LTE-Advanced (LTE-A) offloading is concerned about alleviating traffic congestion for the LTE-A network, which includes the core network and the radio access network (RAN). Due to the scarcity of the radio resource, offloading for the LTE-A RAN is more critical, for which an efficient way is to integrate Wi-Fi with LTE-A to form a heterogeneous RAN environment. An LTE-A UE (User Equipment) with the wi-fi interface can therefore access the Internet via an LTE-A base station of Evolved Node B (eNB) or a wi-fi Access Point (AP). In this paper, wireless network selection for UEs with delay-sensitive traffic in the heterogeneous RAN of LTE-A and wi-fi is addressed. Based on the queueing model of M/G/1, a novel network selection and offloading scheme, namely Delay-Sensitive Network Selection and Offloading (DSO), is proposed. The average system time at LTE-A eNBs and wi-fi APs calculated according to M/G/1 is used for network selection as well as offloading operations in DSO. The benefit of DSO in terms of satisfying the delay budget of UEs and load balancing is demonstrated by the simulation study.

中文翻译：

---

LTE-A 和 Wi-Fi 异构网络中的延迟敏感网络选择和卸载

LTE-Advanced (LTE-A) 卸载关注减轻 LTE-A 网络的流量拥塞，其中包括核心网络和无线接入网络 (RAN)。由于无线资源的稀缺性，LTE-A RAN的分流更为关键，一个有效的方法是将Wi-Fi与LTE-A集成，形成异构的RAN环境。因此，具有 wi-fi 接口的 LTE-A UE（用户设备）可以通过演进节点 B（eNB）的 LTE-A 基站或 wi-fi 接入点（AP）接入互联网。在本文中，解决了在 LTE-A 和 wi-fi 的异构 RAN 中具有延迟敏感流量的 UE 的无线网络选择问题。基于M/G/1的排队模型，提出了一种新颖的网络选择和卸载方案，即延迟敏感网络选择和卸载(DSO)。根据 M/G/1 计算的 LTE-A eNB 和 wi-fi AP 的平均系统时间用于网络选择以及 DSO 中的卸载操作。仿真研究证明了 DSO 在满足 UE 的延迟预算和负载平衡方面的优势。