Optimal Link Scheduler for Wireless Backhaul Networks

Increases Network Throughput by Scheduling the Best Concurrent Links in Both Centralized and Distributed Network Schemes

This link scheduling protocol maximizes the quality of service (QoS) benefits while minimizing contentions among links under the directional antennas in wireless backhaul heterogeneous cellular networks. The demand for mobile data is rapidly growing; some estimates predict a 1,000-fold increase by 2020. Heterogeneous cellular networks are emerging as candidates to meet this demand. The numerous small cells of heterogeneous cellular network require a robust backhaul system to function properly. A wireless backhaul system in millimeter waves (mmWaves), which correspond to radio band frequencies of 30 to 300 GHz, is the most promising heterogeneous cellular network as it provides high data rates while being flexible, cost-effective, and easy to deploy. Directional antennas enable communication with reduced interference in the mmWave band. Typically, two goals conflict in the scheduling of links between these antennas. Network capacity can increase due to the spatial reuse gain from exploiting concurrent data transmissions, but this can cause the QoS for links in the network to drop.

Researchers at the University of Florida have developed what they call a “Regret Benefit Ratio” indicator and a link scheduler that utilizes the Regret Benefit Ratio to provide optimal link scheduling. This maximizes the number of links while maintaining their respective QoS requirements to increase network capacity. UF’s proposed “Regret Benefit Ratio Scheduler” and “Distributed Regret Benefit Ratio Scheduler” find the best concurrent links in both centralized and distributed network scenarios.

Application

Link scheduling protocol for increased capacity in wireless backhaul networks

Advantages

• Maximizes the number of concurrent transmissions while satisfying their quality of service requirements, providing optimal link scheduling for wireless backhaul networks with directional antennas
• Functions with both time-slot-based, centralized control network systems and distributed control carrier-sense, multiple access-based network systems, achieving more successfully scheduled links and greater network throughput

Technology

University of Florida researchers have created the Regret Benefit Ratio, an indicator that incorporates the two key objectives that exist within link scheduling conflicts, namely, the maximization of the quality of service (QoS) and minimization of contention among the directional antennas. For a centralized control mmWave network, the Regret Benefit Ratio Scheduler uses the Regret Benefit Ratio to schedule concurrent groups of links to single time slots, improving the total throughput of the network. For a network of the distributed carrier-sense multiple access with collision avoidance framework, the Distributed Regret Benefit Ratio Scheduler collects contention information and uses the Regret Benefit Ratio to optimize QoS and contention throughout the network and maximize network capacity.