System and method for interrupting a transmitting device in a communication system

• US 8,605,650 B2
• Filed: 06/10/2008
• Issued: 12/10/2013
• Est. Priority Date: 06/10/2008
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Wiatrowski, David G., Bohn, Thomas B., Chowdhary, Dipendra M.
• Primary Examiner(s): LI, GUANG W
• Application Number:
  US12/136,177
• Publication Number:
  US 20090303923A1
• Time in Patent Office: 2,009 Days
• Field of Search: 370/328
• 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 transmitting a call from a first device to one or more other devices via a base station in a communication system, the method comprising:

a first device encoding call information of a call to be transmitted into a series of channel frames;

the first device operating in a transmitting mode and transmitting the call on a first communication channel between the first device and the base station via the series of channel frames, and the first device inserting a plurality of open channel frame periods on to the first communication channel during transmission of the call by selectively dropping, instead of transmitting, a corresponding predetermined plurality of the channel frames or portions of the channel frames;

the first device switching to a receiving mode during one of the inserted open channel frame periods and determining, while in the receiving mode, whether an interrupt request has been transmitted from a second device to the repeater and has subsequently been repeated on a second communication channel by the base station and received at the first device; and

responsive to the first device determining that an interrupt request has been transmitted from the second device and has been received at the first device via the base station, as a function of the interrupt request, at least one of;

the first device ceasing transmitting of the call on the first communication channel; and

the first device pausing transmission of the call on the first communication channel for a predetermined period of time.

2. The method of claim 1, wherein:

the call is transmitted as a series of superframes, each superframe having one or more channel frames,

the plurality of open channel frame periods are provided periodically during transmission of the call, and

an open channel frame period is provided once every x superframes transmitted during the call, wherein x is an integer greater than or equal to one.

3. The method of claim 2, 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 frames from the series of information frames; and

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

4. The method of claim 3, wherein one information frame is discarded after transmission of each superframe.

5. The method of claim 1, further including the first device transmitting an acknowledgment message acknowledging receipt of the interrupt request to the base station after receiving the interrupt request.

6. 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; and

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

7. The method of claim 1, wherein the first device is a radio and the second device is one of a console site and another radio.

8. The method of claim 1, further comprising the first device embedding an indication in a channel frame, prior to each open channel frame period, of when the next open channel frame period will occur.

9. The system of claim 1, wherein the base station is further configured to receive an acknowledgment of a receipt of the repeated interrupt request from the first device, and responsively transmit a further acknowledgment to the second device.

10. The method of claim 1, wherein the at least one of the dropped channel frames or portions of the channel frames includes call audio data.

11. The method of claim 1, wherein the at least one of the dropped channel frames or portions of the channel frames includes call control information.

20. The system of claim 1, wherein the first device is a radio and the second device is one of a console site and another radio.

12. A method for interrupting a transmitting device transmitting a call from a second device to one or more other devices, including a first device, via a base station in a communication system, the method comprising:

the first device operating in a receiving mode and receiving a first call on a first communication channel between the first device and the base station via a series of channel frames, and the first device receiving erasure bursts inserted by the base station on the first communication channel during corresponding open channel frame periods inserted on to a second communication channel between the base station and the second device during transmission of the call by the second device selectively dropping, instead of transmitting, a corresponding predetermined plurality of the channel frames or portions of the channel frames, the erasure bursts indicating to the first device that no call information was received at the base station from the second device;

the first device mitigating the dropped corresponding predetermined plurality of the channel frames or portions of the channel frames caused by the second device'"'"'s insertion of the open channel frame periods;

the first device determining that the first call being transmitted by the second device should be interrupted;

the first device switching from operating in the receive mode to operating in a transmit mode during one of the open channel frame periods;

the first device, while in the transmit mode and during the one of the open channel frame periods, transmitting an interrupt request to the base station on the second communication channel for forwarding to the second device via the base station during a subsequent open channel frame period, the interrupt request instructing the second device to one of cease transmitting of the call on the second communication channel and pause transmitting of the call on the second communication channel for a predetermined period of time; and

after transmitting the interrupt request, the first device transmitting a second call on the second communication channel.

13. The method of claim 12, further including the first device determining whether an acknowledgment of the interrupt request has been received from the second device via the base station, and the first device transitioning from the receiving mode to the transmitting mode and transmitting the second call responsive to receiving the acknowledgement.

14. The method of claim 12, wherein the first device is a radio and the first device waits to receive an acknowledgment from the base station that the base station has successfully interrupted the second device before transmitting the second call on the second communication channel.

15. The method of claim 12, further comprising determining a next open channel frame period from information embedded in one or more received channel frames of the call;

wherein the step of switching the first device from operating in the receive mode to operating in the transmit mode is executed during the determined next open channel frame period.

16. The method of claim 12, wherein the second device is a radio and the first device is one of a console site and another radio.

17. A system for interrupting a transmitting device transmitting a call from a first device to one or more other devices via a base station in a communication system comprising:

a first device configured to;

encode call information of a call to be transmitted into a series of channel frames;

operate in a transmit mode and transmit a first call on a first communication channel between the first device and the base station via the series of channel frames;

insert a plurality of open channel frame periods on to the first communication channel during transmission of the first call by selectively dropping, instead of transmitting, a corresponding predetermined plurality of the channel frames or portions of the channel frames;

switch to a receive mode during at least one of the inserted plurality of open channel frame periods; and

receive a call interrupt request on a second communication channel, originally transmitted from a second device and repeated by the base station on the second communication channel, and, as a function of the interrupt request, cease transmitting the call or pause transmitting the call for a predetermined amount of time;

a second device configured to;

operate in a receive mode and receive the first call on the second communication channel between the second device and the base station, including receiving erasure bursts on the second communication channel during repeating transmission of the open channel frame periods to indicate to the second device by the base station that no call information was received at the base station from the first device;

mitigate the dropped corresponding predetermined plurality of the channel frames or portions of the channel frames caused by the first device'"'"'s insertion of the open channel frame periods;

determine that the first call being transmitted by the first device should be interrupted and responsively switch from the receive mode to a transmit mode during one of the open channel frame periods inserted by the first device and transmit the call interrupt request to the base station on the first communication channel for forwarding to the first device via the base station during a subsequent open channel frame period, the interrupt request instructing the first device to cease transmitting of the call on the first communication channel; and

after transmitting the call interrupt request, transmit a second call on the first communication channel.

18. The system of claim 17, wherein the first device is further configured to embed an indication in a channel frame, prior to each open channel frame period, of when the next open channel frame period will occur.

19. The system of claim 17, wherein the at least one of the dropped channel frames or portions of the channel frames includes call audio data, and wherein the second device is configured to mitigate the dropped call audio data.