A Link-Layer Synchronization and Medium Access Control Protocol for Terahertz-Band Communication Networks

In this paper, a link-layer synchronization and medium access control (MAC) protocol for very-high-speed wireless communication networks in the THz band is presented. The protocol relies on a receiver-initiated handshake as a way to guarantee synchronization between transmitter and receiver. In addition, it incorporates a sliding window flow control mechanism, which combined with the one-way handshake, maximizes the channel utilization. Two different application scenarios are considered, namely, a macroscale scenario, in which nodes utilize turning directional antennas to periodically sweep the space while overcoming the distance problem at THz frequencies, and a nanoscale scenario, in which nano-nodes require energy harvesting systems to operate. A carrier-based physical layer is considered for the macro-scenario, whereas the physical layer for the nano-scenario is based on a femtosecond- long pulse-based modulation scheme with frame interleaving. The performance of the proposed MAC protocol is analytically investigated in terms of delay, throughput and successful packet transmission probability, and compared to that of an adapted Carrier Sense Multiple Access with Collision Avoidance with and without handshake. The results are validated by means of extensive simulations with ns-3, in which all the necessary THz elements have been implemented. The results show that the proposed protocol can maximize the successful packet delivery probability without compromising the achievable throughput in THz-band communication networks.