SYSTEM AND METHOD FOR INTERRUPTING A TRANSMITTING DEVICE IN A COMMUNICATION SYSTEM

• US 20090303923A1
• Filed: 06/10/2008
• Published: 12/10/2009
• Est. Priority Date: 06/10/2008
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Bohn, Thomas B., Wiatrowski, David G., Chowdhary, Dipendra M.
• Granted Patent: US 8,605,650 B2
• Time in Patent Office: Days
• US Class Current: 370/328
• CPC Class Codes: H04L 47/245 using preemption
• CPC Class Codes: H04L 47/32 by discarding or delaying data units, e.g. packets or frames
• CPC Class Codes: H04M 3/20 with means for interrupting existing connections; with means for breaking-in on conversations
• CPC Class Codes: H04W 4/06 Selective distribution of broadcast services, e.g. multimedia broadcast multicast service [MBMS]; Services to user groups; One-way selective calling services
• CPC Class Codes: H04W 76/28 Discontinuous transmission [DTX]; Discontinuous reception [DRX]
• CPC Class Codes: H04W 76/36 for reassigning the resources associated with the released connections

Abstract

A system and method for interrupting a transmitting device during a call. In the system, calls are transmitted from a first device on a communication channel as a series of channel frames. At predetermined times during the transmission, the transmitting device is configured to drop channel frames, resulting in open channel frame periods where the transmitting device is not transmitting on the communication channel. During these open channel frame periods, the transmitting device is also configured to switch to a receiving mode. Other devices in the system are capable of switching into a transmitting mode during the open channel frame periods and, when applicable, sending an interrupt request on the communication channel to the transmitting device in order to request access to the channel.

Claims

1. A method for interrupting a transmitting device in a communication system, the method, at a first device, comprising:

operating the first device in a transmitting mode to transmit a call on a communication channel, wherein the call is transmitted as a series of channel frames, and wherein a plurality of open channel frame periods are provided on the communication channel during transmission of the call;

switching the first device to a receiving mode during at least one of the open channel frame periods;

determining, while in the receiving mode, whether an interrupt request has been transmitted from a second device; and

if an interrupt request has been transmitted from the second device, performing an appropriate action based on the interrupt request.

2. The method of claim 1 wherein each of the first device and the second device is a radio, and wherein the interrupt request is received by the first device directly from the second device or from the second device via a base station.

3. The method of claim 1 wherein the first device is a radio and the second device is a base station.

4. The method of claim 3 wherein, the interrupt request is transmitted from the base station in response to receiving a command from a console site to interrupt the first device.

5. The method of claim 1 wherein performing an appropriate action comprises one of the following:

ceasing transmitting of the call being transmitted from the first device;

pausing transmission of the call being transmitted from the first device;

or

providing a user-perceivable signal to a user.

6. The method of claim 1 wherein the call is transmitted as a series of superframes, each superframe having one or more channel frames.

7. The method of claim 6 wherein the plurality of open channel frame periods are provided periodically during transmission of the call.

8. The method of claim 7 wherein an open channel frame period is provided once every x superframes transmitted during the call, wherein x is an integer.

9. The method of claim 8 wherein each of the series of channel frames is comprised of a predetermined number of information frames and wherein the method further includes, in the transmitting mode:

encoding a series of information frames;

generating the series of channel from the series of information frames; and

periodically discarding an information frame while generating the series of channel frames.

10. The method of claim 9 wherein one information frame is discarded after transmission of each superframe.

11. The method of claim 1 further including transmitting an acknowledgment message to the second device after receiving the interrupt request.

12. The method of claim 1 wherein the communication system is one of the following:

a time division multiple access (TDMA) system and the call is transmitted as a series of bursts;

or

a frequency division multiple access (FDMA) system and the call is transmitted as a series of payload frames.

13. A method for interrupting a transmitting device in a communication system, the method, at a first device, comprising:

operating the first device in a receiving mode to receive a first call on a communication channel, wherein the first call is being transmitted from a second device as a series of channel frames, and wherein a plurality of open channel frame periods are provided on the communication channel during transmission of the call;

determining that the second device should be interrupted;

switching the first device to a transmitting mode during at least one of the open channel frame periods; and

in the transmitting mode, transmitting an interrupt request to the second device.

14. The method of claim 13 further including, after transmitting the interrupt, transmitting a second call from the first device on the communication channel.

15. The method of claim 14 further including determining whether an acknowledgment of the interrupt request has been received from the second device, and transmitting the second call upon determining that the acknowledgement has been received.

16. The method of claim 13 wherein the first device is configured to determine whether the second call includes a plurality of open channel frame periods, and switch to the transmitting mode only upon determining that the second call includes a plurality of open channel frame periods.

17. The method of claim 13 further including providing mitigated call information to a user during at least one of the plurality of open channel frame periods.

18. A system for interrupting a transmitting device in a communication system comprising:

a first device configured to operating in a transmitting mode to transmit a first call on a communication channel as a series of channel frames, wherein a plurality of open channel frame periods are provided on the communication channel during transmission of the first call, and wherein the first device is further configured to switch to a receiving mode during at least one of the plurality of open channel frame periods;

a second device configured to receive the first call on the communication channel, switch to a transmitting mode to transmit an interrupt request to the first device during at least one of the plurality of open channel frame periods if it is determined that the first device should be interrupted.

19. The system of claim 18 wherein the second device is further configured to transmit a second call on the communication channel after transmitting the interrupt request.

20. The system of claim 18 wherein the first call is being transmitted directly from the first device to the second device or from the first device to the second device via a base station.

21. The system of claim 20 wherein the base station is configured to determine whether the second device has transmitted the interrupt request, and broadcast the interrupt request to the first device during an open burst period.

22. The system of claim 21 wherein the first call is transmitted as a series of superframes, each superframe having one or more channel frames, and wherein the base station is further configured to broadcast the interrupt requests during each channel frame period in a superframe containing an open channel frame period.