Communication network prioritization system for mobile unit

A trunked communication system utilizes information on mobile unit location provided by a mobile unit to provide prioritized communication system availability. By further utilizing location information, the trunked communication system also provides a current communication system as a highest priority communication system as a mobile unit moves into a non-receiving area within an area served by the current communication system.

TECHNICAL FIELD 
This invention relates generally to mobile radio systems with location 
sensors that assist a user when changing geographical positions. This 
invention relates more particularly to a method of providing prioritized 
communication system availability information to a mobile unit user. 
BACKGROUND OF THE INVENTION 
Information systems supporting mobile units in computing location are 
known. The mobile unit user determines its location utilizing a location 
determining mechanism containing data bases of geographical information, 
for example, roads, rivers, landmarks, and so forth. Then the mobile unit 
user sends this information to a control base. The present systems provide 
the mobile unit with a comprehensive listing of communication systems 
available. 
As a mobile unit user moves from a geographical area supported by one 
communication system to another geographical area supported by another 
communication system, it becomes desirable to provide the mobile unit user 
with the capability of determining the identity of the most readily 
available communication system without undue time expenditure. 
Accordingly, there exists a need for a mobile unit user interface that 
minimizes the time required to select a valid adjacent communication 
system when the mobile unit user moves from a geographical area supported 
by one communication system to a geographical area supported by another 
communication system. 
SUMMARY OF THE INVENTION 
This need and others are substantially met by the communication network 
prioritization system based on location information as set forth in the 
present invention. This system includes generally an input mechanism for 
accepting location information regarding the within a particular location, 
an output mechanism for selectively providing user with a prioritized list 
of closest valid adjacent communication systems available to user, and an 
output mechanism for providing a highest priority communication system 
available to a user about to enter a non-receiving area.

BEST MODE FOR CARRYING OUT THE INVENTION 
A plurality of trunked communication systems (depicted as A, B, and C, but 
not limited to that number) providing prioritized communication system 
availability information to mobile units (depicted as 108, later 108', but 
where a substantially larger number may be present) in accordance with the 
invention are set forth in FIG. 1, as depicted generally by the numeral 
100. 
In one embodiment, in a networked trunked system (100), a hub controller 
(110) and a plurality of resource controllers (shown as 102A, 102B, 102C, 
but not limited to that number) direct a plurality of systems (shown as A, 
B, and C, but not limited to that number) that incorporate the use of 
local computers to coordinate, assign and catalog the provision of 
prioritized communication system availability information to a plurality 
of mobile unit users (depicted as 108, later 108', but where a 
substantially larger number of users may be present). The hub controller 
(110) serves as a central data storage and retrieval unit. 
As a mobile unit (108) moves about, the unit utilizes a location 
determining system known in the art, for example, Loran C, to establish at 
least an approximate location determination within a particular location. 
The mobile unit (108) transmits the approximate location determination to 
a local resource controller (102A). The resource controller (102A) 
utilizes a local computer (104A) that determines whether the mobile unit 
(108) is about to enter a non-receiving area or a peripheral receiving 
area and transmits a prioritized inventory of at least one valid adjacent 
communication system available adjacent to the particular location of the 
mobile unit (108), the mobile unit having a memory means for storing an 
inventory of at least a first available communication system, as a 
function, at least in part, of the location of the mobile unit. 
FIG. 2 illustrates the steps executed by a resource controller (102A), as 
generally depicted by the numeral 200. When the resource controller (102A) 
receives approximate mobile unit location information (202) from a mobile 
unit (108), it utilizes a local computer (104A) that determines whether 
the mobile unit (108) is entering a peripheral receiving area (204). If 
the resource controller determines that the mobile unit (108) is entering 
a peripheral receiving area, the resource controller (102A) utilizes a 
local computer (104A) to develop a prioritized list of closest valid 
available communication systems (206), adjacent to the particular location 
containing at least one such system, for the mobile unit in conformity 
with the approximate mobile unit location information. The resource 
controller (102A) transmits the prioritized list of closest valid 
available communication systems (206) to the mobile unit (108') and 
returns to the determination of receiving approximate mobile unit location 
information (202). If the resource controller (102A) utilizes, at least in 
part, the location of the mobile unit, to determine that the mobile unit 
is not entering a peripheral receiving area, the resource controller 
(102A) utilizes, at least in part, the location of the mobile unit to 
determine whether the mobile unit is entering a non-receiving area (208) 
adjacent to the particular location. If so, the resource controller (102A) 
utilizes a local computer (104A) to provide the mobile unit (108) with the 
current communication system as a highest priority system available (210). 
If the resource controller (102A) utilizes, at least in part, the location 
of the mobile unit, to determine that the mobile unit (108) is not 
entering a non-receiving area, the resource controller (102A) returns to 
the determination of receiving approximate mobile unit location 
information (202). 
FIG. 3 illustrates the steps executed by a mobile unit (108), as generally 
depicted by the numeral 300. The mobile unit (108) determines an 
approximate location information (302), utilizing at least one location 
determining device. The mobile unit (108) transmits the approximate 
location information (304) to a local resource controller (102A). If the 
mobile unit (108) receives a current communication system (A) as a highest 
priority communication system available (306), the mobile unit (108) 
returns to the determination of approximate location information (302). If 
the mobile unit (108) does not receive the current communication system 
(A) as a highest priority communication system available, the mobile unit 
(108, now 108'), receives a prioritized list of closest valid available 
communication systems (308) containing at least one valid available 
communication system and returns to the question of determining the 
approximate location information (302).