Effective-Capacity-Based Resource Allocation for End-to-End Multi-Connectivity in 5G IAB Networks

In a 5G integrated backhaul and access (IAB) network, an IAB-donor and multiple IAB-nodes form a multi-hop wireless backhaul network. When a terminal is connected to an IAB-node, the traffic flows generated by the terminal can be backhauled to the IAB-donor. Due to the mobility of terminals, access links are error-prone and cause difficulty in ensuring end-to-end quality of service (QoS) of traffic flows. To improve access link reliability, multi-connectivity is considered in IAB, i.e., a terminal is connected to multiple IAB-nodes. However, to ensure end-to-end QoS, multi-connectivity must be considered together with multi-hop backhauling. Thus, an effective-capacity based resource allocation (eReal) scheme is developed to establish end-to-end multi-connectivity. The objective of the scheme is to guarantee end-to-end QoS and ensure outage probability is below the given threshold. Since traffic flows are classified into the guaranteed bit rate (GBR) and the non-GBR types, the scheme is formulated as two joint route selection and resource allocation problems to provide differentiated services with minimum resource consumption. Since both problems are NP-hard, they are solved using column generation. Performance results show that eReal serves various traffic flows with over 95% QoS guarantees and also significantly outperforms existing schemes.