METHOD TO SCAN FOR CRITICAL TRANSMISSIONS WHILE TRANSMITTING ON A CONVENTIONAL TIME DIVISION MULTIPLE ACCESS CHANNEL

• US 20090219916A1
• Filed: 02/29/2008
• Published: 09/03/2009
• Est. Priority Date: 02/29/2008
• Status: Abandoned Application

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: BOHN, THOMAS
• Application Number:
  US12/040,442
• Publication Number:
  US 20090219916A1
• Time in Patent Office: Days
• US Class Current: 370/347
• CPC Class Codes: H04W 74/0816 with collision avoidance

Abstract

A method allowing wireless communications devices to scan for critical transmissions while transmitting on a conventional time division multiple access channel (TDMA) is disclosed. The TDMA channel is divided into a plurality of slots, each slot capable of carrying audio, video, control, and/or data transmissions. A first slot is used by a first communication device, while a second slot is used by a second communication device. The first communication device transmits at least one burst of information from a first transmission in a first slot. The first communication device switches to a second slot and reads at least one signaling information segment embedded in a second transmission that is being transmitted in the second slot. The first communication device determines to terminate the first transmission in order to receive the second transmission, or to switch back to the first slot and repeat the steps of transmitting, switching, reading and determining.

Claims

1. A method for scanning for critical transmissions while transmitting on a convention time division multiple access (TDMA) channel in a wireless communication system, the TDMA channel having a plurality of slots, the method comprising the steps of, at a communication device:

transmitting at least one burst of information from a first transmission in a first slot;

switching to a second slot;

reading at least one signaling information segment embedded in a second transmission that is being transmitted in the second slot; and

determining whether to terminate the first transmission in order to receive the second transmission, or to switch back to the first slot and repeat the steps of transmitting, switching, reading and determining.

2. The method in accordance with claim 1, wherein the communication device performs the step of determining without receiving instructions from another device in the wireless communication system.

3. The method in accordance with claim 1, further comprising the step of determining that the signaling information segments embedded in the second transmission that are needed to assemble a link control message have been read prior to determining to terminate the first transmission in order to receive the second transmission.

4. The method in accordance with claim 3, further comprising the step of determining whether the second transmission is a critical transmission based on the link control message, and wherein the step of determining to switch back to the first slot and repeat the steps of transmitting, switching, reading and determining occurs if the second transmission is determined not to be a critical transmission.

5. The method in accordance with claim 4, wherein the step of determining whether the second transmission is a critical transmission comprises at least one of the following:

scanning a service options field in the link control message;

scanning an emergency bit in the link control message;

or

scanning a priority bit in the link control message.

6. The method in accordance with claim 3, further comprising the step of determining whether the second transmission is a critical transmission based on the link control message, and wherein the step of determining to terminate the first transmission in order to receive the second transmission occurs if the second transmission is a critical transmission.

7. The method in accordance with claim 6, wherein the step of determining whether the second transmission is a critical transmission comprises at least one of the following:

scanning a service options field in the link control message;

scanning an emergency bit in the link control message;

or

scanning a priority bit in the link control message.

8. The method in accordance with claim 1, further comprising the step of determining whether the second transmission is a critical transmission by comparing a priority value of the second transmission with a priority value of the first transmission, and wherein the step of determining to terminate the first transmission in order to receive the second transmission, or to switch back to the first slot and repeat the steps of transmitting, switching, reading and determining is based on whether the second transmission is determined to be a critical transmission.

9. The method in accordance with claim 1, wherein the first transmission and the second transmission comprise at least one of:

audio information, video information, control information, or data information.

10. The method in accordance with claim 1, wherein the steps of switching to the second slot, and reading at least one signaling information segment embedded in the second transmission that is being transmitted in the second slot do not interfere with transmitting the first transmission in the first slot.

11. The method in accordance with claim 1, wherein the step of determining to switch back to the first slot and repeat the steps of transmitting, switching, reading and determining occurs if the signaling information segments embedded in the second transmission that is needed to assemble a link control message has not been read.

12. The method in accordance with claim 1, wherein the communication device operates in a half-duplex mode.

13. A method for scanning for critical transmissions while transmitting on a convention time division multiple access (TDMA) channel in a wireless communication system, the TDMA channel having a plurality of slots, the method comprising the steps of, at a communication device:

transmitting at least one burst of information from a first transmission in a first slot;

switching to a second slot;

reading at least one signaling information segment embedded in a second transmission that is being transmitted in the second slot;

switching back to the first slot and repeating the steps of transmitting, switching, reading, and switching back until the signaling information segments embedded in the second transmission that is needed to assemble a link control message has been read; and

upon reading the signaling information segments embedded in the second transmission that is needed to assemble the link control message, determining whether to terminate transmission of the first transmission in order to receive the second transmission, or switch back to the first slot and repeat the steps of transmitting, switching, reading, and switching back.

14. The method in accordance with claim 13, wherein the communication device performs the step of determining without receiving instructions from a device in the wireless communication system.

15. The method in accordance with claim 13, further comprising the step of determining whether the second transmission is a critical transmission by comparing a priority value of the second transmission with a priority value of the first transmission, and wherein the step of determining to terminate the first transmission in order to receive the second transmission, or to switch back to the first slot and repeat the steps of transmitting, switching, reading and switching back is based on whether the second transmission is determined to be a critical transmission.

16. A communication device used for scanning for critical transmissions while transmitting on a convention time division multiple access (TDMA) channel in a wireless communication system, the TDMA channel having a plurality of slots, the communication device comprising at least a processor, and a transmitter coupled to the processor, wherein the processor selectively performs the following functions:

instructing the transmitter to transmit at least one burst of information from a first transmission in a first slot;

switching to a second slot;

reading at least one signaling information segment embedded in a second transmission that is being transmitted in the second slot; and

determining whether to terminate the first transmission in order to receive the second transmission, or to switch back to the first slot and repeat the steps of instructing, switching, reading and determining.

17. The communication device in accordance with claim 16, wherein the processor selectively performs the step of determining without receiving instructions from another device in the wireless communication system.

18. The communication device in accordance with claim 16, wherein the processor selectively performs the further step of determining that the signaling information segments embedded in the second transmission that are needed to assemble a link control message have been read prior to determining to terminate the first transmission in order to receive the second transmission.

19. The communication device in accordance with claim 16, wherein the processor selectively performs the further step of determining whether the second transmission is a critical transmission by comparing a priority value of the second transmission with a priority value of the first transmission, and wherein the step of determining to terminate the first transmission in order to receive the second transmission, or to switch back to the first slot and repeat the steps of transmitting, switching, reading and determining is based on whether the second transmission is determined to be a critical transmission.

20. The communication device in accordance with claim 16, wherein the first transmission and the second transmission comprise at least one of:

audio information, video information, control information, or data information.