How to Select PSM, DRX, and eDRX

PSM

In PSM mode, the delay of downstream services is not restricted. Downstream service messages can be sent after a device sends upstream data and enters the connected state. This decreases device power consumption.

Immediate delivery (expireTime=0): The IoT platform delivers commands immediately. If a device is in PSM mode, the device cannot receive the commands. Only devices in the active or idle state can receive the commands.

Cache delivery (expireTime>0): The IoT platform caches the received commands. When a device reports data, the IoT platform delivers all cached commands in sequence.

DRX

In DRX mode, the delay of downstream services is strictly restricted. To use this mode, a device must be always online so that messages can be delivered immediately.

Immediate delivery (expireTime=0): The IoT platform delivers received commands immediately without waiting.

Cache delivery (expireTime>0): The IoT platform caches received commands and delivers the command in sequence based on the sequence in which the commands are placed in the queue. After the previous command is sent to the device or times out (the timeout interval is fixed), the IoT platform delivers the next command.

eDRX

In eDRX mode, the delay of downstream services is strictly restricted. In this mode, messages can be sent immediately or buffered based on system configuration.

Immediate delivery (expireTime=0): The IoT platform delivers received commands immediately, and devices can receive the commands.

Cache delivery (expireTime>0): The IoT platform caches received commands and delivers the command in sequence based on the sequence in which the commands are placed in the queue. After the previous command is sent to the device or times out (the timeout interval is configurable), the IoT platform delivers the next command.