Methods and systems for presenting an alert when leaving a direct-mode coverage area
US9961179B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 2014 |
| Grant date | May 1, 2018 |
| Priority date | — |
| Expiry date | Jul 28, 2034 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04W84/18
- WIPO fieldDigital communication
- WIPO sectorElectrical engineering
Abstract
At least one embodiment takes the form of a process carried out by a given mobile radio in a group of mobile radios. The process includes broadcasting heartbeat messages in accordance with a group-wide symmetric-timing protocol and maintaining an in-range list of mobile radios. The in-range list is maintained at least in part by (i) adding mobile radios that are not already on the in-range list to the in-range list upon detecting transmissions from such mobile radios; (ii) maintaining, for each mobile radio on the in-range list, a respective keepalive timer in accordance with the group-wide symmetric-timing protocol; and (iii) removing mobile radios from the in-range list upon expiration of the respective keepalive timers. The process further includes presenting an alert via a user interface when a count of mobile radios on the in-range list falls below a notification threshold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.