# How is lost GPS signal reception handled by ePMP Synchronized radios?

**URL:** https://community.cambiumnetworks.com/t/how-is-lost-gps-signal-reception-handled-by-epmp-synchronized-radios/40374
**Category:** ePMP
**Tags:** knowledge-base
**Created:** [April 28, 2015, 12:28pm UTC](https://community.cambiumnetworks.com/t/how-is-lost-gps-signal-reception-handled-by-epmp-synchronized-radios/40374 "2015-04-28T12:28:06Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Cambium\_Marty](https://d10gw3vjmzyp8.cloudfront.net/user_avatar/community.cambiumnetworks.com/cambium_marty/32/11547_2.png) [@Cambium\_Marty](https://community.cambiumnetworks.com/u/Cambium_Marty)
#### Post date: [April 28, 2015, 12:28pm UTC](https://community.cambiumnetworks.com/t/how-is-lost-gps-signal-reception-handled-by-epmp-synchronized-radios/40374/1 "2015-04-28T12:28:06Z")

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Receiving a reliable GPS signal is important to the operation of synchronized ePMP systems. &nbsp;In the case where GPS signaling is unreliable, ePMP software includes a Synchronization Holdoff feature which allows SM registrations to persist while the AP attempts to regain sync pluses. &nbsp;

The&nbsp; **Synchronization Holdoff Time&nbsp;** is designed to gracefully handle fluctuations/losses in the GPS synchronization signaling. After the AP has received a reliable synchronization pulse for at least 60 seconds, if there is a loss of synchronization signal, the&nbsp; **Synchronization Holdoff&nbsp;** timer is started. During the holdoff interval, all SM registrations are maintained. If a valid GPS synchronization pulse is regained during the holdoff interval, then the AP continues to operate normally. If a valid synchronization pulse is not regained from the GPS source during the holdoff interval, then the AP ceases radio transmission. Default is&nbsp; **30 seconds. &nbsp;**

Adjusting this parameter to a shorter time period&nbsp;of time gives&nbsp;operators tighter control on unsynchronized network operation (when GPS signaling is not present). &nbsp;Adjusting this parameter to a longer time period affords time for the AP to regain a GPS satellite fix in more challenging GPS signaling environments/installations but allows more free-running network operation which may introduce interference for other ePMP deployments within range.

Default time duration is 30 seconds

Max duration is 86400 = 24 hours

![holdoff.jpg](https://d1okf4ta8xniw3.cloudfront.net/original/2X/f/fdac5733aed8f0eb8d9b82becb9108a6bead8cb8.jpeg "holdoff.jpg")