Method and apparatus for providing a communication path using common sites

In a radio communication system having a plurality of sites, wherein each site has a corresponding coverage area, and wherein at least some of the coverage areas overlap with one another, a method of providing a communication path among a group of communication units, comprising the steps of:

• A) establishing an inclusion list which identifies sites to be included in establishing the communication path;
• B) determining whether members of the group of communication units can be serviced by only one site of the plurality of sites, and identifying said only one site;
• C) when at least one group member can be serviced by only one site, adding said one site to said inclusion list;
• D) determining whether remaining group members are currently being serviced by different sites;
• E) when said remaining group members are currently being serviced by different sites, identifying a set of common sites which can provide service to said remaining group members;
• F) adding said set of common sites to said inclusion list;
• and
• G) establishing the communication path using said identified sites in said inclusion list.

A site controller for use in a radio communication system having a plurality of sites, wherein each site has a corresponding coverage area, and wherein at least some of the coverage areas overlap with one another, the radio communication system having at least a first and second communication unit, where the first communication unit requests a communication with the second communication unit, the site controller comprising:

• A) means for determining whether the first and second communication units are currently being serviced by different sites;
• B) means for determining whether the first and second communication units which are currently being serviced by different sites can be serviced by a common site;
• and
• C) means for establishing a communication path through said common site when the first and second communication units are serviceable by a common site.

A site controller for use in a radio communication system having a plurality of sites, wherein each site has a corresponding coverage area, and wherein at least some of the coverage areas overlap with one another, the site controller comprising:

• A) storage means for storing an inclusion list which identifies sites to be included in establishing a communication path among a group of communication units;
• B) means for determining whether members of the group of communication units can be serviced by only one site, and including means for identifying such sites as required sites;
• C) means for altering said inclusion list to include said required sites;
• D) means for determining whether remaining group members are currently being serviced by different sites;
• E) means for identifying, among said different sites servicing those of said remaining group members, a set of common sites which can provide service to said remaining group members;
• F) means for altering said inclusion list to include said set of common sites;
• and
• G) means for establishing said communication path using said sites identified in said inclusion list.

In a radio communication system having a plurality of sites, wherein each site has a corresponding coverage area, and wherein at least some of the coverage areas overlap with one another, a method of providing a communication path between a first and a second communication unit, comprising the steps of:

• A) determining whether the first and second communication units are currently being serviced by different sites;
• B) when the first and second communication units are currently being serviced by different sites, determining whether the first and second communication units can both be serviced by a common site by:
• B1) at the first communication unit, monitoring signals from at least a primary site that currently provides service to the first communication unit;
• B2) measuring at least one quality metric for at least some of the monitored signals;
• B3) using the at least one measured quality metric to determine whether the first and second communication units can both be serviced by the common site;
• and
• C) when the first and second communication units are serviceable by the common site, establishing the communication path between the first and second communication units using the common site.