In-Band Device-to-Device Communication in OFDMA Cellular Networks: A Survey and Challenges

Pavel Mach, Zdenek Becvar, Tomas Vanek
2015 IEEE Communications Surveys and Tutorials  
Direct communication between two or more devices without the intervention of a base station, known as device-todevice (D2D) communication, is a promising way to improve performance of cellular networks in terms of spectral and energy efficiency. The D2D communication paradigm has been largely exploited in non-cellular technologies such as Bluetooth or Wi-Fi but it has not yet been fully incorporated into existing cellular networks. In this regard, a new proposal focusing on the integration of
more » ... D communication into LTE-A has been recently approved by the 3GPP standardization community as discussed in this paper. In cellular networks, D2D communication introduces several critical issues, such as interference management and decisions on whether devices should communicate directly or not. In this survey, we provide a thorough overview of the state of the art focusing on D2D communication, especially within 3GPP LTE/LTE-A. First, we provide in-depth classification of papers looking at D2D from several perspectives. Then, papers addressing all major problems and areas related to D2D are presented and approaches proposed in the papers are compared according to selected criteria. On the basis of the surveyed papers, we highlight areas not satisfactorily addressed so far and outline major challenges for future work regarding efficient integration of D2D in cellular networks. Index Terms-D2D communication, D2D mode selection, interference management, D2D energy efficiency, advanced topology for D2D 1553-877X (c) Fig. 2. Classification of D2D communication in cellular networks. tion underlying LTE-A network and shown how the D2D communication can be established within a system architecture evolution (SAE). The study introduces an exchange of messages to support the D2D functionality within the SAE and contemplates the possible limits of the D2D concerning interference issues both in the downlink (DL) and the uplink (UL) transmission directions. The paper also presents feasibility analysis evaluating performance of network with enabled D2D communication. Functional prospects of the D2D communication and its implementation into LTE-A system are tackled in [29] . The paper describes new features necessary to be added into the SAE architecture in order to support the D2D communication: radio identification and bearer setup, means to exchange the information over a D2D connection and interference management, link adaptation, timing, and mobility issues. Design aspects of network assisted D2D communication is addressed in [30] . The paper firstly provides a brief overview on technical challenges posed by enabling of D2D concept in cellular networks and provides the solutions for individual challenges. An option of architectural modification in LTE-A networks for D2D is also proposed in [31] . The authors introduce new network entity, called a D2D server (in Fig. 1 , this server is not depicted to keep clarity of the figure), and necessary interfaces to connect it to the existing LTE-A architecture. The D2D server is located within the EPC and interfaces with a (MME), a policy and charging rules function (PCRF), peer D2D servers, and with application servers. The logical functions of the D2D server are, for example, device identifier allocation, policy management, assistance in location, call establishment, or mobility tracking. Further, the paper proposes protocol stack describing protocol termination for the D2D communication. Finally, procedures necessary for establishing and maintaining the D2D connection are introduced. With respect to 3GPP architecture, this D2D server is analogous to ProSe application server with ProSe function. 5 2) D2D discovery: Essential part of the D2D management is a discovery of the DUEs (in literature also known as a peer discovery procedure). The purpose of D2D discovery process is to find the presence of devices that could potentially communicate directly. The overall discovery process can be split into two stages: discovery initiation and discovery control. The D2D discovery can be initiated either before the DUEs start to communicate (labeled as "priori") or during ongoing communication (known as "posteriori") [34] . The common use of priory D2D discovery is a sharing of a specific content between two devices. On the other hand, posteriori D2D discovery could be used, for example, by mobile devices that move to vicinity of each other during data exchange and D2D communication becomes more suitable/efficient. Like overall D2D control (described in Section III-A1), the discovery process can be controlled with different levels of network involvement. Thus, the discovery can be controlled either fully by the network (network assisted D2D discovery) or 1553-877X (c) Fig. 3. Scenarios for D2D communication. B. D2D communication scenarios This section illustrates individual possible scenarios that could be considered for D2D communication. In general, D2D scenarios can be classified by several aspects (see Fig. 2 ) as follows. • Coverage -This aspect distinguishes whether the pair of DUEs is under the coverage of a cellular network. In this context we can categorize D2D communication as: -In coverage -Both DUEs are within the coverage of the cellular network. -Partial coverage -One DUE is in the coverage of the cellular network whereas the second one is out of coverage (e.g., it could be in a coverage hole caused by interferes in the proximity). -Out of coverage -Both DUEs are outside the cellular communication network. Note that this scenario is considered mainly in 3GPP for public safety cases, when the network can be temporarily disabled. • Type of D2D communication -This aspect expresses how many DUEs are involved in D2D communication: -One-to-one communication -Direct communication between two DUEs that creates one D2D communication pair. -One-to-many communication -One DUE multicasts/broadcasts data to several DUEs in a cluster. This option is also labeled device to multi-device (D2MD). 1553-877X (c)
doi:10.1109/comst.2015.2447036 fatcat:otla3xvx4nek3acwev6cxovc2y