Method and apparatus for simultaneous radio and mobile frequency transition via “handoff to self”

• US 6,701,148 B1
• Filed: 12/21/1999
• Issued: 03/02/2004
• Est. Priority Date: 12/21/1999
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Wilson, James E., Carter, Daniel
• Primary Examiner(s): Chin, Vivian
• Assistant Examiner(s): Milord, Marceau
• Application Number:
  US09/468,551
• Time in Patent Office: 1,533 Days
• Field of Search: 455/436, 455/438, 455/450, 455/452, 455/437, 455/439, 455/442, 455/444, 455/422, 455/67.1, 370/331, 370/332
• US Class Current: 455/436
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point

Abstract

A cellular network having an radio frequency (RF) management capability includes a mobile switching center, at least one base station controller operative coupled to the mobile switching center, and at least one base station operatively coupled to the at least one base station controller. The at least one base station is for being operatively coupled with at least one mobile station for carrying out at least one mobile communications call. Lastly, a radio frequency manager is operatively coupled to the at least one base station, in conjunction with the at least one mobile station. The RF manager is further for managing a handoff upon the occurrence of a prescribed event, the handoff including a handoff-to-self via a simultaneous base station radio and mobile station frequency transition.

Claims

1. A cellular network having a radio frequency (RF) management capability, said network comprising:

a mobile switching center;

at least one base station controller operatively coupled to said mobile switching center;

at least one base station operatively coupled to said at least one base station controller, the at least one base station for being operatively coupled with at least one mobile station for carrying out at least one mobile communications call in a first cell; and

a radio frequency manager operatively coupled to said at least one base station and in conjunction with the at least one mobile station for managing a handoff upon the occurrence of a prescribed event, the handoff including a handoff to self operable to transition said mobile station and said base station from a first frequency to a second frequency while remaining operatively coupled, wherein the second frequency is selected without querying a second cell for frequency information.

2. The network of claim 1, wherein the frequency transition includes an automatic frequency plan transition.

3. The network of claim 2, wherein said radio frequency manager further includes:

means for determining a new frequency plan;

means for instructing prescribed base station radios of a given cell to change to a new channel number;

means for issuing handoff commands from the prescribed base station radios to all mobile stations on a respective radio;

means for tuning the prescribed base station radio to the new channel number; and

means for completing the handoff by the respective mobile stations to the new channel number while remaining operatively coupled to a same physical radio.

4. The network of claim 3, wherein said means for tuning the prescribed base station radio to the new channel number further includes means for transmitting at least one of the following selected from the group consisting of digital verification caller code (DVCC) and supervisory audio tone (SAT).

5. The network of claim 1, wherein the frequency transition includes an adaptive channel allocation/dynamic frequency association (ACA/DFA) noise event frequency transition.

6. The network of claim 5, wherein said radio frequency manager further includes:

means for detecting a prescribed level of severe noise during a DFA call and triggering an interference handoff in response thereto;

means for identifying a new clear channel using a prescribed DFA algorithm and instructing a prescribed base station radio to change to the new clear channel;

means for issuing handoff commands from the prescribed base station radio to all mobile stations on the radio;

means for tuning the prescribed base station radio to the new channel number; and

means for completing the handoff by the respective mobile stations to the new channel number while remaining operatively coupled to a same physical radio.

7. The network of claim 6, wherein means for tuning the prescribed base station radio to the new channel number further includes means for transmitting at least one of the following selected from the group consisting of digital verification caller code (DVCC) and supervisory audio tone (SAT).

8. The network of claim 1, wherein the frequency transition includes one of the following selected from the group consisting of an automatic frequency plan transition and an adaptive channel allocation/dynamic frequency association (ACA/DFA) noise event frequency transition.

9. The network of claim 8, wherein said radio frequency manager further includes:

means for determining a new frequency plan and, in response thereto, instructing prescribed base station radios of a given cell to change to a new channel number;

means for detecting a prescribed level of severe noise during a DFA call and triggering an interference handoff in response thereto, further including means for identifying a new clear channel using a prescribed DFA algorithm and, in response thereto, instructing a prescribed base station radio to change to the new clear channel;

means for issuing handoff commands from the prescribed base station radios to all mobile stations on a respective radio; and

means for tuning the prescribed base station radio to the new channel number; and

means for completing the handoff by the respective mobile stations to the new channel number while remaining operatively coupled to a same physical radio.

10. The network of claim 9, wherein means for tuning the prescribed base station radio to the new channel number further includes means for transmitting at least one of the following selected from the group consisting of digital verification caller code (DVCC) and supervisory audio tone (SAT).

11. A method of radio frequency (RF) management in a cellular network, said method comprising:

providing a mobile switching center;

providing at least one base station controller operatively coupled to the mobile switching center;

providing at least one base station operatively coupled to the at least one base station controller, the at least one base station for being operatively coupled with at least one mobile station via a first channel for carrying out at least one mobile communications call;

providing a radio frequency manager operatively coupled to the at least one base station and in conjunction with the at least one mobile station; and

managing a handoff upon the occurrence of a prescribed event, the handoff including using a handoff-to-self to switch directly from the first channel to a second channel via a simultaneous base station radio and mobile station frequency transition, wherein said mobile station remains operatively coupled via the second channel to said base station during and after the handoff to self.

12. The method of claim 11, wherein the frequency transition includes an automatic frequency plan transition.

13. The method of claim 12, wherein providing the radio frequency manager further includes:

determining a new frequency plan;

instructing prescribed base station radios of a given cell to change to a new channel number;

issuing handoff commands from the prescribed base station radios to all mobile stations on a respective radio;

tuning the prescribed base station radio to the new channel number; and

completing the handoff by the respective mobile stations to the new channel number while remaining operatively coupled to a same physical radio.

14. The method of claim 13, wherein tuning the prescribed base station radio to the new channel number further includes beginning the transmission of at least one of the following selected from the group consisting of digital verification caller code (DVCC) and supervisory audio tone (SAT).

15. The method of claim 11, wherein the frequency transition includes an adaptive channel allocation/dynamic frequency association (ACA/DFA) noise event frequency transition.

16. The method of claim 15, wherein providing the radio frequency manager further includes:

detecting a prescribed level of severe noise during a DFA call and triggering an interference handoff in response thereto;

identifying a new clear channel using a prescribed DFA algorithm and instructing a prescribed base station radio to change to the new clear channel;

issuing handoff commands from the prescribed base station radio to all mobile stations on the radio;

tuning the prescribed base station radio to the new channel number; and

completing the handoff by the respective mobile stations to the new channel number while remaining operatively coupled to a same physical radio.

17. The method of claim 16, wherein tuning the prescribed base station radio to the new channel number further includes beginning the transmission of at least one of the following selected from the group consisting of digital verification caller code (DVCC) and supervisory audio tone (SAT).

18. The method of claim 11, wherein the frequency transition includes one of the following selected from the group consisting of an automatic frequency plan transition and an adaptive channel allocation/dynamic frequency association (ACA/DFA) noise event frequency transition.

19. The method of claim 18, wherein providing the radio frequency manager further includes:

determining a new frequency plan and, in response thereto, instructing prescribed base station radios of a given cell to change to a new channel number;

detecting a prescribed level of severe noise during a DFA call and triggering an interference handoff in response thereto, further including identifying a new clear channel using a prescribed DFA algorithm and, in response thereto, instructing a prescribed base station radio to change to the new clear channel;

issuing handoff commands from the prescribed base station radios to all mobile stations on a respective radio;

tuning the prescribed base station radio to the new channel number; and

completing the handoff by the respective mobile stations to the new channel number while remaining operatively coupled to a same physical radio.

20. The method of claim 19, wherein tuning the prescribed base station radio to the new channel number further includes beginning the transmission of at least one of the following selected from the group consisting of digital verification caller code (DVCC) and supervisory audio tone (SAT).

21. A method for radio frequency transition using a handoff to self in a telecommunications network, said method comprising:

establishing a call between a base station and a mobile station using a first communications channel at a first frequency;

identifying a prescribed event signaling that the call should be transitioned from the first frequency to a second frequency; and

establishing a second communications channel at the second frequency by simultaneously transitioning the base station and the mobile station to the second frequency, wherein the base station and the mobile station remain operatively coupled during the transition, the transition enabling the base station to handoff the call from the first frequency to the second frequency without using another base station.

22. The method of claim 21 further including utilizing a frequency plan to determine the second frequency.

23. The method of claim 21 wherein the prescribed event is the detection of a predetermined level of noise on the first communications channel.

24. The method of claim 21 further including determining whether a level of noise of the second communications channel is below a predetermined threshold.