M-T2F: A High-Efficient Contention Protocol for Wireless Networking in Cyber-Physical-Social Systems

Cyber-physical-social systems (CPSS) as an emerging computing paradigm are revolutionizing the relationship between humans, devices and physical environments and will be expected to have a fundamental impact and influence in our daily lives. In a typical CPSS scenario, plenty of nodes (or devices) often adopt wireless distributed contention protocols to transmit sensed environment states for decision making. Therefore, designing a high-efficient and collision-less contention protocol is of great importance for wireless networking. As is known, in the classic time-to-frequency (T2F) protocol, each node signals on one randomly chosen subcarrier for contention. Though reducing the conventional time-domain contention time, T2F leads to many contention collisions (i.e., multiple nodes choose the same subcarrier) when the number of nodes is large. Aiming at this challenge, in this paper, we propose M-T2F (where each node signals on multiple randomly chosen subcarriers for contention) and analyze its consensus achievement. Specifically, M-T2F supports more nodes for transmission but introduces less collision, benefiting from lots of multicarrier choice combinations. Since the subset relationship between subcarrier choices poses a challenge to reach a consensus among nodes, M-T2F enables all nodes to reach a consensus by excluding the subset relationship and reduces contention time by utilizing wireless broadcast characteristi