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

Type	Lower (MHz)	Upper (MHz)
Narrowband	900	901
Narrowband	930	931
Narrowband	940	941
Broadband	1850	1910
Unlicensed	1910	1930
Broadband	1930	1990

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:

• Deutshe Telecom bought VoiceStream (formerly Western Wireless).
• SBC Communications and BellSouth formed Cingular Wireless.
  • When SBC acquired Ameritech in 1999, 20 Ameritech Cellular properties were sold (most went to GTE).
• Bell Atlantic, Nynex, GTE and AirTouch merged to form Verizon Wireless.
  • Vodafone is a partner as well.
  • Seven of ten PrimeCo markets became Verizon Wireless.
    • Former PrimeCo Chicago was (eventually) sold to U.S. Cellular.
    • Former PrimeCo Houston was sold to AT&T.
    • Former PrimeCo Richmond was sold to nTelos.

• NTT DoCoMo (owned by Nippon Telegraph and Telephone) has taken a financial stake in AT&T Wireless.

• Sprint and Nextel announce their merger on December 15, 2004. Together, at the time of the announcement the two companies have a combined customer base of about 35 million subscribers.
  (Sprint will go on to massive subscriber losses, including more than 4 million in 2008.)
  (The Nextel iDEN network will have about 15 million subscribers as of mid-2009.)

• Cingular bought AT&T Wireless.

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

Here's how things looked in 1997.

Type	Provider
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:

AMPS	Advanced Mobile Phone System
N-AMPS	Narrowband AMPS
D-AMPS	Digital AMPS
GSM	Global System for Mobiles
CDMA	Code 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.