COMMUNICATION SYSTEM

• US 20120163226A1
• Filed: 03/02/2012
• Published: 06/28/2012
• Est. Priority Date: 09/04/2009
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: TOMIZAWA, Takeshi, Tandai, Tomoya, Matsuo, Ryoko
• Granted Patent: US 8,724,499 B2
• Time in Patent Office: Days
• US Class Current: 370/252
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 1/1883 using multiple timers
• CPC Class Codes: H04W 36/06 Reselecting a communication resource in the serving access point

Abstract

According to one embodiment, a communication device includes a first wireless device configured to transmit a signal and a second wireless device configured to transmit a positive acknowledge when reception of the signal is successful. In the first wireless device, a first controller controls a first transmission module to change a first frequency channel based on a change order stored in a first storage when the positive acknowledge is not received even after the time measured by a first timer exceeds a first period. In the second wireless device, a second controller controls a second reception module to change the first frequency channel based on the change order stored in a second storage when the positive acknowledge is not transmitted even after the time measured by a second timer exceeds the first period.

Claims

1. A transmitter comprising:

a transmission module configured to transmit a signal to a communication partner;

a reception module configured to receive a positive acknowledge transmitted by the communication partner when the signal is successfully received by the communication partner;

a timer configured to measure a time elapsed from the reception of the positive acknowledge by the reception module;

a storage configured to store the order of change of a plurality of frequency channels to be used for transmission by the transmission module; and

a controller configured to control the transmission module to change the frequency channel based on the change order when the positive acknowledge is not received even after the time measured by the timer exceeds a first period.

2. The transmitter of claim 1, further comprising:

a third timer configured to measure a time elapsed from the transmission of the signal by the transmission module,

wherein the transmission module is configured to retransmit the signal when the positive acknowledge associated with the signal is not received for a certain period of time,

wherein when the positive acknowledge is not received even after the time measured by the third timer exceeds a second period, the controller is configured to control the transmission module to stop the retransmission of the signal, and

wherein the first period is longer than the certain period of time but is shorter than the second period.

3. The transmitter of claim 2,

wherein the transmission module is configured to transmit the signal received from a higher layer, and

wherein the timer is configured to stop time measurement when a next signal to be transmitted is not received from the higher layer even after a third period has elapsed from the transmission of the signal by the transmission module, and the timer is configured to restart the measurement from the time, at which the measurement has been stopped, when the transmission module has received, from the higher layer, the next signal to be transmitted.

4. The transmitter of claim 2,

wherein the first period (T1) is obtained by dividing the second period (T2) by a multiple of the number (n) of the plurality of frequency channels (i.e., T1=T2/kn where k denotes a natural number).

5. The transmitter of claim 1,

wherein when the transmission module transmits the signal by using a first frequency channel and then the positive acknowledge is not received even after the time measured by the timer exceeds the first period, the controller controls the transmission module to change the first frequency channel based on the change order.

6. A receiver comprising:

a reception module configured to receive a signal from a communication partner;

a transmission module configured to transmit a positive acknowledge to the communication partner when the reception of the signal is successful;

a timer configured to measure a time elapsed from the transmission of the positive acknowledge by the transmission module;

a storage configured to store the order of change of a plurality of frequency channels to be used for reception by the reception module; and

a controller configured to control the reception module to change the frequency channel based on the change order when the positive acknowledge is not transmitted even after the time measured by the timer exceeds a first period.

7. The receiver of claim 6,

wherein the timer is configured to stop time measurement when a next signal is not received even after a third period has elapsed from the reception of the signal by the reception module, and the timer is configured to restart the measurement from the time, at which the measurement has been stopped, when the reception module has received the next signal.

8. The receiver of claim 6,

wherein when the reception module receives the signal from the communication partner by using a first frequency channel and then the positive acknowledge is not transmitted even after the time measured by the timer exceeds the first period, the controller controls the reception module to change the first frequency channel based on the change order.