Device-to-device communication underlaying converged heterogeneous networks

Amila Tharaperiya Gamage, Hao Liang, Ran Zhang, Xuemin Shen
2014 IEEE wireless communications  
To satisfy the ever-increasing wireless service demand, it is effective to form a converged network by utilizing interworking mechanisms, such that the resources of heterogeneous wireless networks can be allocated in a coordinated and efficient manner. Despite the potential advantages of a converged network, its performance needs further improvement, especially at cell edges and rural areas where only one network is available. In this article, we investigate how to leverage device-to-device
more » ... ) communication to further improve the performance of a converged network which consists of an LTE-Advanced (LTE-A) cellular network and IEEE 802.11n wireless local area networks (WLANs). Three main technical challenges which complicate the resource allocation are identified: allocation of resources capturing diverse radio access technologies of the networks, selection of users' communication modes for multiple networks to maximize hop and reuse gains, and interference management. To address these challenges, we propose a resource allocation scheme that performs mode selection, allocation of WLAN resources, and allocation of LTE-A network resources in three different time-scales. The resource allocation scheme is semi-distributedly implemented in the D2D communication underlying converged network, and the achievable performance improvements are demonstrated via simulation results. Index Terms Cellular network, converged heterogeneous networks, D2D communication, hop gain, interference management, interworking, mode selection, multi-homing, resource allocation, reuse gain, wireless local area network (WLANs). I. INTRODUCTION Recent advancements in mobile industry have dramatically increased the number of smart mobile devices (e.g., smart phones and tablets) operating in any geographical region and the number of data hungry applications (e.g., video streaming, YouTube and Google Maps) that run on these devices. Consequently, the demand for higher data rates with seamless service coverage and support for various applications' diverse quality-of-service (QoS) requirements has been increased than ever before. To satisfy these high service demands, it is necessary to efficiently utilize the resources available in heterogeneous wireless networks. Most of the high service demanding areas, such as office buildings, hotspots and airports, are covered by multiple wireless networks, such as Long Term Evolution (LTE) cellular networks and IEEE 802.11n wireless local area networks (WLANs). These networks offer different advantages based on their diverse radio access technologies. For example, cellular networks support high mobility and guarantee QoS while WLANs provide much higher data rates at a lower charge [1] . Therefore, by forming a converged network utilizing interworking mechanisms [2], resources available in these heterogeneous networks can be jointly allocated in an optimal manner to improve the data rates and QoS support [1], [3], [4] . Further, such joint resource allocation widens the coverage area by effectively merging the individual network coverage areas. In a converged network, multi-homing capability of user equipments (UEs) allows users to simultaneously communicate over multiple networks using the multiple radio interfaces available at UEs. With UE multihoming, resource utilization can be further optimized as the user requirements can be satisfied using resources from multiple networks [3] . A converged network may not provide the enhanced network performance at areas such as cell edges or rural areas where only one network is available. Device-to-device (D2D) communication can be applied in these areas to improve the network performance as it allows direct communication between source and destination UEs which are in proximity, and by incorporating hop and reuse gains to the network [5] . Hop gain is a result of D2D links using either uplink (UL) or downlink (DL) resources only. Reuse gain is achieved by simultaneously using the same set of resources for both traditional (i.e., relaying communications via base stations) and D2D links. Therefore, to achieve network performance improvements throughout the converged network, D2D communication can be enabled in the converged network. Enabling D2D communication in a converged network provides two more important benefits. First, high capacity D2D links can be setup between the users who are not within a WLAN coverage by
doi:10.1109/mwc.2014.7000977 fatcat:lpxn46hk4fectbfqjlwzf5otvq