System and methods in a dual mode wireless system for transmitting rescan command based on detected network conditions

• US 6,456,858 B1
• Filed: 12/21/1998
• Issued: 09/24/2002
• Est. Priority Date: 12/21/1998
• Status: Expired due to Term

• Current Assignee: Bell Atlantic Mobile Systems Incorporated (Verizon Communications Inc.)
• Original Assignee: Verizon Wireless Inc. (Verizon Communications Inc.)
• Inventors: Streter, Cory W.
• Primary Examiner(s): Le, Thanh Cong
• Assistant Examiner(s): D AGOSTA, STEPHEN M
• Application Number:
  US09/215,787
• Time in Patent Office: 1,373 Days
• Field of Search: 455/439, 455/452, 455/553, 370/229
• US Class Current: 455/552.1
• CPC Class Codes: H04W 88/06 adapted for operation in multiple networks or having at least two operational modes, e.g. multi-mode terminals

Abstract

A dual-mode wireless telephone communications system, having a digital wireless communications system (e.g., CDMA) and a second wireless communications system, selectively outputs a rescan command from the digital wireless system to at least one selected dual-mode wireless telephone. The digital wireless communications system outputs the rescan command based on a detected traffic condition in the digital wireless system. The rescan command, output to the selected dual-mode wireless telephone via a digital wireless signaling channel, instructs the selected dual-mode wireless telephone to register with an alternative wireless communications system (e.g., AMPS) when the dual-mode wireless telephone is in an idle state. Hence, the digital wireless system can selectively limit access to the CDMA system by dual-mode telephones using proactive rescan commands that avoid the necessity of hard handoff or call transfer procedures normally encountered when initiating a wireless telephone call on the digital wireless communications system.

Claims

1. A method in a dual-mode wireless communications system having a digital wireless communications system overlying a second wireless communications system, the method comprising:

detecting a prescribed traffic condition in the digital wireless communications system; and

outputting a control command from the digital wireless communications system to at least one selected dual-mode wireless telephone, having registered with the digital wireless communications system, instructing the at least one selected dual-mode wireless telephone to register with the second wireless communications system based on the detected prescribed traffic condition if in an idle state.

2. The method of claim 1, wherein the step of detecting a prescribed traffic condition comprises detecting the prescribed traffic condition by a mobile telephone switching office.

3. The method of claim 2, wherein the outputting step comprises:

generating the control command in the mobile telephone switching office in response to the detection of the prescribed traffic condition; and

transmitting the control command from a selected digital wireless base station in communication with the dual-mode wireless telephone.

4. The method of claim 3, wherein the transmitting step includes transmitting the control command on a prescribed signaling channel.

5. The method of claim 2, wherein the step of detecting a prescribed traffic condition further includes detecting a facilities failure within the digital wireless communications system.

6. The method of claim 5, wherein the step of detecting a prescribed traffic condition further includes identifying the facilities failure as at least one of a blocking in the mobile telephone switching office and a failure in a trunk line in communication with the mobile telephone switching office.

7. The method of claim 2, wherein the step of detecting a prescribed traffic condition further comprises:

detecting base station blockage factors by a base station transceiver of the digital wireless communications system;

reporting the base station blockage factors to the mobile telephone switching office; and

determining the prescribed traffic condition in the mobile telephone switching office based on the reported base station blockage factors.

8. The method of claim 7, wherein the step of detecting base station blockage factors includes measuring at least one of an airlink interference overload and an airlink capacity overload by the base station transceiver on at least one of a forward link and reverse link.

9. The method of claim 7, wherein the step of detecting base station blockage factors includes detecting a hardware overload condition at the base station transceiver.

10. The method of claim 1, further comprising selecting the at least one selected dual-mode wireless telephone, from a plurality of dual-mode wireless telephones in communication with the digital wireless communications system, based on a corresponding prescribed service condition.

11. The method of claim 10, wherein the outputting step includes specifying a minimum time interval for registration with the second wireless communications system based on the corresponding prescribed service condition.

12. A method in a wireless communication system including dual-mode wireless telephones and a dual-mode communications system, having a first wireless communications system and a digital wireless communications system overlying the first wireless communication system, the method comprising:

establishing a first registration, between one of the dual-mode wireless telephones and the digital wireless communications system according to a prescribed digital wireless protocol;

detecting a prescribed traffic condition in the digital wireless communications system;

transmitting a control command through the digital wireless communications system to the one dual-mode wireless telephone, based on the detected prescribed traffic condition;

receiving the control command in the one dual-mode wireless telephone, while the one dual-mode wireless telephone is idle; and

in response to receiving the control command while idle, establishing a second registration, between the one dual-mode wireless telephone and the first wireless communications system according to a prescribed wireless protocol, and dropping the first wireless registration.

13. The method of claim 12, wherein the step of detecting a prescribed traffic condition comprises detecting the prescribed traffic condition by a mobile telephone switching office.

14. The method of claim 13, wherein the step of detecting a prescribed traffic condition further includes detecting a facilities failure within the digital wireless communications system.

15. The method of claim 13, wherein the step of detecting a prescribed traffic condition further comprises:

detecting base station blockage factors by a base station transceiver of the digital wireless communications system;

reporting the base station blockage factors to the mobile telephone switching office; and

determining the prescribed traffic condition in the mobile telephone switching office based on the reported base station blockage factors.

16. The method of claim 12, further comprising:

selecting the one dual-mode wireless telephone, from a plurality of dual-mode wireless telephones in communication with the digital wireless communications system, based on a corresponding prescribed service condition; and

generating the control command by including a minimum rescan interval specifying a minimum time interval for registering with the second wireless communications system, based on the prescribed service condition.

17. The method of claim 16, further comprising maintaining, by the one dual-mode wireless telephone, the second wireless registration for the minimum time interval before attempting to establish another registration with the digital wireless communications system.

18. A dual-mode wireless communications system comprising:

a first wireless telephone communications system configured for wireless telephone communications in prescribed coverage areas according to a first wireless protocol; and

a digital wireless telephone communications system configured for communication with dual mode wireless telephones registered in the prescribed coverage areas according to a digital wireless protocol,

the digital wireless telephone communications system including a mobile telephone switching office configured for outputting a rescan instruction to a selected group of registered dual mode wireless telephones, instructing idle ones of the selected group to register with the first wireless telephone communications system, in response to a detection of a prescribed traffic condition in the digital wireless telephone communications system.

19. The system of claim 18, wherein the mobile telephone switching office includes a subscriber profile register for storing subscriber priority information for each of the dual mode telephones, the mobile telephone switching office determining the selected group based on the subscriber priority information identifying a corresponding priority class.

20. The system of claim 19, wherein the mobile telephone switching office specifies in the rescan instruction a minimum time interval before the selected group can establish another wireless link with the digital communications system, based on the priority class for the selected group.

21. The system of claim 18, wherein the mobile telephone switching office detects the prescribed traffic condition as a facilities failure within the digital wireless communications system.

22. The system of claim 21, wherein the mobile telephone switching office detects the facilities failure as one of a blocking in the mobile telephone switching office and a failure in a trunk line in communication with the mobile telephone switching office.

23. The system of claim 18, wherein the digital wireless telephone communications system further includes a base station transceiver for communication with at least a group of the dual-mode wireless telephones on an airlink, the base station transceiver detecting the prescribed traffic condition as one or more detected base station blockage factors, including at least one of an airlink interference overload and an airlink capacity overload, and reporting each detected base station blockage factor to the mobile telephone switching office.

24. A dual-mode wireless telephone comprising:

a digital wireless transceiver configured for detecting a digital communications system and in response registering for digital communication therewith according to a digital wireless protocol;

a second wireless transceiver configured for selectively registering for wireless communications with a second communications system according to a second wireless protocol; and

a controller configured for controlling the digital wireless transceiver to terminate a registration with the digital communications system and activating the second wireless transceiver to initiate a registration with the wireless communications system in response to reception of a rescan command via the digital communication system during an idle telephone state.

25. The dual-mode wireless telephone of claim 24, wherein the controller controls the digital wireless transceiver to establish a new registration with the digital communications system a prescribed time interval after establishment of the wireless communications link in response to the reception of the rescan command.

26. The dual-mode wireless telephone of claim 25, wherein the controller obtains the prescribed time interval from the rescan command.

27. In a dual-mode wireless communications system having a digital first wireless communications system overlying a second wireless communications system, a traffic off-load method comprising:

detecting a prescribed traffic condition in the digital first wireless communications system;

in response to the detection of the prescribed traffic condition, selecting a dual-mode wireless telephone that has registered with the digital first wireless communications system; and

transmitting a control command from the digital wireless communications system instructing the selected dual-mode wireless telephone to register with the second wireless communications system when idle.