • 14:10-17:20 PM • Little Breaks: • Several short breaks throughout class • Turn down ringers on mobile phones. • No smoking in classroom
BSS Course Agenda Course 1: CDMA Foundation Theory Course 2: BSS Hardware Intruduction and Operation Course 3: PDSN Hardware Intrucduction and Operation Course 4: Network Planning and Optimization Basic
CDMA Overview CDMA Basic Principle CDMA Channel Structure and Modulation CDMA Key Technology Course 1CDMA Foundation Theory
CDMA Overview 2004.2.10
Upon completion of this lesson, the student will be able to master: -- the history of mobile communication -- the advantage of CDMA -- CDMA migration from 2G to 3G -- CDMA spectrum usage -- the role of ZTE in CDMA Objectives
Mobility: flexible and convenient,global personal communication Poor environment and conditions : Co-channel interference, multi-path(space and time)shadow effect and delay, power change and other noise MultipleMS and channels: Interference 、near and far effect Limit of frequency resources Reliability is important registration, handoff, switching Characteristics of Mobile Communication
Evolution of Mobile Communications System AMPS: Advanced Mobile Phone System TACS: Total Access Communication System GPRS: General Packet Radio Services
CDMA-Its History & Status • 1993, the first CDMA standard IS-95 was issued by Qualcomm(U.S.A); • In 1995, CDMA technologie was put into commercialization in Hongkong and America on large scale; • In 1997, CDMA trial networks were constructed in Beijing, Xi’an, Shanghai and Guangzhou in China; • In April, 2001, China Unicom began to construct CDMA networks—the largest in the world; • At present, CDMA commercial networks are established in about 40 countries or area, almost 20% of all users in the world.
AMPS, D-AMPS, N-AMPS 2 1 3 1 Users 3 7 1 6 4 5 Vulnerability: C/I @ 17 dB 30 30 10 kHz Typical Frequency Reuse N=7 GSM 2 Vulnerability: C/I @12-14 dB 1 8 Users 3 4 200 kHz Typical Frequency Reuse N=4 1 CDMA Vulnerability: Eb/No@6--7 dB 1 1 1 1 1 1 1 20 Users 1 1 1 1 1 1 1250 kHz Typical Frequency Reuse N=1 Advantages of CDMA Frequency reuse facto is 1; network design and expanding become much easier
Advantages of CDMA • large coverage • almost 2 times than GSM, save money for operator Example:cover 1000 km2: GSM need 200 BTS ,CDMA only need 50 BTS Attention: exact result need “Link Budget ”
FDMA Power Frequency Time TDMA Power Frequency Time CDMA Power Frequency Time Advantages of CDMA High spectrum capacity,8--10 times than AMPS,4—6 times than GSM FDMA---Different user use different frequncy TACS、AMPS TDMA---Different user use different time slot of one frequency GSM、DAMPS CDMA---Different user use same frequency at the same time,but with different spreading code
Advantages of CDMA • High privacy,hard to wiretapping Each user is below the noise deeply Spread signal Information signal Demodulated signal TX RX Spread code Spread code
Advantages of CDMA Use soft handoff, decrease drop-call rate • CDMA:”make before break”---soft handoff • Other systems: “make after break”---hard handoff
Voice quality (MOS) 8k CDMA 64k PCM 13k GSM 13k CDMA 8kEVRC CDMA Advantages of CDMA Good voice quality, use 8k,13K(QCELP,EVRC)voice coding—the best coding method in the world.
Advantages of CDMA Perfect Power Control and voice activation make the MS Power low, healthy for humanbody—green mobile phone. Mean Power Max Power GSM: 125mW 2W CDMA: 2mW 200mW
Advantages of CDMA Smooth migration to 3G and the operator’s benefit is protected at the most 95A 95B • Software update • Replace MS to get new service 95B 1X • Add 1X channel board • Software update • Replace MS to ge new service 1X 1XEV • Add 1XEV channel board • Software update • Replace MS to get new service • inexpesive Technical Scheme: Economic Scheme: • Almost free • inexpensive
Channel Numbers 1 1 991 333 334 666 667 716 717 799 991 333 334 666 667 716 717 799 1023 1023 A” A” A B A’ B’ other uses A B A’ B’ 1 10 10 1.5 2.5 1 10 10 1.5 2.5 824 MHz 849 MHz 869 MHz 894 MHz Reverse link (i.e., mobile transmits) Forward link (i.e., cell site transmits) Possible CDMA Center Freq. Assignments ~300 kHz. “guard bands” possibly required if adjacent-frequency signals are non-CDMA (AMPS, TDMA, ESMR, etc.) CDMA 800 MHz Cellular Spectrum Usage • All CDMA RF carriers are 1.25 MHz. wide • Can serve ~20 users /8 kb vocoder
Guard Bands Paired Bands Licensed Licensed Channel Numbers Unlicensed 1199 1199 299 300 400 699 700 800 900 299 300 400 699 700 800 900 0 0 B B B B B B T T T T T T Data Voice MTA MTA BTA MTA MTA BTA A A A A A A A D B E F C A D B E F C 15 5 15 5 5 15 10 10 15 5 15 5 5 15 1910 1930 1990 1850 MHz MHz MHz MHz Reverse link (i.e., mobile transmits) Forward link (i.e., cell site transmits) CDMA PCS 1900 MHz Spectrum Usage
1023 991 334 666 667 715 716 799 333 1 A” A Band B Band A’ B’ Channel Numbers 736 1019 37 78 119 160 201 242 283 384 425 466 507 548 589 630 691 777 8 7 6 5 4 3 2 1 1 2 3 4 5 6 7 9 9 8 * ** * *Requires frequency coordination with non-cellular interferers **Requires frequency coordination with A-band carrier CDMA A-Band Carriers CDMA B-Band Carriers A Band Primary Channel 283 A Band Secondary Channel 691 B Band Primary Channel 384 B Band Secondary Channel 777 CDMA Frequency ChannelAssignment at 800 MHz Cellular • IS-95 Recommends to Start CDMA Deployment with Either the Primary or the Secondary Channel
ZTE’s Activities in CDMA • In 1995, CDMA mobile telecommunication project was started • In November, 1999, ZTE signed the “Agreement on CDMA R&D” with Qualcomm • In August, 2000, the first field trial was set up. • In September, 2000, ZTE presented the first CDMA handset with UIM in the world. • In January, 2001, the first cdma2000-1x call was passed through in lab • In March, 2001, ZTE cdma2000-1x realized the integrated transmission of voice, data & image.The data rate reach up to 153.6Kbps. • The certificates acquired: • CDMA 800M ZXC10-MSC/VLR, • HLR/AUC,BSC, BTS network access licenses • CDMA 800M/1.9G ZXC10-BTS type approval certificates
PSTN/PLMN MSC/VLR HLR/AUC Abis E1 BTS(IS-95) Um IS95 SC BSC(IS-95) Abis BTS(IS-95) WIN IP HA Um IS2000 Abis BSC/ PCF (1X) OMC E1 Internet E1 STM-1 2G/3G 终端 BTS(1X) Ethernet 路由器 路由器 IP Abis Ethernet BSC/ PCF (1X) PDSN/FA E1 STM-1 AAA BTS(1X) 业务服务器 ZTEA Famous CDMA Brand