Soracom Air for Cellular

eDRX and PSM Timer Configuration

Extended Discontinuous Reception (eDRX) and Power Saving Mode (PSM) timers are cellular network parameters that control the intervals at which a device wakes up to receive signals from the network. With LTE Cat-M1 (LTE-M) and NB-IoT networks, these parameters can be increased in order to reduce the wake-up frequency and potentially improve battery life.

Normally, these eDRX and PSM parameters should be configured directly on your device. The parameters will be sent from the device to the local network as part of the network attach process.

However, Soracom provides a feature that allows you to set the eDRX and PSM timer parameters within a group. When a Soracom IoT SIM belonging to the group attaches to a network, the eDRX and PSM timer parameters will be sent from Soracom to the local network, allowing these parameters to be configured and managed on the network-side without the need to modify device firmware or configuration directly.

This feature is currently available as a limited preview. If you are interested in using this feature, please contact us in order to request access.

Please note that in some cases, a local network may override eDRX and PSM timers, regardless of whether the parameters are sent by the device or by Soracom.

Reference Information

DRX is a standard feature of 4G/LTE networks which allows a device to briefly turn off its RX antenna in order to save battery, however the maximum cycle length is 1.28 or 2.56 seconds. This means your device modem will continue to turn on the RX antenna at this interval to receive data from the network. For many IoT use cases, there is no need to turn on the RX antenna and receive new data so frequently, and doing so negatively affects battery life.

eDRX is a feature of LTE-M and NB-IoT networks which allows this interval to be extended up to about 44 minutes (for LTE-M) and about 175 minutes (for NB-IoT).

PSM is a similar feature, however rather than extending the time between turning on the RX antenna, a modem will keep the RX antenna turned off completely. Because the RX antenna is off, the network cannot reach the device to send any data until the device wakes up again, however this can greatly increase battery life. Using PSM, the interval between waking up can be extended to as long as about 310 hours.

Please note that some LTE-M and NB-IoT networks may not support the maximum eDRX or PSM values.