Statistically robust traffic modeling method and apparatus

• US 5,594,940 A
• Filed: 12/22/1994
• Issued: 01/14/1997
• Est. Priority Date: 12/22/1994
• Status: Expired due to Term

• Current Assignee: CDC Propriete Intellectuelle
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Peterson, Kenneth M., Cutler, Jr., Victor H., Davieau, Gerald J.
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): BANKS HAROLD, MARSHA DENISE
• Application Number:
  US08/361,402
• Time in Patent Office: 754 Days
• Field of Search: 455/3.2, 455/33.1, 455/34.2, 455/12.1, 455/62, 455/63, 455/67.1, 455/89, 370/95.1, 370/95.3, 370/97, 370/75, 364/514 C
• US Class Current: 455/429
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection
• CPC Class Codes: H04W 16/04 Traffic adaptive resource partitioning
• CPC Class Codes: H04W 16/22 Traffic simulation tools or models

Abstract

A method and apparatus for controlling communication channel access in a communication system (10) determines channel allocations (106) which represent limits on communication channel access and conforms operations of the system (10) to the channel allocations. The channel allocations are determined by dividing a surface which emanates signals from communication units (26) into elemental areas, collecting past traffic data (102) describing past communication channel usage by the communication units (26) located in the elemental areas, generating a traffic model (104) for a future time interval based on the past traffic data, and determining the channel allocations (106) based on the traffic model.

Claims

1. A method for using a statistically robust traffic model to control access of communication units to communication channels in a communication system comprising the steps of:

a) dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein an elemental area is defined by a geographical region, and an area defined by a cell comprises a set of elemental areas;

b) collecting traffic data describing past and present communication channel usage by the communication units located in the set of elemental areas;

c) generating a statistically robust traffic model based on the traffic data within the set of elemental areas by combining the traffic data of elemental areas comprising the cell;

d) determining channel allocations based on the statistically robust traffic model; and

e) allowing access to the communication channels based on the channel allocations determined using the statistically robust traffic model.

2. The method as claimed in claim 1, wherein step b) comprises the steps of:

b1) determining call attempts during a particular time interval;

b2) determining the elemental areas in which the communication units making the call attempts are located; and

b3) collecting the traffic data as a totality of the call attempts for each of the elemental areas during the particular time interval.

3. The method as claimed in claim 1, wherein step c) comprises the steps of:

c1) determining past numbers of calls within the elemental areas during past time increments based on the traffic data;

c2) associating locations of cells at future times with sets of the elemental areas;

c3) predicting estimates of future numbers of calls based on the past numbers of calls and the locations of cells; and

c4) generating the statistically robust traffic model based on the estimates of future numbers of calls.

4. The method as claimed in claim 3, wherein the communication system comprises satellites which project the cells which can be divided into time-dependent sets of elemental areas onto the surface, the method further comprising the step of transmitting the channel allocations to the satellites.

5. The method as claimed in claim 1, wherein the communication system comprises satellites which project cells which can be divided into time-dependent sets of elemental areas onto the surface, and wherein step e) comprises the steps of:

e1) transmitting the channel allocations to the satellites; and

e2) allowing the communication units to use the communication channels provided in the cells up to a number not exceeding the channel allocations.

6. A method for using a statistically robust traffic model for controlling access of communication units to communication channels in a communication system comprising the steps of:

a) dividing a surface into elemental areas, on which surface the communication units emanate signals,

b) collecting traffic data describing past communication channel usage by the communication units located in the elemental areas;

c) generating a traffic model based on the traffic data by determining past numbers of calls within the elemental areas during past time increments based on the traffic data, associating locations of cells at future times with future sets of the elemental areas, predicting estimates of future numbers of calls based on the past numbers of calls and the past locations of cells by computing a mean number of calls using a first equation;

##EQU9## where L is a limit and ρ

_l is a call arrival rate divided by a service rate, and generating the statistically robust traffic model based on the estimates of future numbers of calls;

d) determining channel allocations based on the statistically robust traffic model; and

e) allowing access to the communication channels based on the channel allocations determined using the statistically robust traffic model.

7. The method as claimed in claim 6, wherein step d) comprises the steps of:

d1) computing a standard deviation of the mean number of calls using a second equation;

##EQU10## and d2) determining the channel allocations using a third equation;

##EQU11## where "a" is an arbitrary number.

8. A method for using a statistically robust traffic model to control access of communication units to communication channels performed by a satellite comprising the steps of:

a) receiving channel allocations from a control facility which have been calculated by dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein an elemental area is a geographical area and a cell comprises a set of the elemental areas, collecting traffic data describing past communication channel usage by the communication units located in the elemental areas, generating a statistically robust traffic model for a future time interval based on the traffic data, and determining the channel allocations based on the statistically robust traffic model;

b) storing the channel allocations; and

c) allowing the communication units to use the communication channels up to the channel allocations during the future time interval.

9. A method of accessing communication channels performed by a communication unit in a communication system comprising the steps of:

a) attempting to use a communication channel provided by a satellite; and

b) using the communication channel when use would not exceed channel allocations stored in the satellite, where the channel allocations are calculated by dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein an elemental area is a geographical area and a cell comprises a set of the elemental areas, collecting traffic data describing past communication channel usage by the communication units which have been positioned in an elemental area, generating a statistically robust traffic model for a future time interval based on the traffic data, and determining the channel allocations using the statistically robust traffic model.

10. The method as claimed in claim 9 further comprising the step of transmitting location information which positions the communication unit in an elemental area to the satellite when an attempt to use the communication channel has been made.

11. A method for using a statistically robust traffic model to control access of communication units to communication channels in a communication system, the method performed by a control facility and comprising the steps of:

a) dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein a cell comprises a set of the elemental areas and an elemental area is a geographic area on the surface;

b) collecting traffic data describing past communication channel usage by the communication units located in the elemental areas;

c) generating a traffic model based on the traffic data;

d) determining channel allocations based on the traffic model; and

e) transmitting the channel allocations to satellites which provide the communication channels and allow access to the communication channels based on the channel allocations.

12. A satellite comprising:

a down-link receiver for receiving channel allocations which have been calculated by dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein a cell comprises a set of the elemental areas and an elemental area is a geographic area on the surface, collecting traffic data describing past communication channel usage by the communication units located in the elemental areas, generating a statistically robust traffic model for a future time interval based on the traffic data, and determining the channel allocations based on the statistically robust traffic model;

a controller coupled to the down-link receiver for conforming access to communication channels according to the channel allocations during the future time interval;

a transmitter coupled to the controller for providing the communication channels to the communication units; and

a memory device coupled to the controller for storing the channel allocations.

13. A communication unit comprising:

a processor for attempting to use a communication channel provided by a satellite, and using the communication channel when use would not exceed channel allocations stored in the satellite, where the channel allocations have been calculated by dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein a cell comprises a set of the elemental areas and an elemental area is a geographic area on the surface, collecting traffic data describing past communication channel usage by the communication units located in the elemental areas, generating a traffic model for a future time interval based on the traffic data, and determining the channel allocations based on the traffic model; and

a transmitter coupled to the processor for transmitting location information to the satellite which is accurate enough to position the communication unit within an elemental area when an attempt to use the communication channel has been made.

14. A control facility comprising:

a controller for dividing a surface into elemental areas, on which surface the communication units emanate signals, wherein a cell comprises a set of the elemental areas and an elemental area is a geographic area on the surface, for collecting traffic data describing past communication channel usage by the communication units located in the elemental areas, for generating a statistically robust traffic model based on the traffic data from the set of elemental areas, and for determining channel allocations based on the statistically robust traffic model; and

an interface unit coupled to the controller for transmitting the channel allocations to satellites.