Power saving mode and eDRX tests for mobile IoT devices
In IoT applications such as container tracking, intelligent meters, or agriculture sensors, the devices do not need to send or receive data continuously. Oliver Wruck, Director MNTS at Comprion, explains: “Being an important member of the mobile ecosystem, we felt the need to test the UICC interface for devices that support PSM and eDRX in order to prevent unpleasant surprises when the devices go live in mobile networks.“
In PSM, the device can switch to a sort of power-off mode for an agreed amount of time. If the device must transmit data, it can wake up without the need of reattaching to the network and the necessary signalling.
eDRX makes it possible to considerably extend the time interval during which the device is not listening to the network. For mobile-terminated traffic, this feature improves power conservation vastly.
In order to assure reliable switching between deactivation and activation of the UICC interface, 3GPP requires the terminals that implement PSM or eDRX functionality to be thoroughly tested from Release 14 on.
Comprion took the lead with the creation of corresponding test cases. “We have drafted eleven tests for the 3GPP Working Group CT6. With their approval, the tests have become part of the test specifications for 3GPP TS 31.121 and 3GPP TS 31.124,“ adds Comprion’s CT6 delegate, Dania Azem.
The validation of the Comprion tests also initiated the activation of two new Global Certification Forum (GCF) work items: WI-301-NB (for NB-IoT devices) and WI-301-M (for LTE CatM1 terminals). Thus, the tests have become part of the GCF certification program. And the North American counterpart PTCRB has also added the tests to their RFTs (Request For Testing), which are the basis for their certification program.
The Comprion PSM and eDRX tests for NB-IoT and LTE Cat M1 devices can be executed on the GCF/PTCRB-listed test platform 150 (SIMfony LTE CMW500). It consists of the Comprion UT³ Platform (SIM simulator) and the R&S CMW500 network simulator. It is also possible to run these tests during the development phase of a device using the Comprion pre-conformance test solution Prove 2 with R&S CMW500.
Comprion – www.comprion.com