2G/GSM

EC GSM

EC GSM stands for Enhanced Coverage GSM. As it impiles, this technology is deviced to extend the cell coverage of current GSM cell and mainly targeted for IoT application.

The detailed technical description is well explained in 3GPP TR 45.820 6.2 Extended Coverage for GSM (EC-GSM). The basic idea of achieving the extended the coverage is as follows

• For CCCH (Common Control Channel) : It does blind retransmission/repetition
• For data channel : for the data channels, a combination of blind repetitions of the lowest MCS supported in EGPRS today, i.e. MCS-1 and HARQ retransmissions

Main motivation of this technology is to deploy the technology simply by changing the software on existing GSM network and it is designed that this software change does not influence on the device with existing technology. (Of course this is not easy and they need a lot of technical details to be implemented as described in TR 45.820)

Reference :

[1] 3GPP TR 45.820 V13.1.0 (2015-11) - Cellular system support for ultra-low complexity and low throughput Internet of Things (CIoT) (Release 13)

[2] Live IoT Demo: Improving IoT Coverage with Extended Coverage (EC) GSM (YouTube)

[3] Orange and Ericsson announce IoT LTE GSM Trial (YouTube)