Method and apparatus for automatically determining a communication range status of communicating radios

• US 9,232,382 B2
• Filed: 05/31/2012
• Issued: 01/05/2016
• Est. Priority Date: 05/31/2012
• Status: Active Grant

• Current Assignee: Motorola Solutions, Inc.
• Original Assignee: Motorola Solutions, Inc.
• Inventors: Wiatrowski, David G., Chung, Yueh Ching, Teh, Teik Choon
• Primary Examiner(s): Wang, Fanghwa
• Application Number:
  US13/485,148
• Publication Number:
  US 20130324177A1
• Time in Patent Office: 1,314 Days
• US Class Current: 1/1
• CPC Class Codes: H04W 8/005 Discovery of network devices, e.g. terminals

Abstract

A method is disclosed for determining a connectivity status of radios in a coverage group. Each coverage group includes radios configured to transmit and receive range messages on a channel and a timeslot. Each radio in the coverage group is configured to generate a range message and to transmit the range message to each other radio in the coverage group. Each radio in the coverage group is also configured to receive, from each other radio in the coverage group, a range message generated by each other radio. Based on the range message received from each other radio, each radio is configured to determine bi-directional connectivity between the receiving radio and the radios that sent the D-ARTS messages. The determined bi-directional connectivity status is between each radio and each of at least two other radios in the coverage group.

Claims

1. A method for determining a connectivity status of radios in a coverage group, wherein each coverage group includes radios configured to transmit and receive range messages on a channel and a timeslot, the method comprising:

generating, by a radio in the coverage group, a generated range message comprising;

a connection field for connecting multiple range messages; and

a synchronization bit for facilitating startup of an exclusive transmission window sequence, wherein when the communicating radio knows that the generated range message is being transmitted in a proper window, the synchronization bit is set to a predefined value;

transmitting, by the radio, the generated range message to each other radio in the coverage group;

receiving, by the radio from each other radio in the coverage group, a received range message generated by each other radio, wherein the received range message from each other radio includes a bitmask field indicating whether the radio received a generated range message during a previous polling interval, thereby indicating the presence or absence of the each other radio in the coverage group; and

based on the received range message received from each other radio, determining, by the radio, bi-directional connectivity status between the radio and each other radio in the coverage group, wherein the determined bi-directional connectivity status is between the radio and each of at least two other radios in the coverage group.

2. The method of claim 1, wherein the transmitting comprises computing a source identifier for each radio in each coverage group configured to operate on the channel and the timeslot using a fundamental group size assigned to at least one coverage group,

wherein the source identifier is based on an indexed position of each radio in a coverage group list.

3. The method of claim 2, wherein each generated range message is transmitted during an exclusive transmission window assigned to each radio in the coverage group, wherein the exclusive transmission window assigned to each radio is determined based on a coverage group identifier and the source identifier.

4. The method of claim 1, further comprising identifying a mode for operating on the channel and the timeslot based on a predefined set of bits in the received range message.

5. The method of claim 4, wherein the mode in the predefined set of bits indicates how many bits of the received range message are used to identify a coverage group number and how many bits of the range message are used to identify a particular radio in the coverage group.

6. The method of claim 1, wherein the generated range message includes a source field for identifying the radio that generated the generated range message.

7. The method of claim 1, wherein the receiving comprises receiving a single received range message per polling interval from each other radio in the coverage group.

8. The method of claim 1, wherein each radio in the coverage group is provisioned with a coverage group list for identifying radios in the coverage group, wherein identified radios in the coverage group are those radios on a channel whose communications status each radio in the coverage group tracks.

9. The method of claim 1, further comprising providing, by the radio, an alert when another radio in the coverage group is determined by the radio to be out of communication range with the radio according to the bi-directional connectivity status between the radio and the other radio.

10. The method of claim 1, further comprising transmitting the generated range message from each radio in the coverage group to a repeater in response to a poll initiated by the repeater.

11. A communicating radio configured to determine a connectivity status of radios in a coverage group, the communicating radio comprises:

a storing unit configured to store a coverage group list that identifies each other radio in the coverage group; and

a transmission unit configured to transmit, to each other radio in the coverage group, a generated range message generated by the communicating radio, the generated range message comprising;

a connection field for connecting multiple range messages; and

a synchronization bit for facilitating startup of an exclusive transmission window sequence, wherein when the communicating radio knows that the generated range message is being transmitted in a proper window, the synchronization bit is set to a predefined value;

a receiving unit configured to receive, from each other radio in the coverage group, a received range message generated by each other radio, wherein the received range message includes a bitmask field for indicating whether the receiving unit received a generated range message from the each other radio during a previous polling interval, thereby indicating a presence or absence status of the each other radio in the coverage group; and

a determining unit configured to determine, based on the received range message received from each other radio, bi-directional connectivity status between the communicating radio and each other radio in the coverage group, wherein the determined bi-directional connectivity status is between the communicating radio and each of at least two other radios in the coverage group.

12. The communicating radio of claim 11, wherein during transmission of the generated range message, the communicating radio is configured to use a fundamental group size assigned to at least one coverage group that operates on a channel and a timeslot, and a source identifier computed for each radio in each coverage group based on an indexed position of each radio in a coverage group list.

13. The communicating radio of claim 12, wherein the generated range message transmitted during the exclusive transmission window is assigned to each radio in the coverage group, wherein the exclusive transmission window assigned to each radio is determined based on a coverage group identifier and the source identifier.

14. The communicating radio of claim 11, further configured to identify a mode for operating on a channel and a timeslot based on a predefined set of bits in the received range message, wherein the mode in the predefined set of bits indicates how many bits of the received range message are used to identify a coverage group number and how many bits of the range message are used to identify a particular radio in the coverage group.

15. The communicating radio of claim 11, wherein the generated range message generated by the communicating radio comprises:

a source field for identifying the communicating radio.

16. The communicating radio of claim 11, wherein the transmitting unit is configured to transmit a single generated range message per polling interval.

17. The communicating radio of claim 11, wherein the transmitting unit is configured to transmit the generated range message to a repeater in response to a poll initiated by the repeater.