Signal time of arrival position determining method for calculating cellular telephone billing charges

• US 5,758,288 A
• Filed: 01/31/1997
• Issued: 05/26/1998
• Est. Priority Date: 04/08/1992
• Status: Expired due to Term

• Current Assignee: Comcast MO Group Incorporated (Comcast Corporation)
• Original Assignee: MediaOne Group Inc. (Comcast Corporation)
• Inventors: Dunn, Michael Jeffrey, Foerster, Ronald Ernest, Reudink, Douglas Otto John, Feuerstein, Martin Jay, Atherly, Don Harold, Chuang, Ching, Vendetti, Dino John
• Primary Examiner(s): Hudspeth, David R.
• Assistant Examiner(s): RICHARDSON, SCO
• Application Number:
  US08/794,261
• Time in Patent Office: 480 Days
• Field of Search: 379/59, 379/58, 379/60, 342/357, 342/463, 342/450, 455/421, 455/422, 455/406, 455/407, 455/456, 455/440
• US Class Current: 455/456.5
• CPC Class Codes: G01S 5/10 Position of receiver fixed by co-ordinating a plurality of position lines defined by path-difference measurements , e.g. omega or decca systemsG01S5/12 takes precedence ; beacons and receivers cooperating therewith G01S1/306, G01S1/308
• CPC Class Codes: G01S 5/14 Determining absolute distances from a plurality of spaced points of known location
• CPC Class Codes: H04M 15/8033 location-dependent, e.g. business or home
• CPC Class Codes: H04M 15/8083 involving reduced rates or discounts, e.g. time-of-day reductions or volume discounts
• CPC Class Codes: H04M 2215/0184 involving reduced rates or discounts, e.g. time-of-day reductions, volume discounts, cell discounts, group billing, frequent calling destination(s) or user history list
• CPC Class Codes: H04M 2215/32 Involving wireless systems
• CPC Class Codes: H04M 2215/7435 Location dependent, e.g. Bussiness or home
• CPC Class Codes: H04W 4/02 Services making use of location information
• CPC Class Codes: H04W 4/24 Accounting or billing
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management

Abstract

A cellular telephone mobile unit position determining method which utilizes a plurality of range transceivers located at known fixed locations adapted to transmit approximately synchronized digital range signals. The method is especially adapted to determine the position of a cellular mobile unit within cellular service areas for determining billing charges and/or access restrictions. According to the invention, the fixed position range transceivers transmit range signals which are received by a mobile unit. The mobile unit determines either the time difference of arrival or absolute time of arrival of the range signals, which in turn is used to determine the mobile unit'"'"'s position for cellular billing and/or access restriction purposes. The range transceivers are operable to receive an error signal and correspondingly adjust the output of the next transmitted range signal so as to drive the detected synchronization error to approximately zero.

Claims

1. For use in a wireless telephone system that includes a computer having memory provided in electrical communication with a cell site transceiver that transmits and receives voice signals and control signals to and from a mobile telephone unit over one or more respective voice and primary control channels in order to provide wireless telephone service within a cell site coverage area, a method of providing predefined user zones for access restriction and billing purposes, comprising:

defining (1) by primary coordinate boundaries a user zone; and

(2) a plurality of ranging transceiver fixed locations and storing said coordinates and corresponding user zone in said computer memory;

at said plurality of ranging transceiver fixed locations, generating approximately synchronized digital range signals over one or more secondary control channels;

at a known location relative to the locations of said range transceivers, receiving said range signals by a primary receiver, determining the amount that each range signal deviates from system synchronization, and sending corresponding error signals over said secondary control channels to said range transceivers so as to more closely bring said transmitted range signals into synchronization;

receiving said range signals by said mobile unit over said secondary control channels;

determining the difference of arrival times of said received range signals in said mobile unit;

determining secondary coordinate values, from said difference of arrival times of the received range signals, defining the position of said mobile unit relative to said predetermined zone;

transmitting an electrical signal over said primary control channel for receipt by said cell site transceiver indicating whether said mobile unit is in or out of said predetermined zone; and

determining telephone service charges and/or access based on said determined mobile unit position and predetermined tariff and access tables.

2. The method of claim 1 further comprising adjusting a time stamp of the next transmitted range signal of each of said range transceivers in accordance with said determined synchronization error so as to simulate synchronization.

3. The method of claim 2 further comprising the step of adjusting the time stamp of the next range signal generated by each of said range transceivers in accordance with the last determined synchronization error of the corresponding range signals received by said primary receiver.

4. The method of claim 1 further comprising adjusting the output of the next transmitted range signal of each of said range transceivers in accordance with said determined synchronization error so as to drive said corresponding synchronization error to approximately zero.

5. The method of claim 1 wherein said range transceivers are each adapted to transmit multiple pulse sequences, said pulse sequences including an error portion corresponding to the approximate synchronization error of each range signals.

6. The method of claim 5 further comprising the step of adjusting the error portion of the next range signal generated by each of said range transceivers in accordance with the last determined synchronization error of the corresponding range signals received by said primary receiver.

7. The method of claim 1 wherein said plurality of ranging transceiver fixed locations are stored in said computer memory.

8. The method of claim 1 wherein said plurality of ranging transceiver fixed locations are encoded in said digital range signals.

9. For use in a wireless telephone system that includes a computer having memory provided in electrical communication with a cell site transceiver that transmits and receives voice signals and control signals to and from a mobile telephone unit over one or more respective voice and primary control channels in order to provide wireless telephone service within a cell site coverage area, a method of providing predefined user zones for access restriction and billing purposes, comprising:

defining (1) by primary coordinate boundaries a user zone; and

(2) a plurality of ranging transceiver fixed locations and storing said coordinates and corresponding user zone in said computer memory;

at said plurality of ranging transceiver fixed locations, generating approximately synchronized digital range signals over one or more secondary control channels;

at a known location relative to the locations of said range transceivers, receiving said range signals by a primary receiver, determining the amount that each range signal deviates from system synchronization, and sending corresponding error signals over said secondary control channels to said range transceivers so as to more closely bring said transmitted range signals into synchronization;

receiving said range signals by said mobile unit over said secondary control channels;

determining the absolute time of arrival of said received range signals, in said mobile unit

determining secondary coordinate values, from said absolute time of a rival of the received range signals, defining the position of said mobile unit relative to said predetermined zone;

transmitting an electrical signal over said primary control channel for receipt by said cell site transceiver indicating whether said mobile unit is in or out of said predetermined zone; and

determining telephone service charges and/or access based on said determined mobile unit position and predetermined tariff and access tables.

10. The method of claim 9 further comprising adjusting a time stamp of the next transmitted range signal of each of said range transceivers in accordance with said determined synchronization error so as to simulate synchronization.

11. The method of claim 10 further comprising the step of adjusting the time stamp of the next range signal generated by each of said range transceivers in accordance with the last determined synchronization error of the corresponding range signals received by said primary receiver.

12. The method of claim 9 further comprising adjusting the output of the next transmitted range signal of each of said range transceivers in accordance with said determined synchronization error so as to drive said corresponding synchronization error to approximately zero.

13. The method of claim 9 wherein said range transceivers are each adapted to transmit multiple pulse sequences, said pulse sequences including an error portion corresponding to the approximate synchronization error of each range signals.

14. The method of claim 13 further comprising the step of adjusting the error portion of the next range signal generated by each of said range transceivers in accordance with the last determined synchronization error of the corresponding range signals received by said primary receiver.

15. The method of claim 9 wherein said plurality of ranging transceiver fixed locations are stored in said computer memory.

16. The method of claim 9 wherein said plurality of ranging transceiver fixed locations are encoded in said digital range signals.