Relay-Assisted and QoS Aware Scheduling to Overcome Blockage in mmWave Backhaul Networks

Abstract

In the scenario where small cells are densely deployed, the millimeter wave (mmWave) wireless backhaul network has been widely used. However, mmWave is easily blocked by obstacles, and how to forward the data of the blocked flows is still a significant challenge. To ensure backhauling capacity, the quality of service (QoS) requirements of flows should be satisfied. In this paper, we investigate the problem of optimal scheduling to maximize the number of flows satisfying their QoS requirements with relays exploited to overcome blockage. To achieve a practical solution, we propose a relay-assisted and QoS aware scheduling scheme for the backhaul networks, called RAQS. It consists of a relay selection algorithm and a transmission scheduling algorithm. The relay selection algorithm selects non-repeating relays with high link rates for the blocked flows, which helps to achieve the QoS requirements of flows as soon as possible. Then, according to the results of relay selection, the transmission scheduling algorithm exploits concurrent transmissions to satisfy the QoS requirements of flows as much as possible. Extensive simulations show RAQS can effectively overcome the blockage problem, and increase the number of completed flows and network throughput compared with other schemes. In particular, the impact of relay selection parameter is also investigated to further guide the relay selection.

Resource allocation in mmWave 5G IAB networks: A reinforcement learning approach based on column generation

“…[11] performs routing and scheduling to improve the end-to-end throughput in the wireless backhaul, targeting at urban environments and utilizing 3D models of buildings as primary blockage sources. [22] maximizes the number of protected flows in a wireless backhaul by selecting relay nodes to bypass the blockages when they occur.…”

“…Despite the significant results that have been achieved in literature, the efforts made in dealing with the dynamic blockage scenario characterizing IAB networks are far from being enough. Some of the existing works assume static blockages for specific propagation scenarios [6] or those caused by urban buildings [11], while others assume simple dynamic blockages [9,22]. Indeed, these works either use steady state distribution of the link status to compute an expected metric, which cannot capture frame-by-frame or slotby-slot actual link conditions [9], or make decisions based on the current blockage situation [22], which only aims to maximize the instantaneous throughput of the current time slot, without considering the impact on future time slots.…”

Efficient Hybrid Beamforming With Anti-Blockage Design for High-Speed Railway Communications

“…For a better understanding of the NLoS conditions rising from random blockage effects, various works have targeted on the blockage models and performance analysis [19,20,30]. To combat random blockages in practical scenarios, a variety of solutions have been proposed [30][31][32][33][34][35][36][37].…”

“…From the point of deploying backup TX, alternative APs/BSs can be densely deployed for substitute direct paths from new transmitters to the given RX, and to support diversity switching [30,36,37]. In terms of the RX side, other receivers/nodes can be harnessed as a one-hop or multihop relay, which facilities connection restoration bypassing the obstacles [32,34,35]. For intermediate links, it can turn to NLoS paths, transmission scheduling, and multi-hop routing, to exploit the spatial multiplexing gain [31,33].…”

A Cascaded Multi-IRSs Beamforming Scheme in mmWave Communication Systems

“…Therefore, how to improve the system performance of mmWave system in dense blocked areas is an important issue. There are some traditional solutions, such as deploying small cells [2] and amplify-and-forward (AF) relays [3]- [5] to overcome the blockages. However, these solutions will also bring significant power consumption.…”