Paging system with adaptive monitoring schedule and method of operation thereof

• US 5,721,534 A
• Filed: 11/02/1995
• Issued: 02/24/1998
• Est. Priority Date: 11/02/1995
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Olds, Keith Andrew, Gregg, Ralph Charles, Smith, Patrick O'Connor
• Primary Examiner(s): Horabik, Michael
• Assistant Examiner(s): Beaulieu, Yonel
• Application Number:
  US08/552,159
• Time in Patent Office: 845 Days
• Field of Search: 340/825.44, 340/825.03, 340/825.47, 455/33.1, 455/33.4, 455/12.1, 455/13.3, 379/57, 379/58, 379/59, 370/313, 370/326
• US Class Current: 340/7.38
• CPC Class Codes: H04B 7/18567 Arrangements for providing additional services to the basic mobile satellite telephony service
• CPC Class Codes: H04W 84/022 One-way selective calling networks, e.g. wide area paging

Abstract

A satellite-based, world-wide cellular messaging system (5) transmits paging messages to pagers (2) via multiple beams. A pager (2) monitors multiple beams, recording the schedules for each beam, and by combining the schedules for multiple beams, ultimately determines which frames in the message groups to monitor for messages. As propagation characteristics degrade, an adaptive method refines the criteria for including frames into a monitoring schedule.

Claims

1. In a satellite paging system wherein a satellite projects a plurality of overlapping beams, each of said plurality of overlapping beams encompassing a plurality of logical delivery areas, each of said plurality of logical delivery areas being an addressable geographic area, said plurality of overlapping beams having combined paging schedules transmitted therein designating a plurality of subsequent messaging frames delivering paging messages to said plurality of logical delivery areas encompassed by one of said plurality of overlapping beams, and wherein a first portion of said plurality of overlapping beams encompasses one of said plurality of logical delivery areas, and wherein said combined paging schedules of a second portion of said first portion of said plurality of overlapping beams comprise replicated entries of said messaging frames designating said plurality of overlapping beams suitable for delivering said paging message to one of said plurality of logical delivery areas, a method for generating an adaptive pager monitoring schedule from reception of a third portion of said plurality of overlapping beams exceeding a signal quality threshold, reception of said third portion depending on propagation characteristics between said satellite and a pager, said method comprising the steps of:

generating an adaptive ratio from a first quantity of said third portion of said plurality of overlapping beams and a second quantity of said second portion of said plurality of overlapping beams, said adaptive ratio being a criteria for selecting entries for said adaptive pager monitoring schedule;

scaling a fixed threshold for inclusion into said adaptive pager monitoring schedule using said adaptive ratio to generate an adaptive threshold for inclusion; and

when entries in said combined paging schedules of said third portion of said plurality of overlapping beams match for at least said adaptive threshold for inclusion, including said entries in said adaptive pager monitoring schedule.

2. A method as recited in claim 1, further comprising:

in said generating step, said adaptive ratio being a quotient of said first quantity of said third portion of said plurality of overlapping beams and said second quantity of said second portion of said plurality of overlapping beams; and

in said scaling step, said adaptive threshold for inclusion being rounded to a nearest integer value.

3. A method as recited in claim 1, wherein said generating step comprises the steps of:

retrieving a stored table from said pager, said stored table defining incremental ratios defined by said system;

indexing said stored table using said first quantity of said third portion of said plurality of overlapping beams and said second quantity of said second portion of said plurality of overlapping beams; and

generating an adaptive ratio for selecting entries for said adaptive pager monitoring schedule.

4. A method as recited in claim 1, wherein when both said first quantity of said third portion of said plurality of overlapping beams and said second quantity of said second portion of said plurality of overlapping beams is greater than a constant integer,

said generating step comprises the step of, generating said adaptive ratio as a difference between said first quantity of said third portion of said plurality of overlapping beams and said constant integer;

and

said scaling step comprises the step of substituting said adaptive ratio for said fixed threshold for inclusion into said adaptive pager monitoring schedule to generate said adaptive threshold for inclusion.

5. A method as recited in claim 1, wherein when said first quantity of said third portion of said plurality of overlapping beams is less than or equal to a constant integer,

said generating step comprises the step of, defining said adaptive ratio to be one to allow inclusion of all of said entries in said combined paging schedules, and

said scaling step comprises the step of substituting said adaptive ratio for said fixed threshold for inclusion into said adaptive pager monitoring schedule to generate said adaptive threshold for inclusion.

6. A pager employing an adaptive pager monitoring schedule for use in a satellite paging system wherein a satellite projects a plurality of overlapping beams, each of said plurality of overlapping beams encompassing a plurality of logical delivery areas, each of said plurality of logical delivery areas being an addressable geographic area, each of said plurality of overlapping beams having a combined paging schedule transmitted therein designating a plurality of subsequent messaging frames delivering paging messages to said plurality of logical delivery areas encompassed by one of said plurality of overlapping beams, and wherein a first portion of said plurality of overlapping beams encompasses one of said plurality of logical delivery areas, and wherein said combined paging schedules of a second portion of said first portion of said plurality of overlapping beams comprise replicated entries of said messaging frames designating said plurality of overlapping beams suitable for delivering said paging message to one of said plurality of logical delivery areas, said pager comprising:

a receiver for receiving said third portion of said plurality of overlapping beams comprising said combined paging schedule;

a memory for storing said combined paging schedule, said second quantity of said second portion of said plurality of overlapping beams, a fixed threshold for inclusion into said adaptive pager monitoring schedule;

a battery for providing power to said pager; and

a processor coupled to said memory, said processor generating an adaptive ratio from a first quantity of said third portion of said plurality of overlapping beams and a second quantity of said second portion of said plurality of overlapping beams, said adaptive ratio being a criteria for selecting entries for said adaptive pager monitoring schedule,

scaling a fixed threshold for inclusion into said adaptive pager monitoring schedule using said adaptive ratio to generate an adaptive threshold for inclusion, and

when entries in said combined paging schedules of said third portion of said plurality of overlapping beams match for at least said adaptive threshold for inclusion, including said entries in said adaptive pager monitoring schedule.

7. A pager as recited in claim 6, wherein said processor further comprises:

a means for generating a quotient of said first quantity of said third portion of said plurality of overlapping beams and said second quantity of said second portion of said plurality of overlapping beams; and

a means for scaling said adaptive threshold for inclusion and rounding to a nearest integer value.

8. A pager as recited in claim 6, further comprising:

said memory further comprising a means for storing a stored table, said stored table defining incremental ratios defined by said system; and

said processor further comprising a means for retrieving a stored table from said pager, said stored table defining incremental ratios defined by said system,

indexing said stored table using said first quantity of said third portion of said plurality of overlapping beams and said second quantity of said second portion of said plurality of overlapping beams, and

generating an adaptive ratio for selecting entries for said adaptive pager monitoring schedule.

9. A pager as recited in claim 6, said processor further comprising:

when both said first quantity of said third portion of said plurality of overlapping beams and said second quantity of said second portion of said plurality of overlapping beams is greater than a constant integer,

a means for generating said adaptive ratio as a difference between said first quantity of said third portion of said plurality of overlapping beams and said constant integer; and

a means for substituting said adaptive ratio for said fixed threshold for inclusion into said adaptive pager monitoring schedule to generate said adaptive threshold for inclusion.

10. A pager as recited in claim 6, said processor further comprising:

when said first quantity of said third portion of said plurality of overlapping beams is less than or equal to a constant integer,

a means for defining said adaptive ratio to be one to allow inclusion of all of said entries in said combined paging schedules; and

a means for substituting said adaptive ratio for said fixed threshold for inclusion into said adaptive pager monitoring schedule to generate said adaptive threshold for inclusion.