Lightweight protocols for LTE M2M networks

LTE M2M device, base station and core network nodes exchange several protocol messages when a device tries to attach in an LTE network. LTE Attach procedure includes the following: mutual authentication of M2M device (UE) and network, computation of various security keys and session establishment. These procedures incur high processing overhead at LTE M2M devices and also create high control plane overhead across the LTE air-interface. As some LTE M2M devices may only send data sporadically, they move to sleep (or idle) state to conserve power. As an M2M device transitions from active to sleep state (or vice versa), additional LTE protocol messages are exchanged for re-authentication and other purposes. We propose a solution that reduces protocol overhead across the LTE air-interface, reduces processing overhead at LTE M2M devices and allows the M2M devices to be in sleep mode for longer duration. This potentially helps to reduce energy consumption at LTE M2M devices. We propose a new (logical) entity in the network that partially simulates state (or context) of the UE for the Attach procedure. This new entity is controlled by the network (operator). UE starts Attach procedure in the usual way. We intercept some of the messages of the Attach procedure at LTE eNodeB and do part of the Attach processing using this new network entity, MME, LTE eNodeB and Authentication Centre. UE and network nodes are mutually authenticated after that. We also compare protocol overhead with the existing protocol and show benefits of this scheme.