Future and current cellular networks encounter an unprecedented growth of mobile devices traffic, imposing various critical challenges that should be thoroughly addressed. Catering for such enormous amount of traffic demand via cellular networks significantly increases the network congestion and degrades the achievable quality of service (QoS). Thus, traffic offloading has been suggested to tackle the expected high growth rate in cellular networks and alleviate the foreseen performance degradation. Most of the previous works in the literature aim to increase the number of offloaded users, and, as a consequence, increase the number of admitted users to the network. However, this has been done without considering users’ traffic load. In this paper, we consider the offloading problem in a HetNet with D2D communication taking into account the traffic load in the network. First, we study the maximization of the total network throughput while maintaining the system queues stability, which is found to be a non-convex problem. Thus, we propose a heuristic offloading algorithm that is shown to achieve comparable performance to that obtained through an exhaustive search algorithm. Additionally, we derived the average delay encountered by the network users packets under such setting. Second, we study the maximization of the total network energy efficiency (EE) while maintaining the network queues stability and the maximum transmit power constraint of each user. The optimization problem aims to find the optimal offloading decision besides the transmit powers of each user in the network according to the obtained offloading decision. We propose another heuristic EE-based offloading algorithm due to the non-convexity of the problem. Numerical simulations demonstrate the effectiveness of the proposed algorithms in outperforming similar algorithms in the literature that do not take into consideration the users’ traffic load into the offloading decision.

未来和当前的蜂窝网络遇到了前所未有的移动设备流量增长，带来了应彻底解决的各种关键挑战。通过蜂窝网络满足如此大量的流量需求会显着增加网络拥塞并降低可实现的服务质量 (QoS)。因此，已经建议流量卸载来解决蜂窝网络中预期的高增长率并缓解可预见的性能下降。文献中以前的大部分工作旨在增加卸载用户的数量，因此，增加了网络准入用户的数量。然而，这是在没有考虑用户流量负载的情况下完成的。在本文中，考虑到网络中的流量负载，我们考虑了具有 D2D 通信的 HetNet 中的卸载问题。首先，我们研究了在保持系统队列稳定性的同时最大化网络总吞吐量，发现这是一个非凸问题。因此，我们提出了一种启发式卸载算法，该算法可以实现与通过详尽搜索算法获得的性能相当的性能。此外，我们推导出了在这种设置下网络用户数据包遇到的平均延迟。其次，我们研究了在保持网络队列稳定性和每个用户的最大传输功率约束的同时最大化网络总能效（EE）。优化问题的目的是根据得到的分流决策，寻找除网络中每个用户的发射功率外的最优分流决策。由于问题的非凸性，我们提出了另一种基于启发式 EE 的卸载算法。数值模拟证明了所提出算法的有效性优于文献中未将用户的流量负载考虑到卸载决策中的类似算法。