Transcript ECE4730_L27 - University of Missouri

Cellular Standards
Advanced Mobile Phone Service (AMPS) – 1G
Analog FM
 IS-136 (aka USDC, IS-54) – 2G Digital TDMA
 Global System for Mobile (GSM) – 2G Digital TDMA

 European

IS-95 CDMA – 2G Digital CDMA
 U.S. / Qualcomm
2.5G Standards – TDMA/CDMA
 CDMA2000 – 3G U.S./Qualcomm
 W-CDMA – 3G Europe

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2.5G CDMA Standard
Only one upgrade path for IS-95 CDMA (CDMAOne)
 2.5G interim CMDA standard is IS-95B

 High-speed packet and circuit switched data access
 Original IS-95 data rate was 9.6 kbps
» Data rate actually deployed by Sprint PCS and Verizon was 14.4
kbps (IS-95A)
 Multiple orthogonal PN spreading codes per user
» Each user to take up to 8 different PN spreading codes in parallel
» Maximum instantaneous data rate = 8 x 14.4 = 115.2 kbps
» Practical data rate was only about 40-64 kbps
 Sprint PCS “Wireless Web”
» Began use in 2000 using IS-95B
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2.5G CDMA Standard

IS-95/IS-95A Soft Handoff
 Mobile unit reports RSS back to MSC through current


serving BS several hundred times per second
MSC decides when to initiate soft handoff (multiple
serving BSs on same radio channel)
IS-95B Hard Handoff
 Mobile unit searches for different 1.25 MHz radio



channels without approval from MSC
Rapidly tune to new channel if better than serving channel
Hard handoff available in addition to soft handoff
Improves link quality in congested cells where multiple
radio channels are being used
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2.5G CDMA Standard

IS-95B Upgrade
 No new hardware required (baseband or RF)
 Only software upgrade at BS
 New mobile unit handsets
» Backwards compatible with IS-95A
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2.5G Standards

2.5G Summary
 All designed to overlay on existing 2G networks
 No new frequency spectrum required
 Practical data rates:
»
»
»
»
IS-95B  40-64 kbps (packet or circuit switched)
HSCD  57.6 kbps (circuit switched single user)
GPRS  50 kbps (packet switched multi-user)
EDGE  100-120 kbps (packet switched multi-user)
 EDGE requires significant new RF hardware and software
upgrades
» Modulation technique upgraded to 8-PSK
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2.5G Standards
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3G Wireless

3G Vision
 Fully data-centric communication networks
 Multi-megabit per second data rates
 Voice over Internet Protocol (VoIP)  packet-based voice
 Always on access

Applications
 Live video and music
 Interactive multi-person web sessions
 Multi-party conferencing with simultaneous voice and data
access
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3G Wireless
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3G Wireless
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3G Wireless

3G History
 International Telecommunication Union (ITU)
» Formulate truly global 3G standard for 2 GHz band
 International Mobile Telephone 2000 (IMT-2000) Plan
» Active forum for proposal, development, and debate of global 3G
communication standard (started in 1996)
 Worldwide user community split into two camps based on
2G outcome: CDMA (IS-95) and GSM (GPRS/EDGE)
» Many standards initially proposed and debated but this was
narrowed to two leading candidates (most manufacturing support)
» 3G GSM  Wideband CDMA (W-CDMA)  3G Partnership
Project (3GPP)
» 3G CDMA  CDMA2000  3G Partnership Project 2 (3GPP2)
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3G Evolution
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3G Wireless

3G Deployment
 Countries everywhere allocated new/more spectrum

specifically for 3G
Some early 3G spectrum auctions
» $35B (USD) in England in 2000  5 nationwide licenses
» $46B (USD) in Germany in 2000  4 nationwide licenses
 Commercial grade 3G equipment was first deployed in


U.S. in 2005
First 3G deployment was 2002 in Japan
Sprint PCS rolled out first US 3G network
» CDMA 2000 1xRTT
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W-CDMA

3G W-CDMA (UMTS)
 Also know as Universal Mobile Telecommunication



System (UMTS)
UMTS first started development in 1996 by consortium of
European service providers, manufacturers, and
governments (ETSI)
Other competing wideband CDMA standards merged with
UMTS in 2000
Ensures backwards compatibility with GSM, GPRS,
EDGE network structure and bit-level packaging
» Completely new CDMA air interface
» NOT backwards compatible with baseband and RF hardware in BS
» Completely new base stations required
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W-CDMA

3G W-CDMA
 Minimum of 5 MHz BW required for one RF channel
» 4 times larger than 1.25 MHz RF BW for IS-95
 Multiple RF channels would be required to support large number of
high speed users
» Requires significant new spectrum
 Complete change out of base station RF & baseband hardware
 Supports data rates from 8 kbps to 2 Mbps (stationary users only)
» Determined by available network capacity and user requirements
 100-350 simultaneous voice calls
» Depends on channel conditions, user velocity, etc
 Future W-CDMA versions (4G) support up to 8 Mbps
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W-CDMA

3G W-CDMA
 6 times increase in capacity relative to GSM on a system
wide basis
Example: 200 simultaneous voice calls in 5 MHz  25 kHz/user,
GSM 8 users per 200 kHz channel  25 kHz/user, but 100%
frequency reuse in W-CDMA vs. N = 4 for GSM
 Always on packet based wireless
» Computers, PDAs, phones, etc. share network and continuously
connected to internet
 FDD and TDD modes
» Mobile cellular  FDD (separate F/R channels)
» Indoor portable/cordless  TDD (1 channel shared in time for F/R)
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W-CDMA

3G W-CDMA
 Support advanced high data rate services
»
»
»
»
Streaming audio/video
Videoconferencing
Video games
Broadcast TV!
 Public and private network features
 Slow and gradual deployment due to new BS hardware
and new spectrum
» Dual mode or tri-mode phones to support GSM, EDGE, and WCDMA
 W-CDMA was fully installed by 2010
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CDMA2000

3G CDMA 2000
 Seamless evolutionary path for 2G IS-95 and 2.5G IS-95B
» Must retain original 1.25 MHz IS-95 RF BW structure!!
 Left over from AMPS carriers not willing to risk more than 10%
of their allocated 12.5 MHz spectrum!!
 Gradual deployment with existing IS-95 2G and 2.5G
systems
»
»
»
»
Deploy on cell by cell basis
No wholesale hardware changeout
No new spectrum required
Significant advantages/distinctions relative to W-CDMA
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CDMA2000

3G CDMA2000
 US Telecommunication Industry Association (TIA)
oversaw the standard development
» Compared to ETSI (European Telecommunication Standards
Institute) for W-CDMA
» Qualcomm is major developer of CDMA2000
 International collaborators as well
 First version of CDMA2000 was 1xRTT (1X)
» Multi-carrier (multiple RF channels) but first deployment allowed
only 1 channel!!
» 307 kbps maximum data rate and 144 kbps typical throughput
 IS-95B has only 40-50 kbps typical throughput
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CDMA2000

3G CDMA2000
 1xRTT (1X)
» Multi-level keying (PSK) and multiple PN spreading sequences
 Both are rapidly adaptable based on network capacity, user
need, and channel conditions
 Incremental redundancy like EDGE!
» All changes are baseband signaling changes
» No new RF hardware required
» All changes done in baseband hardware/software
 Cell by cell basis if desired!!
» Packet network hardware must also be installed @ MSC
» Supports 2 x voice users as IS-95 and double the battery life
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CDMA2000

3G CDMA2000
 3xRTT (3X)
» Multi-carrier CDMA
» 3 RF carriers  3 x 1.25 MHz = 3.75 MHz cumulative BW
» 3 adjacent RF carriers (option 1)
 Creates single 3.75 MHz channel & requires new RF hardware
» 3 non-adjacent RF carriers (option 2)
 No new RF hardware
» Packet data throughput up to 2 Mbps (just like W-CDMA)
 Actual rate depends on network capacity, mobile velocity,
channel conditions, etc.
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3G Wireless

CDMA2000 vs. W-CDMA
 US vs. Europe
 CDMA2000 had advantages of more seamless, gradual,
and economically viable deployment
» More rapid rollout of 3G than W-CDMA
» Sprint PCS had nationwide 3xRTT in US
 W-CDMA had advantage of 4 to 1 GSM-based installed
user population
» Greater manufacturing support
» Less rapid rollout due to RF hardware upgrades
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