Communication system with a mobile terminal supporting mobile assisted signal strength measurements for a plurality of networks and methods for operating the same

• US 6,526,279 B1
• Filed: 08/11/1999
• Issued: 02/25/2003
• Est. Priority Date: 08/11/1999
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W.
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Gesesse, Tilahun
• Application Number:
  US09/372,552
• Time in Patent Office: 1,294 Days
• Field of Search: 455/434, 455/435, 455/436, 455/437, 455/442, 455/443, 455/447, 455/448, 455/453, 455/550, 455/444, 455/439, 455/67.1
• US Class Current: 455/437
• CPC Class Codes: H04W 36/0066 of control information between different types of networks in order to establish a new radio link in the target network
• CPC Class Codes: H04W 36/0083 Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
• CPC Class Codes: H04W 36/0085 Hand-off measurements
• 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

Communication systems and methods are provided allowing a single mode mobile terminal to support mobile assisted signal strength measurement operations in both a fixed frequency reuse based communication network and an adaptive channel allocation based communication network. Candidate base station signal strength measurements are requested by a fixed frequency reuse type network, measured by the mobile terminal and provided to the fixed frequency reuse type network which is seeking to identify a strongest signal for mobile assisted handover operations. In addition, interference signal strength measurements are requested by an adaptive channel allocation type network, measured by the mobile terminal and provided to the adaptive channel allocation type network by the mobile terminal. No redundant circuitry is required in the mobile terminal. Instead, the mobile terminal executes the same operations using the same hardware regardless of whether the requested measurement is of a candidate signal strength or an interference signal.

Claims

1. A method for communicating between a mobile terminal and both a first wireless communication network and a second wireless communication network, the method comprising the following steps performed by the mobile terminal:

receiving over a control channel of the first wireless communication network an identification of a candidate channel for handoff;

determining an associated signal strength of the candidate channel;

transmitting the determined associated signal strength of the candidate channel to the first wireless communication network;

receiving over a control channel of the second wireless communication network an identification of a plurality of interference channels;

determining associated signal strengths for the plurality of interference channels; and

transmitting the determined associated signal strengths of the plurality of interference channels to the second wireless communication network.

2. The method of claim 1 wherein the step of receiving an identification of a candidate channel comprises the step of receiving an identification of a plurality of candidate channels corresponding to channels used by selected base stations of the first wireless communication system and wherein the step of determining an associated signal strength of the candidate channel comprises the step of determining associated signal strengths of the plurality of candidate channels and wherein the step of transmitting the determined associated signal strength of the candidate channel comprises the step of transmitting the associated signal strengths of the plurality of candidate channels.

3. The method of claim 2 wherein the selected base stations are base stations in the vicinity of a base station of the first wireless communication network which transmitted the identification of a plurality of candidate channels received by the mobile terminal.

4. A method according to claim 3 wherein the first wireless communication network is a GSM network using at least one of fixed frequency re-use or frequency hopping.

5. The method of claim 2 wherein the step of receiving an identification of a plurality of interference channels comprises the step of receiving an identification of a plurality of interference channels corresponding to channels allocated to the second wireless communication network which are currently unused by at least one selected base station of the second wireless communication network.

6. The method of claim 5 wherein said at least one selected base station includes a base station of the second wireless communication network which transmitted the identification of a plurality of interference channels received by the mobile terminal.

7. The method of claim 6 wherein the at least one selected base station of the second wireless communication network comprise base stations in the vicinity of the base station of the second wireless communication network which transmitted the identification of a plurality of interference channels received by the mobile terminal.

8. The method of claim 7 wherein the second wireless communication network is a GSM network using adaptive channel allocation and the first wireless communication network is a GSM network using at least one of fixed frequency re-use or frequency hopping.

9. The method of claim 7 wherein the receiving steps are carried out using a common receiver of the mobile terminal and the determining steps are carried out using a common signal strength measurement circuit of the mobile terminal and the transmitting steps are carried out using a common transmitter of the mobile terminal.

10. The method of claim 2 further comprising the following steps performed by the first wireless communication network:

transmitting the identification of a plurality of candidate channels;

receiving the transmitted associated signal strengths; and

selecting one of the selected base stations of the first wireless communication network to provide communication support for the mobile terminal based on the received associated signal strengths.

11. The method of claim 10 wherein the step of selecting comprises the step of selecting a one of the selected base stations of the first wireless communication network having the strongest associated signal strength to provide communications service for the mobile terminal.

12. The method of claim 10 further comprising the following steps performed by the second wireless communication network:

transmitting the identification of a plurality of interference channels;

receiving the transmitted associated signal strengths of the plurality of interference channels; and

selecting a channel of the second wireless communication network to provide communications service for the mobile terminal based on the received associated signal strengths of the plurality of interference channels.

13. A communication system, comprising:

a first wireless communication network comprising;

a plurality of base stations;

means for transmitting an identification of a plurality of candidate channels associated with the plurality of base stations;

means for receiving associated signal strengths of the plurality of candidate channels from a mobile terminal; and

means for selecting one of the plurality of base stations of the first wireless communication network to provide communication support for the mobile terminal based on the received associated signal strengths of the plurality of candidate channels; and

a second wireless communication network comprising;

means for transmitting an identification of a plurality of interference channels;

means for receiving associated signal strengths of the plurality of interference channels from the mobile terminal; and

means for selecting a channel of the second wireless communication network to provide communication support for the mobile terminal based on the received associated signal strengths of the plurality of interference channels; and

a mobile terminal comprising;

means for receiving over a control channel of the first wireless communication network the identification of a plurality of candidate channels associated with the plurality of base stations;

means for determining the associated signal strengths of the plurality of candidate channels;

means for transmitting the determined associated signal strengths of the plurality of candidate channels to the first wireless communication network;

means for receiving over a control channel of the second wireless communication network the identification of a plurality of interference channels;

means for determining the associated signal strengths of the plurality of interference channels; and

means for transmitting the associated signal strengths of the plurality of interference channels to the second wireless communication network.

14. The system of claim 13 wherein the means for receiving over a control channel of the first wireless communication network and the means for receiving over a control channel of the second wireless communication network are a common receiver and wherein the means for determining an associated signal strength of the candidate channel and the means for determining associated signal strengths for the plurality of interference channels are a common signal strength measurement circuit and wherein the means for transmitting the determined associated signal strength of the candidate channel and the means for transmitting the determined associated signal strengths of the plurality of interference channels are a common transmitter.

15. The system of claim 14 wherein the means for receiving an identification of a candidate channel comprises means for receiving an identification of a plurality of candidate channels corresponding to channels used by selected base stations of the first wireless communication system and wherein the means for determining an associated signal strength of the candidate channel comprises means for determining associated signal strengths of the plurality of candidate channels and wherein the means for transmitting the determined associated signal strength of the candidate channel comprises means for transmitting the associated signal strengths of the plurality of candidate channels.

16. The system of claim 15 wherein the selected base stations are base stations in the vicinity of a base station of the first wireless communication network which is providing communications service to the mobile terminal.

17. The system of claim 15 wherein the means for receiving an identification of a plurality of interference channels comprises means for receiving an identification of a plurality of interference channels corresponding to channels allocated to the second wireless communication network which are currently unused by at least one selected base station of the second wireless communication network.

18. The method of claim 17 wherein said at least one selected base station includes a base station of the second wireless communication network which transmitted the identification of a plurality of interference channels received by the mobile terminal.

19. The system of claim 18 wherein the at least one selected base station of the second wireless communication network comprises base stations in the vicinity of the base station of the second wireless communication network which transmitted the identification of a plurality of interference channels received by the mobile terminal.

20. The system of claim 19 wherein the means for selecting one of the selected base stations of the first wireless communication network comprises means for selecting a one of the selected base stations of the first wireless communication network having the strongest associated signal strength to provide communications service for the mobile terminal.

21. The system of claim 20 wherein the second wireless communication network is a GSM network using adaptive channel allocation and the first wireless communication network is a GSM network using at least one of fixed frequency re-use or frequency hopping.