M2M wake-ups over cellular networks: over-the-top SIP

Machine-to-Machine (M2M) communication devices are expected to work without recharging for several years. To receive a network-initiated transmission and to lower energy consumption, an M2M modem waits in the idle state and is woken up, when needed. The state-of-the-art M2M wake-up implementation over cellular networks is Short Message Service (SMS). SMS is a Circuit Switched service, which is not present in its original form in Packet Switched LTE. Therefore, we propose an Over-the-Top Session Initiation Protocol (OTT SIP) wake-up method. In this paper, we have implemented OTT SIP as well as SMS over GSM and LTE wake-up methods on a real testbed, connected to a mobile network. We have measured delay and energy consumption. Our measurement results are presented and analyzed in this paper. We also show that OTT SIP wake-up features three times lower delay than SMS over LTE.1