Signal strength controlled directed retry in a mobile radiotelephone system

An apparatus for controlling communications with a mobile station in a radiotelephone network, comprising:

• means for receiving a service request from said mobile station at a base station;
• means for measuring at said base station the signal strength of a signal from said mobile station during said service request;
• means for ascertaining whether said service request can be accepted based on the availability of voice channels assigned to said base station;
• means, responsive to a determination by said means for ascertaining that said service request cannot be accepted, for comparing said signal strength with at least one threshold value;
• and
• means, responsive to said comparing means, for directing said mobile station to retry said service request on one or more of a first set of channels if said signal strength exceeds said threshold value, and otherwise, for directing said mobile station to retry said service request on one more of at least a second set of channels.

In a cellular mobile radiotelephone system having a plurality of cells and a plurality of mobile stations, a method of reducing interference in said system of a call made by a mobile station when setting up said call within a congested cell, comprising the steps of:

• obtaining an indication of said mobile station's location relative to a probability of interference with established calls by setting up said call in said congested cell;
• freely allowing said mobile station to retry setting up said call in at least one neighboring cell when said mobile station is indicated as being located in an area of said congested cell where interference with established calls by the setting up of said call is likely to be small;
• and
• restricting said mobile station from retrying setting up said call when said mobile station is indicated as being located in an area of said congested cell in which interference with established calls by the setting up of said call is likely to be greater.

In a cellular mobile radiotelephone system having a plurality of cells and a plurality of mobile stations, an apparatus for reducing interference in said system of a call made by a mobile station when setting up said call within a congested cell, comprising:

• means for locating said mobile station relative to a probability of interference with established calls by setting up said call in said congested cell;
• means for allowing said mobile station to retry setting up said call in at least one neighboring cell when said mobile station is located in an area of said congested cell where interference with established calls by the setting up of said call is likely to be small;
• and
• means for restricting said mobile station from retrying setting up said call when said mobile station is located in an area of said congested cell where interference with established calls by the setting up of said call is likely to be greater.