TERMINAL, COMMUNICATION CIRCUIT AND COMMUNICATION METHOD

• US 20140071893A1
• Filed: 09/10/2013
• Published: 03/13/2014
• Est. Priority Date: 09/11/2012
• Status: Active Grant

• Current Assignee: Fujitsu Limited
• Original Assignee: Fujitsu Limited
• Inventors: KODAMA, Takeshi
• Granted Patent: US 9,345,051 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04W 56/00 Synchronisation arrangements
• CPC Class Codes: H04W 74/085 collision avoidance
• CPC Class Codes: H04W 74/0858 collision detection
• CPC Class Codes: H04W 76/18 Management of setup rejection or failure

Abstract

A terminal including: an antenna configured to transmit a first random access signal, when the terminal loses a synchronization with a base station, to the base station, and to transmit a second random access signal, when a response signal to the first random access signal is not received by the terminal, to the base station after a period, and a processor configured to obtain a detection result by detecting, when the terminal loses the synchronization with the base station, whether a communication is in progress or not, and to set the period based on the detection result.

Claims

1. A terminal comprising:

an antenna configured

to transmit a first random access signal, when the terminal loses a synchronization with a base station, to the base station, and

to transmit a second random access signal, when a response signal to the first random access signal is not received by the terminal, to the base station after a period; and

a processor configured

to obtain a detection result by detecting, when the terminal loses the synchronization with the base station, whether a communication is in progress or not, and

to set the period based on the detection result.

2. The terminal according to the claim 1, wherein the period is a first period when the detection result indicates the communication is in progress, the period is a second period when the detection result indicates the communication is not in progress, and the first period is shorter than the second period.

3. The terminal according to the claim 2, wherein the second period is set using a rule that the maximum period for the first period is shorter than the minimum period for the second period.

4. The terminal according to the claim 1, wherein the period is set in accordance with a specified timing of intermittent reception, when the detection result indicates that the communication is not in progress.

5. The terminal according to the claim 4, wherein the period is set to the specified timing after the maximum period for the first period.

6. The terminal according to the claim 1, wherein the period is a first period when the detection result indicates the communication is in progress, the period is the first period when the detection result indicates the communication is not in progress and data to be transmitted to the base station is detected, the period is a second period when the detection result indicates the communication is not in progress and data to be transmitted to the base station is not detected, and the first period is shorter than the second period.

7. The terminal according to the claim 1, wherein the period is varied based on a number of times when a response signal is transmitted from the base station in response to a random access signal transmitted by another terminal.

8. A communication circuit for the terminal, the communication circuit comprising:

a processor configured

to generate a first random access signal which is transmitted, when the terminal loses a synchronization with a base station, to the base station,

to generate a second random access signal which is transmitted, when a response signal to the first random access signal is not received by the terminal, to the base station after a period,

to obtain a detection result by detecting, when the terminal loses the synchronization with the base station, whether a communication is in progress or not, and

to set the period based on the detection result; and

a memory configured to couple to the processor.

9. A communication method comprising:

transmitting a first random access signal, when the terminal loses a synchronization with a base station, to the base station;

transmitting a second random access signal, when a response signal to the first random access signal is not received by the terminal, to the base station after a period;

obtaining a detection result by detecting, when the terminal loses the synchronization with the base station, whether a communication is in progress or not; and

setting the period based on the detection result.

10. The communication method according to the claim 9, wherein the period is a first period when the detection result indicates the communication is in progress, the period is a second period when the detection result indicates the communication is not in progress, and the first period is shorter than the second period.

11. The communication method according to the claim 10, wherein the second period is set using a rule that the maximum period for the first period is shorter than the minimum period for the second period.

12. The communication method according to the claim 9, wherein the period is set in accordance with a specified timing of intermittent reception, when the detection result indicates that the communication is not in progress.

13. The communication method according to the claim 12, wherein the period is set to the specified timing after the maximum period for the first period.

14. The communication method according to the claim 9, wherein the period is a first period when the detection result indicates the communication is in progress, the period is the first period when the detection result indicates the communication is not in progress and data to be transmitted to the base station is detected, the period is a second period when the detection result indicates the communication is not in progress and data to be transmitted to the base station is not detected, and the first period is shorter than the second period.

15. The communication method according to the claim 9, wherein the period is varied based on a number of times when a response signal is transmitted from the base station in response to a random access signal transmitted by another terminal.