You are provided with the abstract of a scientific paper and the abstracts of the papers it references. Your task is to write a Related Work section for the main paper. This section should concisely summarize and integrate the key points from the cited abstracts, reflecting how they relate to the main paper's contributions and context. In your summary, use numerical citation markers like [1], [2], etc., to refer to the corresponding papers.

Main Abstract:
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.

Cited Abstract(s):
[1]: Small cell networks have been broadly regarded as an imperative evolution path for the next-generation cellular networks. Dense small cell deployments will be connected to the core network by heterogeneous backhaul technologies such as fiber, microwave, high frequency wireless solutions, etc., which have their inherent limitations and impose big challenges on the operation of radio access network to meet the increasing rate demands in future networks. To address these challenges, this paper presents an efficient design considered in the iJOIN (Interworking and JOINt Design of an Open Access and Backhaul Network Architecture for Small Cells based on Cloud Networks) project with the objective of jointly optimizing backhaul and radio access network operations through the adoption of SDN (Software Defined Networking). Furthermore, based on this framework, the implementation of several intelligent management functions, including mobility management, network-wide energy optimization and data center placement, is demonstrated.

[2]: Mobility management in cellular networks, such as the Long Term Evolution (LTE) System, relies on a centralized anchor, which depends on both the control plane and data plane. Therefore, mobility management suffers from many limitations such as low scalability and a single point of failure. Distributed Mobility Management (DMM) overcomes previous limitations and can be applied for HetNets or DenseNets. In this paper, we propose Three-Tiered Software Defined Networking (SDN)-based DMM to solve mobility problems and handover in DenseNets such as femtocells, in addition to macrocells. Our proposal reduces overhead signaling through the core network. As a result, it decreases delay and increases throughput over other cellular networks.

[3]: The ongoing efforts in the research, development and standardization of 5G, by both industry and academia, have resulted in the identification of enablers (Software Defined Networks, Network Function Virtualization, Distributed Mobility Management, etc.) and critical areas (Mobility management, Interference management, Joint access-backhaul mechanisms, etc.) that will help achieve the 5G objectives. During these efforts, it has also been identified that the 5G networks, due to their high degree of heterogeneity, high QoS demand and the inevitable density (both in terms of access points and users), will need to have efficient joint backhaul and access mechanisms as well as enhanced mobility management mechanisms in order to be effective, efficient and ubiquitous. Therefore, in this paper, we first provide a discussion on the evolution of the backhaul scenario, and the necessity for joint access and backhaul optimization. Subsequently, and since mobility management mechanisms can entail the availability, reliability and heterogeneity of the future backhaul fronthaul networks as parameters in determining the most optimal solution for a given context, a study with regards to the effect of future backhaul fronthaul scenarios on the design and implementation of mobility management solutions in 5G networks has been performed.
Among the initial efforts for programmable cellular networks, [1] presents a SDCN design considering both the access and backhaul networks, simultaneously. Another recent work in [3] studies the impact of joint access-backhaul on mobility management solutions in 5G networks. Specifically for various QoS flows, different schemes can be used during cell selection based on the number of hops and the available links capacities. [2] presents a three tier SDN-based LTE network design for efficient mobility management. The results shows a significant delay reduction due to reduced signaling during handover event, however it lacks implementation on a system-level LTE simulator that enables to explore further benefits from the resulting integration.