Dynamic Beamwidth Selection-Based THz MAC Protocol for Wireless Data Center Networks

Terahertz (THz) wireless communication is a promising solution aimed to solve the problems of wired data centers (DCs). THz has the capability of providing ultra-high data rate up to terabit-per-second (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$T$</tex>b/s) with low latency communication in μs. Additionally, it offers flexibility, efficiency, scalability, and it has a high resource utilization compared to wired links. However, despite these advantages, THz suffers from high path loss because of which directional antennas (DAs) are used. These DAs creates deafness issues for which rotating DAs are used at both ends of transmitter and receiver nodes. These rotating DAs further bring about a synchronization problem at the link layer for Medium Access Control (MAC) protocol. In this regard for timely coordination between the nodes, receiver-initiated THz MAC protocols have been proposed. However, these protocols have used fixed beamwidth which provides high throughput when using wider beams but at the cost of lower range leading to less node's discovery in the DC topology. Hence to address this problem, we propose a receiver-initiated THz MAC protocol named as Dynamic Beamwidth Selection based THz MAC protocol (DBS-ADAPT). Our protocol selects wider beamwidth during the data transmission phase while maintaining the link connectivity between the nodes through exchange of node position/distance which ensures communication range is not compromised while using wider beamwidth. We evaluate the performance of our proposed protocol using NS3 THz network simulator Terasim. Results show that our protocol outperforms the ADAPT-3 THz MAC protocol in terms of throughput and packet time.