Future cellular networks will be dense and require key traffic management technologies for fine-grained network control. The problem gets more complicated in the presence of different network segments with bottleneck links limiting the desired quality of service (QoS) delivery to the last mile user. In this work, we first design a framework for software-defined cellular networks and then propose new mechanisms for management of QoS and non-QoS users traffic considering both access and backhaul networks, jointly. The overall SDN-LTE system and related approaches are developed and tested using network simulator in different network environments. Especially, when the users are non-uniformly distributed, the results shows that compared to other approaches, the proposed load distribution algorithm enables at least 6 and 23 increase in the average QoS user downlink throughput and the aggregate throughput of 40 users with lowest throughput (edge users), respectively. Also, the proposed system efficiently achieves desired QoS and handles the network congestion without incurring significant overhead.
@cite_18: The growing data traffic demand is forcing network operators to deploy more base stations, culminating in dense heterogeneous networks that require a high-connectivity backhaul. This scenario imposes significant challenges for current and future cellular networks, and Software Defined Networking (SDN) has been pointed as an enabling technology to overcome existing limitations. This paper shows how the OpenFlow protocol can be integrated into existing Long Term Evolution (LTE) networks to provide the required Quality of Service (QoS) in the network infrastructure. Three OpenFlow-based mechanisms are proposed: a traffic routing, an admission control function, and a traffic coexistence mechanism. Together, they can effectively control the bandwidth usage in the backhaul infrastructure, improving the QoS and ensuring a better user experience. Simulations were performed to validate the proposed mechanisms and highlight the benefits that can be achieved with the flexibility offered by the SDN technology.
@cite_16: Despite the research community's extensive research towards the advancement in cellular communications, it nevertheless remains an irresolvable problem until now to tackle link congestion. Congestion in communication links may be due to traffic overload and or link failures and or node failures when we consider the wireless backhaul infrastructure of the network operators. While the physical layer technologies have evolved providing high-capacity air-interfaces, network devices have improved in computational power and a vast amount of exciting applications have emerged, the backhaul network architecture in its structure has not seen much change from its early days. With this as starting point, in this paper we claim that with a few "intelligent" design changes within the backhaul architecture of network operators incorporating OpenFlow protocol within the access and aggregation nodes, tackling congestion in communication links, thus becomes achievable.
@cite_18 @cite_16 , SDN based backhaul network management is considered. A recent effort of SDN-based backhaul is made in @cite_18 , where the authors proposed an OpenFlow based mechanism to prioritize traffic and control rate in LTE network. The essence of their work enables backhaul networks to guarantee the rate for GBR traffic during congestion due to the bottleneck link. Similarly, the work in @cite_16 proposes an approach to tackle backhaul network congestion by utilizing OpenFlow. The main purpose of using a programmable backhaul is to allow network operators to share each others network infrastructure to achieve flexibility upon congestion.