Systems and methods for broadband failover in land mobile radio networks

Patent metadata

Field	Value
Publication number	US-11540351-B2
Application number	US-202016796727-A
Country	US
Kind code	B2
Filing date	Feb 20, 2020
Priority date	Feb 20, 2020
Publication date	Dec 27, 2022
Grant date	Dec 27, 2022

Abstract

Systems and methods for broadband failover in land mobile radio networks. One method includes operating a first communication interface of a converged communication device to execute a first communication between the device and a first network using an LMR modality. The method includes determining a plurality of radio communication characteristic values for each of a plurality of sites of the first network and generating a fallback threshold for a home site of the device based on the plurality of radio communications characteristics. The method includes determining whether a current radio communication characteristic value associated with a home site of the device exceeds the fallback threshold, and, when the current radio communication characteristic value does not exceed the fallback threshold, operating a second communication interface of the converged communication device to execute a second communication between the device and a second network using a non-LMR modality.

First claim

We claim:

1. A converged communication device comprising:
a first communication interface configured to communicate with a land mobile radio (LMR) network using a first communication modality, the first communication modality being a land mobile radio (LMR) modality;
a second communication interface configured to communicate with a broadband network using a second communication modality, the second communication modality being a non-land mobile radio broadband modality; and
an electronic processor coupled to the memory, the first communication interface, and the second communication interface, and configured to
operate the converged communication device using the first communication modality to execute a first communication between the converged communication device and the land mobile radio (LMR) network,
determine a plurality of radio communication characteristic values for each of a plurality of sites of the land mobile radio (LMR) network,
generate a fallback threshold for a home site of the converged communication device based on the plurality of radio communications characteristics;
for each of the plurality of sites, generate a return threshold based on the plurality of radio communications characteristics;
determine whether a current radio communication characteristic value associated with a home site of the converged communication device exceeds the fallback threshold,
when the current radio communication characteristic value does not exceed the fallback threshold, operate the converged communication device using the second communication modality to execute a second communication between the converged communication device and the broadband network;

while operating the converged communication device using the second communication modality,
control the first communication interface to scan the plurality of sites to determine a second plurality of radio communication characteristic values;
for each of the plurality of sites, determine, based on the second plurality of radio communication characteristic values, a service quality rating;
select, from the plurality of sites, a potential return site based on the service quality rating; and
when the received signal strength intensity for the potential return site exceeds the return threshold for the potential return site, operate the converged communication device using the first communication modality.

2. The converged communication device of claim 1 , wherein the electronic processor is configured to operate the converged communication device using the first communication modality when the received signal strength intensity for the potential return site exceeds the return threshold and a minimum stay timer has expired.

3. The converged communication device of claim 1 , wherein the electronic processor is configured to generate a return threshold based on the fallback threshold and a received signal strength intensity hysteresis buffer.

4. The converged communication device of claim 1 , further comprising:
a memory;
wherein the electronic processor coupled to the memory and configured to
detect a service failure for the home site based on at least one radio communication characteristic value for the home site; and
write, to the memory, the at least one radio communication characteristic value for the home site at the time of the service failure and a received signal strength intensity level for the home site at the time of the service failure.

5. The converged communication device of claim 4 , wherein the electronic processor is configured to
in response to detecting the service failure, determine whether a failure tolerance threshold has been exceeded; and
when the failure tolerance threshold has been exceeded, operate the converged communication device using the second communication modality to execute a second communication between the converged communication device and the broadband network.

6. The converged communication device of claim 4 , wherein the electronic processor is configured to detect a service failure for the home site based on at least one selected from the group consisting of an out of range error, a retry failure, and a bit error rate.

7. The converged communication device of claim 4 , wherein the electronic processor is configured to
retrieve from the memory the at least one radio communication characteristic value for the home site at the time of the service failure; and
determine the fallback threshold based on the plurality of radio communications characteristics, the at least one radio communication characteristic value for the home site at the time of the service failure, and the received signal strength intensity level for the home site at the time of the service failure.

8. The converged communication device of claim 1 , wherein the first communication is a push-to-talk communication.

9. The converged communication device of claim 1 , wherein the electronic processor is configured to determine a plurality of radio communication characteristic values by determining at least one of a control channel frequency, a site identifier, a system accessibility, and an acceptable received signal strength intensity level.

10. A method for operating a converged communication device, the method comprising:
operating a first communication interface of the converged communication device to execute a first communication between the converged communication device and a land mobile radio (LMR) network using a land mobile radio (LMR) modality;
determining, with an electronic processor, a plurality of radio communication characteristic values for each of a plurality of sites of the land mobile radio (LMR) network;
generating a fallback threshold for a home site of the converged communication device based on the plurality of radio communications characteristics;
generating, for each of the plurality of sites, a return threshold based on the plurality of radio communications characteristics;
determining whether a current radio communication characteristic value associated with a home site of the converged communication device exceeds the fallback threshold;
when the current radio communication characteristic value does not exceed the fallback threshold, operating a second communication interface of the converged communication device to execute a second communication between the converged communication device and a second broadband network using a non-land mobile radio broadband modality;
while operating the converged communication device using the non-land mobile radio broadband modality,
controlling, with the electronic processor, the first communication interface to scan the plurality of sites to determine a second plurality of radio communication characteristic values;
for each of the plurality of sites, determining, based on the second plurality of radio communication characteristic values, a service quality rating;
selecting, from the plurality of sites, a potential return site based on the service quality rating; and

when the received signal strength intensity for the potential return site exceeds the return threshold for the potential return site, operating the converged communication device using the land mobile radio (LMR) modality.

11. The method of claim 10 , further comprising:
operating the converged communication device using the land mobile radio (LMR) modality when the received signal strength intensity for the potential return site exceeds the return threshold and a minimum stay timer has expired.

12. The method of claim 10 , wherein generating a return threshold includes generating a return threshold based on the fallback threshold and a received signal stre

Assignees

• Motorola Solutions Inc

Inventors

• Chen Dajun
• Almasi Andor
• Mills David R

Classifications

• H04W48/18

  Selecting a network or a communication service · CPC title

• H04W36/0079

  in case of hand-off failure or rejection · CPC title

• H04W88/06 Primary

  adapted for operation in multiple networks {or having at least two operational modes}, e.g. multi-mode terminals · CPC title

• H04W8/26

  Network addressing or numbering for mobility support · CPC title

• H04W88/02

  Terminal devices · CPC title