Mobile station and base station

• US 6,757,550 B1
• Filed: 09/08/2000
• Issued: 06/29/2004
• Est. Priority Date: 09/08/1999
• Status: Expired due to Fees

• Current Assignee: Kyocera Corporation
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Harada, Shigeki, Yoneyama, Masayuki
• Primary Examiner(s): APPIAH, CHARLES NANA
• Application Number:
  US09/658,270
• Time in Patent Office: 1,390 Days
• Field of Search: 455/436, 455/437, 455/438, 455/439, 455/440, 455/441, 455/442, 455/445, 455/444, 455/525, 455/524, 370/331, 370/332, 370/333, 375/346
• US Class Current: 455/525
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 56/0085 detecting a given structure in the signal
• CPC Class Codes: H04W 72/044 based on the type of the allocated resource
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 76/10 Connection setup

Abstract

A mobile station that selects one of a plurality of base stations according to electric field strengths of signals transmitted on control channels corresponding to the plurality of base stations, and establishes first a link and then a call connection with the selected base station on a traffic channel that is assigned via a control channel corresponding to the selected base station, the mobile station including: a measuring unit for measuring an electric field strength of a signal on the traffic channel when a link operation is performed to establish the link for the traffic channel; and a judging unit for judging whether the link operation should be continued according to the measured electric field strength.

Claims

1. A mobile station that selects one of a plurality of base stations according to electric field strengths of signals transmitted on control channels corresponding to the plurality of base stations, and establishes first a link and then a call connection with the selected base station on a traffic channel that is assigned via a control channel corresponding to the selected base station,

the mobile station comprising:

a measuring means for measuring an electric field strength of a signal on the traffic channel when a link operation is performed to establish the link for the traffic channel; and

a judging means for judging whether the link operation should be continued according to the measured electric field strength,

wherein the measuring means measures the electric field strength by calculating an average of electric field strengths measured in a plurality of slots, and each of the electric field strengths comprises first and second signal levels, the first signal level being determined by a reception signal received from the selected base station, and the second signal level being a noise level and determined by no reception signal received from the selected base station.

2. The mobile station of claim 1,

wherein when the measured electric field strength is not more than a predetermined value, the judging means judges that the link operation should be terminated.

3. The mobile station of claim 2 newly selects one of the plurality of base stations and requests the newly selected base station to assign a traffic channel if the judging means has judged that the link operation should be terminated.

4. The mobile station of claim 1,

wherein the measured electric field strength includes a signal level and a noise level, the signal level being a reception signal level when a signal is received from the selected base station on the traffic channel, and the noise level being a reception signal level when no signal is received from the selected base station on the traffic channel, and

the judging means judges that the link operation should be terminated if the signal level is not more than a first threshold value or a difference between the signal level and the noise level is not more than a second threshold value.

5. The mobile station of claim 4 newly selects one of the plurality of base stations and request the newly selected base station to assign a traffic channel if the judging means has judged that the link operation should be terminated.

6. A mobile station that selects one of a plurality of base stations according to electric field strengths of signals transmitted on control channels corresponding to the plurality of base stations, and establishes first a link and then a call connection with the selected base station on a traffic channel assigned by the selected base station,

the mobile station comprising:

a requesting means for issuing a traffic channel assignment request to the selected base station on a control channel corresponding to the selected base station;

a measuring means for measuring, after the traffic channel is assigned by the selected base station, an electric field strength of a link establishment signal transmitted from the selected base station on the traffic channel;

a judging means for judging whether the measured electric field strength of the link establishment signal is not more than a threshold value; and

a control means for terminating, if the judging means has judged that the measured electric field strength of the link establishment signal is not more than the threshold value, a link operation that establishes the link for the traffic channel and having the requesting means reissue the traffic channel assignment request on either the control channel corresponding to the selected base station or a control channel corresponding to a newly selected base station,

wherein the measuring means measures the electric field strength by calculating an average of electric field strengths measured in a plurality of slots, and each of the electric field strengths comprises first and second signal levels, the first signal level being determined by a reception signal received from the selected base station, and the second signal level being a noise level and determined by no reception signal received from the selected base station.

7. The mobile station of claim 6,

wherein the measuring means measures a noise level, which is a reception signal level when no signal is received from the selected base station on the traffic channel,

the judging means judges whether a difference between the measured electric field strength of the link establishment signal and the noise level is less than a second threshold value, and

the control means has the requesting means reissues the traffic channel assignment request if the difference is less than the second threshold value.

8. A base station that assigns a traffic channel to a mobile station and establishes first a link and then a call connection with the mobile station on the traffic channel, comprising:

a measuring means for measuring an electric field strength of a signal on the traffic channel when a link operation is performed to establish the link for the traffic channel; and

a judging means for judging whether the link operation should be continued according to the measured electric field strength,

wherein the measuring means measures the electric field strength by calculating an average of electric field strengths measured in a plurality of slots, and each of the electric field strengths comprises first and second signal levels, the first signal level being determined by a reception signal received from the selected base station, and the second signal level being a noise level and determined by no reception signal received from the selected base station.

9. The base station of claim 8,

wherein the measured electric field strength includes a signal level and a noise level, the signal level being a reception signal level when a signal is received from the mobile station on the traffic channel, and the noise level being a reception signal level when no signal is received from the mobile station on the traffic channel, and

the judging means judges that the link operation should be terminated if the signal level is not more than a first threshold value or a difference between the signal level and the noise level is not more than a second threshold value.

10. A base station that assigns a traffic channel to a mobile station in response to a traffic channel assignment request transmitted from the mobile station on a control channel, and establishes a link with the mobile station on the traffic channel,

the base station comprising:

a measuring means for measuring an electric field strength of a link establishment signal transmitted from the mobile station on the traffic channel;

a judging means for judging whether a link operation that establishes the link for the traffic channel should be continued according to the measured electric field strength of the link establishment signal; and

a control means for terminating the link operation if a judgement result of the judging means is negative,

wherein the measuring means measures the electric field strength by calculating an average of electric field strengths measured in a plurality of slots, and each of the electric field strengths comprises first and second signal levels, the first signal level being determined by a reception signal received from the selected base station, and the second signal level being a noise level and determined by no reception signal received from the selected base station.

11. The base station of claim 10,

wherein the measured electric field strength includes a signal level and a noise level, the signal level being a reception signal level when a signal is received from the mobile station on the traffic channel, and the noise level being a reception signal level when no signal is received from the mobile station on the traffic channel, and

the judging means judges that the link operation should be terminated if the signal level is not more than a first threshold value or a difference between the signal level and the noise level is not more than a second threshold value.