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

• US 9,178,987 B2
• Filed: 08/30/2013
• Issued: 11/03/2015
• Est. Priority Date: 06/10/2008
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Chowdhary, Dipendra M, Wiatrowski, David G, Bohn, Thomas B
• Primary Examiner(s): LI, GUANG W
• Application Number:
  US14/014,758
• Publication Number:
  US 20140016514A1
• Time in Patent Office: 795 Days
• US Class Current: 1/1
• 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 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 communication channel via the series of channel frames, and the first device inserting a plurality of open channel frame periods on to the 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 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 received at the first device, as a function of the interrupt request, at least one of;

the first device ceasing transmitting of the call; and

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

2. The method of claim 1, wherein the first device is a radio and:

the second device is a radio, and 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 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.

4. The method of claim 3, 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.

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

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

7. 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.

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

10. 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.

15. The method of claim 1, wherein the call is transmitted directly from the first device to the second device.

11. A method for interrupting a transmitting device in a communication system, the method comprising:

a first device operating in a receiving mode and receiving a first call on a communication channel via a series of channel frames, and wherein a plurality of open channel frame periods are inserted on to the communication channel during transmission of the call by a second device selectively dropping, instead of transmitting, a corresponding predetermined plurality of the channel frames or portions of the channel frames;

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 must 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 inserted by the second device;

the first device, while in the transmit mode and during the one of the open channel frame periods, transmitting an interrupt request to the second device; and

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

12. The method of claim 11, further including the first device determining whether an acknowledgment of the interrupt request has been received from the second device, and the first device transmitting the second call responsive to receiving the acknowledgement.

13. The method of claim 11, 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 the receive mode to a transmit mode is executed during the determined next open channel frame period.

14. A system for interrupting a transmitting device transmitting a call 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 communication channel via the series of channel frames;

insert a plurality of open channel frame periods on to the 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 from a second device 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;

receive the first call on the communication channel;

mitigate 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;

determine that the first call being transmitted by the first device must be interrupted and responsively switch to a transmitting mode during one of the open channel frame periods inserted by the second device and transmit the call interrupt request to the first; and

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

16. The system of claim 14, 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.

17. The system of claim 14, 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.