Mobile telecommunication device and method used for changing wireless communication between base stations of different kinds

• US 5,732,360 A
• Filed: 09/08/1995
• Issued: 03/24/1998
• Est. Priority Date: 09/08/1995
• Status: Expired due to Term

• Current Assignee: AT&T Mobility II LLC (AT&T, Inc.)
• Original Assignee: At & T Wireless Services and Atmel Corporation
• Inventors: Jarett, Keith, Williams, Roland E., Raffel, Michael A., Kibria, Masud, Nelson, Roderick, Lee, Tony S.
• Primary Examiner(s): Urban, Edward F.
• Application Number:
  US08/526,027
• Time in Patent Office: 928 Days
• Field of Search: 455/56.1, 455/33.1, 455/33.4, 455/54.1, 455/54.2, 455/89, 455/186.1, 455/426, 455/432, 455/433, 455/435, 455/552, 455/525, 379/58, 379/59
• US Class Current: 455/552.1
• CPC Class Codes: H04W 48/18 Selecting a network or a communication service
• CPC Class Codes: H04W 8/183 Processing at user equipment or user record carrier
• CPC Class Codes: H04W 84/105 PBS [Private Base Station] network H04W84/12 - H04W84/16 take precedence
• 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 remote unit has the ability to switch automatically from a public network to a non-public network comprising of private and residential base stations. In the preferred embodiment, the public network is characterized by cells with each cell having a unique identification signal. Initially, a first switchover from a public network to a non-public network requires the user to manually cause the switchover. The remote unit stores the first identification signal transmitted by the base station from which the remote unit traversed into the region covered by the non-public base station. In addition, the remote unit stores the identification signal associated with a cell of the public network previous to the current cell if the switchover occurred less than two (2) minutes from the exit of the previous cell. In this manner, the remote unit can adaptively learn as it traverses other possible paths from other cells into the region covered by the non-public base station.

Claims

1. A mobile telecommunicating device for communicating wirelessly with a plurality of base stations of a first kind, in a first communication protocol, and for communicating wirelessly with at least a base station of a second kind, in a second communication protocol, wherein each of said plurality of base stations of said first kind and said base station of said second kind transmits and receives wireless signals to and from a respective region, with a region of one base station of said first kind overlapping a region of said base station of said second kind, and wherein each of said plurality of base stations of said first kind transmits a distinctive identification signal, said device comprising:

means for receiving each of said distinctive identification signal in said first protocol, from each of said plurality of base stations of said first kind, as said mobile telecommunication device travels through the respective regions of said plurality of base stations of said first kind;

means for storing a first distinctive identification signal transmitted by said one base station of said first kind and for storing a previous distinctive identification signal, said previous distinctive identification signal being a distinctive identification signal received by said device within a predetermined time prior to a current distinctive identification signal received, said current distinctive identification signal received being a distinctive identification signal currently received by said device; and

means for comparing said distinctive identification signal received by said device to previously stored distinctive identification signals and to attempt to initiate communication in said second communication protocol in the event of a match.

2. The device of claim 1 further comprising:

timing means for measuring a predetermined period of time; and

wherein said storing means purges said previous distinctive identification signal in the event said device does not receive said current distinctive identification signal within a time period at least equal to said predetermined period of time.

3. The device of claim 2 wherein said storing means further stores a second distinctive identification signal, said second distinctive identification signal transmitted by a base station of said first kind, whose associated region overlaps said region of said one base station of said first kind, and wherein said comparing means further comprising:

means for comparing said current distinctive identification signal to said first distinctive identification signal, and for comparing said previous distinctive identification signal to said second distinctive identification signal, and in the event of a match in either comparison, attempt to initiate communication in said second communication protocol.

4. The device of claim 1 wherein said first communication protocol is in a first frequency.

5. The device of claim 1 wherein said second communication protocol is in a second frequency, different from said first frequency.

6. The device of claim 1 wherein said plurality of base stations of said first kind comprise a public carrier communication network.

7. The device of claim 6 wherein said base station of said second kind comprises a non-public communication network.

8. The device of claim 1 wherein said region of said base station of said second kind, overlapping with a plurality of regions of base stations of said first kind.

9. The device of claim 8 wherein said storing means further stores a second distinctive identification signal, said second distinctive identification signal transmitted by another base station of said first kind, whose associated region overlaps said region of said base station of said second kind.

10. The device of claim 9 wherein said comparing means further compares said distinctive identification signal received by said device to said second distinctive identification signal stored and to attempt to initiate communication with said base station of said second kind in the event of a match.

11. A method of changing wireless communication between a mobile unit and a first base station of a plurality of base stations of first kind, in a first communication protocol, and between said mobile unit and a base station of a second kind in a second communication protocol, wherein each of said plurality of base stations of said first kind and said base station of said second kind transmits and receives wireless signals to and from a respective region, with said region of said first base station of said first kind overlapping said region of said base station of said second kind, and wherein each of said plurality of base stations of said first kind transmits a distinctive identification signal, said method comprising:

storing by said mobile unit, through user activation, a first distinctive identification signal transmitted by said first base station of said first kind;

receiving by said mobile unit each of said distinctive identification signal in said first communication protocol, from each of said plurality of base stations of said first kind, as said mobile unit travels through the respective regions of said plurality of base stations of said first kind;

storing, by said mobile unit, a previous distinctive identification signal, said previous distinctive identification signal being a distinctive identification signal received by said mobile unit within a predetermined time prior to a current distinctive identification signal received, said current distinctive identification signal being a distinctive identification signal currently received by said mobile unit; and

comparing said distinctive identification signal received by said mobile unit to previously stored distinctive identification signals and to attempt to initiate communication in said second communication protocol in the event of a match.

12. The method of claim 11 further comprising:

measuring a predetermined period of time; and

purging said previous distinctive identification signal in the event said mobile unit does not receive said current distinctive identification signal within at least a time period equal to said predetermined period of time.

13. The method of claim 12 further comprising:

storing a second distinctive identification signal, said second distinctive identification signal transmitted by a base station of said first kind, whose associated region overlaps said region of said first base station of said first kind;

comparing said current distinctive identification signal to said first distinctive identification signal, and in the event of a match;

comparing said previous distinctive identification signal to said second distinctive identification signal; and

attempting to initiate communication in said second communication protocol, in the event of a match in either of said comparing steps.

14. The method of claim 11 wherein said first communication protocol is in a first frequency.

15. The method of claim 11 wherein said second communication protocol is in a second frequency, different from said first frequency.

16. The method of claim 11 wherein said plurality of base stations of said first kind comprise a public carrier communication network.

17. The method of claim 11 wherein said base station of said second kind comprises a non-public communication network.

18. The method of claim 11 wherein said region of said base station of said second kind, overlapping with a plurality of regions of base stations of said first kind.

19. The method of claim 18 wherein said storing step further stores a second distinctive identification signal, said second distinctive identification signal transmitted by a second base station of said first kind, whose associated region overlaps said region of said base station of said second kind.

20. The method of claim 19 wherein said comparing step further compares said distinctive identification signal received by said mobile unit to said second distinctive identification signal stored and to attempt to initiate communication with said base station of said second kind in the event of a match.

21. The method of claim 20 further comprising the step of

ranking said stored first and second distinctive identification signals based upon frequency of occurrence.

22. The method of claim 20 further comprising the step of

ranking said stored first and second distinctive identification signals based upon more recent occurrence.

23. The method of claim 22 further comprising the step of

determining a predetermined period of time;

and

purging a distinctive identification signal stored in said mobile unit in the event of absence of a match within said predetermined period of time.

24. A method of operating a portable communication device for switching communication between said device and two wireless networks, each of said networks transmitting a characteristic signal, said method comprising,

monitoring characteristic signals transmitted by one of said two wireless networks;

storing characteristic signals of said one network, when a user activates switching in communication from said one network to another of said two wireless networks;

communicating wirelessly with said one network, while monitoring characteristic signals thereof;

storing a previous distinctive identification signal, said previous distinctive identification signal being a distinctive identification signal monitored by said portable communication device within a predetermined time prior to a current distinctive identification signal being monitored, said current distinctive identification signal received being a distinctive identification signal currently received by said device

comparing said characteristic signals monitored while communicating with said one network with previously stored characteristic signals, and

attempting to initiate communication automatically with said another network in the event of a match in said comparing step.

25. The method of claim 24 further comprising:

measuring a predetermined period of time; and

purging said previous distinctive identification signal in the event said portable communication device does not receive said current distinctive identification signal within a time period at least equal to said predetermined period of time.

26. The method of claim 24 wherein communication with said first wireless network is in a first frequency.

27. The method of claim 26 wherein communication with said second wireless network is in a second frequency, different from said first frequency.

28. The method of claim 24 wherein said first wireless network is a public carrier communication network comprising a plurality of base stations each base station communicating within a cell.

29. The method of claim 28 wherein a plurality of cells of said first wireless network overlap said region of said second wireless network.

30. The method of claim 29 wherein each of said plurality of base stations of said first wireless network transmits a distinctive identification signal, with said characteristic signals being said distinctive identification signals.

31. The method of claim 24 wherein said second wireless network is a non-public communication network comprising a base station communicating within a region.