Load balancing for cellular radiotelephone system

In a cellular mobile radio telephone communications system of the type including plural geographically-separated radio base stations serving corresponding plural discrete geographical cells, adjacent ones of said cells overlapping one another, each of said base stations including radio transceiver means for communicating over a prespecified plurality of voice communications channels allocated to the cell served thereby simultaneously and independently with a corresponding plurality of mobile radio transceivers located within the cell, an improvement comprising:

• determining, for at least one cell, a voice channel occupancy level indicating the number of voice communications channels allocated thereto being used for communications with respect to the total number of voice channels allocated thereto;
• comparing said determined voice channel occupancy level of said cell with a predetermined threshold level;
• and
• if said comparison reveals the voice channel occupancy level of said cell exceeds said threshold level, transferring communications from the base station serving the cell to the base station serving an adjacent cell.

A central controller adapted for communicating control signals to/from plural stationary geographically-separated radio transceivers, said plural stationary transceivers of the type serving respective corresponding overlapping geographical areas and communicating radio signals to/from mobile radio transceivers located in said areas over radio communications channels preallocated thereto, said central controller including a digital signal processor connected to communicate said control signals and programmed so as to perform the following functions:

• monitor the number of radio communications channels being used for communications by each of said plural stationary transceivers;
• determine, for each stationary transceiver, a measure of the number of communications channels being used for communications with respect to the number of communications channels preallocated thereto;
• and
• control stationary transceivers having high determined measures to shift communications to stationary transceivers having low determined measures and serving geographically-neighboring areas.

In a cellular radiotelephone communications system of the type including first and second geographically-separated stationary radio transceivers, said first stationary transceiver for communicating radio signals over a first plurality of communications channels preallocated thereto with physically-distinct mobile radio transceivers located in a first geographical area, said second stationary transceiver for communicating radio signals over a second plurality of communications channels preallocated thereto with physically-distinct mobile radio transceivers located in a second geographical area, said first and second geographical areas overlapping one another, an improvement comprising a method of balancing the relative loading of said first and second stationary transceivers comprising the steps of:

• (1) determining the number of said first plurality of channels being used for communicating signals between said first stationary transceiver and said mobile radio transceivers;
• (2) determining the number of said second plurality of channels being used for communicating signals between said second stationary transceiver and said mobile radio transceivers;
• and
• (3) if said first-mentioned number exceeds a first predetermined threshold associated with said first stationary transceiver and said second-mentioned number is less than a second predetermined threshold associated with said second stationary transceiver, directing a selected mobile transceiver located in both said first and second geographical areas and tuned to one of said first plurality of channels to retune to one of said second plurality of channels and begin communicating radio signals with said second stationary transceiver.

In a cellular radiotelephone communications system of the type including first and second geographically-separated stationary radio transceivers, said first stationary transceiver for communicating radio signals over a first plurality of radio communications channels preallocated thereto with physically-distinct mobile radio transceivers located in a first geographical area, said second stationary transceiver for communicating radio signals over a second plurality of communications channels preallocated thereto with physically-distinct mobile radio transceivers located in a second geographical area, said first and second geographical areas overlapping one another, a controller means connected to transmit control signals to and receive control signals from said first and second stationary radio transceivers, said controller means for:

• (1) determining the number of said first plurality of channels being used for communicating signals between said first stationary transceiver and mobile radio transceivers,
• (2) determining the number of said second plurality of channels being used for communicating signals between said second stationary transceiver and mobile radio transceivers, and
• (3) directing a selected mobile transceiver located in both said first and second geographical areas and tuned to one of said first plurality of channels to retune to one of said second plurality of channels and begin communicating radio signals with said second stationary transceiver if said first-mentioned number exceeds a first predetermined threshold associated with said first stationary transceiver and said second-mentioned number is less than a second predetermined threshold associated with said second stationary transceiver.

In a cellular radiotelephone communications system of the type including first and second geographically-separated stationary radio transceivers, said first stationary transceiver for transmitting radio signals over a first plurality of radio communications channels preallocated thereto to a first geographical area and for receiving radio signals transmitted over said first plurality of channels, said second stationary transceiver for transmitting radio signals over a second plurality of radio communications channels preallocated thereto and for receiving radio signals transmitted over said second plurality of channels, a mobile radio transceiver located in both said first and second geographical areas and including:

• tunable transceiving means for transmitting and receiving radio signals over a radio communications channel;
• tuning means connected to said transceiving means for tuning said transceiving means to one of said first plurality of channels;
• and
• control means connected to said tuning means for controlling said tuning means to retune said transceiving means to one of said second plurality of channels if a measure of the number of said first plurality of communications channels being used by said first stationary transceiver for transmitting/receiving radio signals exceeds a predetermined threshold and the number of said second plurality of communications channels being used by said second stationary transceiver for transmitting/receiving radio signals is less than said predetermined threshold.