Power efficient RACH mechanism for dense IoT deployment

In the world of Internet of Things (IoT), it is desired that every IoT device is able to communicate with the network all the time. Among various technologies to enable network connectivity, Long Term Evolution (LTE) is by far the most ubiquitous technology to provide coverage for IoT devices. The IoT devices are inherently resource constraint and efficient communication is one of the primary requirements of these devices. LTE Random Access Channel (RACH), one of the primary procedures to enable channel access for devices, is well suited for cellular deployment. In this work, we have demonstrated that the current LTE-RACH procedure is not power efficient for dense deployments because in such scenarios RACH failures are mostly due to request collisions and increasing the transmit power does not give any significant advantage. We have also proposed Delayed Power Ramping Algorithm (DPRA), a heuristic based approach to improve the energy footprint of the IoT devices. We have conducted extensive simulations using Network Simulator (ns3) and discussed the performance results of the proposed approach for different scenarios.