Release assistance indication %RAI

The Nordic-proprietary %RAI command enables and disables Release Assistance Indication (RAI) support.v1.3.x

In LTE, a device is not allowed to leave a power consuming connection by its own decision. The %RAI command enables support for the RAI feature where the device can indicate when it does not need the data connection anymore. The %RAI command sets on support for protocols, which means that the modem indicates to the network that it supports the RAI feature when connections are set up. The RAI feature can be used if also the network supports it.

In addition to using the %RAI command, the application must tell when the data connection is not needed anymore through the application domain data socket interface. With the interface, the information can be given with the last data packet that is sent or after the application has received the data packet that ends the need for the connection. Each socket client tells their own need for the connection, and the information is combined in the modem domain.

Note: Do not use %XRAI if %RAI is used.