JPL's Wireless Communication Reference Website Chapter: Cellular Telephone Networks

Typical frequency reuse plan for 7 different radio frequencies, based on hexagonal cells. Radio channels are indicated by color. In fact some problems in cellular frequency assignment are solved using map coloring theory.

Particularly in the United States, the term "cell phone" is often used by the public when a wireless phone is meant. The cellular approach was proposed and developed predominantly by the Bell System, in the U.S. in the early 70's, after the regulatory agency FCC has asked for an upgrade of the existing radio telephone service. The FCC had the foresight to require:

• a large subscriber capacity
• efficient use of spectrum resources
• nationwide coverage
• adaptability to traffic density
• telephone service to both vehicle and portable user terminals
• telephony but also other services including closed user groups with voice dispatch operations
• toll quality
• affordability, which could eventually make it a mass-market service

Start page of video from Short Course by BMRC

Video from Wireless Communications Networks Short Course "In wireless communication, we attempt to accommodate as many users as possible, and the way we do this is by very dense frequency reuse. We split the area that we want to cover into many small "cells" and in each of these cells we use a different frequency. If we use a frequency in one geographical area, we want to reuse it in another area. Relative to the size of the cell, we want to make the distance between the cells that use the same frequency as small as possible. The price that we pay is that we get interference from one cell to other cells. So we have to build a system in which the receivers are relatively immune to interfering signals. .....

Embedded QuickTime Video

Examples of systems using cellular frequency reuse are GSM and AMPS.

Coverage of cellular telephone systems by the year 2000.

There was an estimated 13,000,000 users of cellular phones in the U.S. alone in 1995, and marketeers expected that the cellular market growed by more than 25% per year for the next five years. Worldwide sales of mobile phones was around 500 Million in 2003 and is expected to reach 1 Billion around 2012.

More on Cellular Telephone Networks

• Frequency reuse, cell sizes
• Multiple access: FDMA, TDMA, CDMA
• Network aspects,
  • Handover, soft handover
  • Security
• Cell sectorization, reuse partitioning, dynamic channel allocation
• Practical aspects of cell planning
• Cumulation of interference, Nakagami fading, model by Schwartz & Yeh
• Spectrum efficiency versus performance
• Outage probability, Computer methods.
• Call blocking, speech clipping, subjective speech quality, Erlang B and C formulas
• Digital Speech Interpolation (DSI)
• Man-made noise and link-budget
• Radio Technologies and Standards:
  • First and Second Generation (PDF slides): GSM, ...
  • Future standards (PDF slides): IMT 2000, ...
  • US standards: AMPS, IS54, IS95, PCS 1900, PCS (PDF slides)
• Business aspects: costs, tariffs, ...
  • GSM business aspects

JPL's Wireless Communication Reference Website © 1993, 1995.