Personal Communication Services

CONTENTS

What is PCS?
Frequency Allocations
Radio Link Standards
Access Methods
Security Issues
FCC Auctions
Further Information

WHAT IS PCS?

Personal Communication Services (PCS) is the name given to a number of wireless technologies and services that typically operate in the 2 GHz range. The FCC has allocated 140 MHz of space between 1850 MHz and 1990 MHz for broadband PCS and 3 MHz in the 900 MHz range for narrowband PCS.

This space has been licensed by the FCC to the highest bidder in an auction process that began in 1994 and completed in January 1997.

Auction winners are now in a build-out process to complete their networks and start earning back some of the billions they paid into the U.S. Treasury for these frequencies.

Big players are Sprint PCS, AT&T, and PrimeCo, as well as others listed below.

PCS FREQUENCY ALLOCATIONS

TypeLower (MHz)Upper (MHz)
Narrowband900901
Narrowband930931
Narrowband940941
Broadband18501910
Unlicensed19101930
Broadband19301990

Wireless handsets transmit between 1850 MHz and 1910 MHz.
Base stations transmit between 1930 MHz and 1990 MHz.

STANDARDS

There's been a lot of consolidation in the wireless industry over the past few years. Here are some highlights:

Type Provider U.S. Cellphones
Year-end 2002
U.S. Cellphones
Projected 2007
Code Division Multiple Access
(CDMA)
Sprint PCS
U.S. Cellular
Verizon Wireless
43% 44%
Global System for Mobiles
(GSM-1900)
AT&T Wireless
Cingular Wireless
VoiceStream
11% 33%

(This list is not complete. Send any updates to me.)

Here's how things looked in 1997.
TypeProvider
Code Division Multiple Access
(CDMA)
AirTouch
ALLTEL Communications
Ameritech Cellular Services
BC TEL Mobility (Canada)
Bell Atlantic Mobile
Bell Mobility Cellular (Canada)
Clearnet (Canada)
GTE Wireless
NextWave Telecom
PrimeCo Personal Communications
Sprint PCS
US West
Global System for Mobiles
(GSM-1900)
Aerial Communications
Airadigm Communications
BellSouth Mobility DCS
Conestoga Wireless Company
Cook Inlet PCS
DIGIPH PCS
Microcell Telecommunications [Fido] (Canada)
NPI Wireless
Omnipoint Communications
Pacific Bell Mobile Services
Powertel
Western Wireless
Wireless 2000 PCS
Digital Advanced Mobile Phone Service
(D-AMPS)
AT&T Wireless
Southwestern Bell
Cantel (Canada)

ACCESS METHODS

AMPS N-AMPS D-AMPS GSM CDMA
Standard IS-91 IS-88 IS-136 GSM IS-95
Channel Size 30 kHz 10 kHz 30 kHz 200 kHz 1.25 MHz
Total Channels 832 2412 832 1000 (MTA) -
Users Per Channel 1 1 3 8 -
Voice Channels Analog
FDMA
Analog
FDMA
Both
TDMA
Digital
TDMA
Digital
CDMA
Control Channels FDMA FDMA FDMA TDMA CDMA
Channel Reuse Factor 7 7 7 or 4 4 or 3 1
Channels per Cell Site 119 357 357 or 625 250 or 333 1
Capacity vs. AMPS 1 3 3 2.3 or 3.4 6 - 20

Notes:
AMPSAdvanced Mobile Phone System
N-AMPSNarrowband AMPS
D-AMPSDigital AMPS
GSMGlobal System for Mobiles
CDMACode Division Multiple Access

SECURITY

Yeah, right.

Click here for information on how part of the IS-136 and IS-95 encryption scheme was broken.

Click here for information on how the GSM COMP-128 (A3/A8) authentication algorithm was cracked.

Click here for detailed information about the GSM authentication process.

Click here for an implementation of the GSM A5/1 "voice privacy" algorithm.


FCC AUCTIONS

SERVICE Number of
Licenses
Revenue
in Millions
Nationwide Narrowband PCS 10650
Interactive Video and Data Services 594249
Regional Narrowband PCS 30395
Broadband PCS (A and B Blocks) 997,736
Broadband PCS (C Block) and reauction 49310,174
Multipoint Distribution Service 493216
900 MHz Specialized Mobile Radio 1020213
Digital Broadcasting Service (110°) 1683
Digital Broadcasting Service (148°) 152
Cellular Unserved 142
TOTAL 422722,887


FURTHER INFORMATION

Cingular
PrimeCo Personal Communications
Qualcomm, Inc.
Sprint PCS
U.S. Cellular


Send mail to Dan Veeneman
Updated November 12, 2005
Brief updated in July 2009.