Signature-based and energy-efficient device discovery protocol between the internet of things and relay devices in cellular networks

One of the networks that will connect IoTDs to the Internet is cellular networks. The 3rd Generation Partnership Project (3GPP) proposes a connectivity model for cellular networks in which IoTDs connect to the network via relay devices. Due to energy budget constraints, mobility of devices and collision of discovery messages, it is important that they perform discovery with the minimum energy consumption by intermittently sleeping and waking up. The existing device discovery protocols are not energy efficient for this model as they need to continually search their neighbor devices. In this work, signature-based energy efficient relay discovery protocol using Zadoff-Chu sequences has been developed and the generated sequences have been used for pointing the active time intervals of the devices. With the aid of signature-based signalization, IoTDs do not have to search for relay devices because they know when the relays will wake up in the future. Besides, with the designed novel three-stage original period structure, the message collisions have been eliminated. The probabilistic analysis and simulation results show the developed protocol discovers more devices with less energy consumption as well as preventing collisions, as compared with the existing protocols.