PCS
What is PCS?
Related Wireless Technologies
PCS Spectrum in U.S.
1.9 GHz and lmplications
Two Paradigms of PCS Infrastructure
Mobility Switching Paradigms
Implication of Roaming
PCS Air-interface Proposals
DCS1900 Characteristics
DCS 1900 Frame Structure
GSM Network Architecture
CDMA Characteristics
Soft-Handoff and Softer-Handoff
Power Control and Capacity
Upbanded IS-136 Characteristics
High-Tier PCS Directions
PACS Characteristics
PACS Architecture and Frame Format
DECT/PHP/CH2 Characteristics
Low-Tier PCS Directions
PCS Market Prospects
PCS Market Prospects
Major PCS Players
| What is PCS? |
|---|
♦ Personaf number, anywhere in the country, dial in and dial out
♦ Personal Mobility + Terminal Mobility
♦ 1800 MHz or 1900 MHz band services
Light-weight, low-power, personal handset
Lower cost than Cellular
Voice Quality close to wireline quality
Additional Services
wireless data, fax, and image transmission,
additional features
ISDN-Iike user features
Seamless access between cordless phone service at home, wireless PABX in office, and cellular-like service on the street
| Related Wireless Technologies |
|---|
♦ Pager + Pay Phone (poor man's PCS)
♦ GPS
♦ CT-2/DECT
♦ Cellular (macrocell and microcell)
♦ Enhanced Special Mobile Radio (ESMR) - Dispatch + Cellular
♦ Satellite Mobile (LEO/MEO/GEO etc.)
♦ Wireless LAN
♦ Wireless PABX
Sun Feb 6 00:47:57 CST 2011| PCS Spectrum in U.S. |
|---|
| 1.9 GHz and lmplications |
|---|
♦ Generally require 10 dB more power than 800 MHz to propagate the same distance
FCC increased ERP limit to 1000 W per carrier
Power for hand-held unit, however, is still limited to 0p.6 Watt average, causing significant link imbalance
R.F. components at 1.9 GHz typically of lower power, higher noise figure, or greater insertion loss than their 800 MHz counter parts
Components geometry is about 45% of their 800MHz equivafent
Tower-mounted electronics and ''smart'' antennas important technology to extend range
tower mounted LNA improve system noise figure
"smart" antenna provides extra gain where you need it
n-branch diversity (n>2) improves overall performance
| Two Paradigms of PCS Infrastructure |
|---|
♦ Cellular-like NSS
Mobile Switch
HLR/VLR
IS-41 or similar protocOI
♦ Medium-to-Large Cells
high tower
Cellular-like Air interface
"smart" antennas
♦ Cellular-like Subscriber Subscriber Units
SU cost no cheaper than cost than cellular
♦ PSTN-Iike NSS
Central Office Switch
Adjunt Processor
♦ Small Cells
pole-mounted
high capacity
not designed to handle high mobility
♦ Digital cordless phone-like
potentially much lower cost than cellular
inherently low power consumption
| Mobility Switching Paradigms |
|---|
| Implication of Roaming |
|---|
U.S, Digital Cellular uses AMPS as common basis for roaming
Given the number of different air interfaces exist, AMPS may again be the only common basis for roaming
Requiring dual-band, duaf-mode subscriber units, increase subscriber unit cost
IS-41 will continue to govern intersystem handoff
Establish pairwise roaming agreement with neighbors
No problem if neighbor shares the same air interface
Need to set aside a small band for roaming purpose
| PCS Air-interface Proposals |
|---|
⊕ DCS 1900 (Upbanded GSM)
Modified from DCS1800 in Europe
Considered readily available, thus gain early acceptance
BellSouth, American Personal Communications, PacBell, Western Wireless, Cox Cable
⊕ CDMA (Narrowband CDMA)
Upbanded IS-95
IS-95 system has yet seen operation in the cellular band
PCS Prime Co.(Airtouch, US West, Nynex, BellAtlantic),
Wireless Co. (Sprint, TCI)
⊕ Upbanded IS-54/136
Modified from IS-136, Which is IS-54, the U.S. Digital
Cellular (TDMA) Standard, with Digital Control Channel
- AT&T Wireless, Rogers Cantel
⊕
Omnipoint
The only TDD system proposed
Pioneer Preference (NY MTA)
⊕ PACS(low-tier and unlicenced)
Low-tier System based on Bellcore's design
Some Personal Handy Phone (PHP) characteristics are incorporated
Not designed to cover rural and highway
May see applications in highly populated BTAs
⊕ PHP(low-tier)
Time-Division Duplex (TDD)
⊕ Unlicenced Band
Systems/Devices operates in the unlicenced band requires no formal standards process, but will have to meet the UTAM approval
| DCS1900 Characteristics |
|---|
Upbanded GSM, designed for Cellular like service
Operate at reasonably low C/l (9 dB), allowing a 3x4 reuse pattern
200 kHz channeiization
UP to 6 carriers per sector in a 15-MHz band
. 8-slot TDMA format with a short TDMA frame
At least one digital control channel per carrier
13.3 kbps full-rate vocoder
Well-defined NSS/BSS interfaces allows service providers to mix and match differnet vendor equipment
An enhanced vocoder are being considered, a half-rate vocoder also under development
Multi-symbol equalizer equalizes up to 15 psec delay spread
| DCS 1900 Frame Structure |
|---|
| GSM Network Architecture |
|---|
| CDMA Characteristics |
|---|
Upbanded IS-95, designed for cellular-like service
Operate at low C/I (7 dB), capacity claim dependent on the operating point
Reuse factor iS ONE, achieved by sOft hand-off, capacity claim dependent on it
1.25 MHz channelization, but require additional guard band at the band edge. At most three carriers in a BTA allocation
A guard zone of about 145dB is also required
Variable rate vocoder
8 kpbs is used if capacity is considered important
a higher-quality 13 kpbs "True Voice" vocoder is being considered
Power control capability essential for capacity and voice quality
| Soft-Handoff and Softer-Handoff |
|---|
| Power Control and Capacity |
|---|
Power control is ABSOLUTELY ESSENTIAL to achieve capacity
Fade rate is more than double in 1.9 GhZ over the 800 MHz band
Typical capacity quoted by manufactures are 20-22 calls per sector for 8 kbps and 13-15 calls per sector for 13 kbps
| Upbanded IS-136 Characteristics |
|---|
Upgraded from IS-54 by adding a digital control channel (DCCH)
Enhanced new Features
two-way alphanumeric paging
differentiated access
sleep mode
Requiring relatively high C/l, corresponding to 3x7 reuse pattern
30 kHz channelization, 26 carriers/sector in a 15 MHz band
p /4-QPSK Modulation, 48.6 kbps per channel, 25 frame/second
3-slot TDMA with a 20 msec frame (2 slots in 40 msec trame)
ITU G.729 8 kbps may be adopted
One-symbol equalizer equalizes up to 40 m sec delay spread
| High-Tier PCS Directions |
|---|
need to balance the forward and reverse link
Wide-band Basestation Architectures
supporting multiple air-interface on the same hardware platform
Open Network Architecture (Switch/Radio Subsystem interface)
Power Efficient wide-band Linear Power AmplifierS
needed to support wide-band basestations and smart antennas
reduce size of R.F. portion of the basestation
High-efficiency power modules for hand-held units at 1.9 GHz
Power efficient R.F. and mixed signal ASICs
Power efficient DSP and digital ASICs
| PACS Characteristics |
|---|
Pole-mounted low-tier cells
Operated at high C/l (17dB), rectangular cell plan with 16-cell reuse
300 kHz channelization, 16 channels per BTA, 50 channels per MTA
Typically one carrier per radio port, some may have two carriers
8-slot TDMA with a short frame duration, one control slot
32 kbps ADPCM high-quality voice, and high-speed data capability
Low delay air-interface, requiring no echo-canceller on the switch
No FEC coding, no equalizer, use CRC and error concealment
Recommended cell spacing is 700 m
Use central office switch
Low-mobility
| PACS Architecture and Frame Format |
|---|
| DECT/PHP/CH3 Characteristics |
|---|
| Low-Tier PCS Directions |
|---|
⊕ New Technologies
♦ Dynamic Channel Allocation
♦ High mobility features
♦ CATV Interface capability
⊕ New Applications
♦ Home basestation/cordless phone
♦ Wireless PABX
♦ Wireless Centrex
♦ Wireless ISDN
⊕ Added Features
♦ Personal Digital Assistant (PDA)
♦ Wireless Video/Graphics
Sun Feb 6 00:48:01 CST 2011| PCS Market Prospects |
|---|
| PCS Market Prospects |
|---|
| Major PCS Players |
|---|