Please note! This essay has been submitted by a student.
Device-to-Device communication is a new technology that offer many advantages for the LTE advanced network such us wireless peer-to-peer services and higher spectral efficiency. It is also considered as one of promising techniques for the 5G wireless communications system and used in many different fields such as network traffic offloading, public safety, social services and applications such as gaming and military applications . The goal of this paper is to present advances on the current 3GPP LTE-advanced system related to Device-to-Device (D2D). In this paper, we provide an overview of the D2D types based on the communication spectrum of D2D transmission, namely Inband D2D communication and Outband D2D communication. Then we present the advantages and disadvantages of each D2D mode. Moreover, architecture and protocol enhancements for D2D communications under LTE-A network are described.
With the explosive growth of mobile devices and bandwidth hungry applications such as video streaming and multimedia file sharing, user demands for mobile broadband are undergoing an unprecedented rise, which pushes the limits of current 4G LTE systems. To improve spectrum efficiency and user experience, device-to-device (D2D) communications underlaying LTE networks have been proposed as a promising approach to facilitate high data rate services in a short range and boost the performance of LTE systems for future 5G communications and beyond.
D2D communication is also recognized as one of the technology components of the evolving 5G architecture by the European Union project METIS. METIS stands for Mobile and wireless communications Enablers for the Twenty-twenty Information Society. The main objective of the project is to lay the foundation of 5G, the next generation mobile and wireless communications system. The METIS project is currently evaluating the role that D2D technology can play in various scenarios such as vehicle-to-vehicle communication; national security and public safety, cellular network offloading or service advertisement.
With the prevalence of various mobile devices, wireless traffic has increased rapidly over the last decade. The huge demand for Internet access has resulted in network congestion and thus performance degradation. Meanwhile, traditional wireless networks, such as Wi-Fi, 3G or 4G, have limited capabilities to handle heavy traffic in highly dense networks. Further, wireless resources may be distributed unevenly, such that many valuable resources remain underutilized in traditional networks. Clearly, network performance may be boosted if the potential valuations of such idle resources are leveraged. D2D communication, which realizes direct wireless data traffic between two devices in proximity, while being controlled by a central entity, is one possible solution to improve resource efficiency and overall network performance. D2D communication has multiple advantages over traditional techniques.
It can realize direct transmission for users in a distributed manner, and achieve high data rates and low energy consumption. Further, spatial reuse of scarce bandwidth can be widely applied in D2D communication to improve spectrum efficiency. It also provides opportunities to handle heavy traffic in areas with high density, such as stadiums, concert, buildings, etc. Additionally, D2D communication can guarantee efficient performance for applications such as content sharing, gaming, coverage improvement, traffic offloading, disaster relief, etc.. D2D communication, due to its nature of decentralized communication, relies heavily on users’ participation. To leverage the advantages of D2D communication, the involvement of both transmitter and receiver is necessary. This is different from cooperative networks, where participants usually have to both receive and transmit data.
In D2D communication, receivers are not necessarily cooperative, and the QoS they experience determines whether they communicate in D2D mode. Hence, to promote D2D communication and build up an efficient D2D network, motivating the participation of mobile users is an essential issue for D2D implementation. Among existing approaches, providing incentives is one of the most popular to motivate mobile users. Since participation incurs energy, time, and data usage, without any kind of incentives, mobile users are more likely not to participate and contribute in D2D communication.
In the existing system, it investigates the underlaid D2D communications in the unlicensed spectrum. Note that different from most previous peer-to-peer communication technologies in the unlicensed spectrum such as Wi-Fi Direct , which builds the network upon the IEEE 802.11 infrastructure mode and allows users to negotiate with each other in an AP-like method, D2D-U requires assist and control from the central BS. With the involvement of BS, D2D users can work as an underlay of LTE system in both licensed and unlicensed spectra.
In this paper we propose a network controlled algorithm to maximize the cellular network spectrum reuse and to provide high performance for D2D users . The cellular network advanced management features to control D2D communication in order to improve the efficiency and reliability of D2D communications and to improve also the system performance in terms of throughput, power efficiency and multicast.
Device-to-Device (D2D) communication is a new technology that offer many advantages for the LTE advanced network such us wireless peer-to-peer services and higher spectral efficiency. It is also considered as one of promising techniques for the 5G wireless communications system and used in so many different fields such as network traffic offloading, public safety, social services and applications such as gaming and military applications . The goal of this paper is to present advances on the current 3GPP LTE-advanced system related to Device-to-Device (D2D). In this paper, we provide an overview of the D2D types based on the communication spectrum of D2D transmission, namely Inband D2D communication and Outband D2D communication.
In this paper, We present the different categories of D2D communication called Inband and Outband , we discuss related work and the different modes of each category .We also discussed the weaknesses and strength for each category. Finally ,we give a description of entities, interfaces, and protocols for the D2D communication architecture under LTE-A network based on LTE SAE architecture. We focus on the innovative architecture of D2D currently examined by 3GPP for integrating D2D communications in LTE-A networks. In this paper, we investigate the D2D-U technology, in which the D2D users operate as an underlay to the LTE system in both licensed and unlicensed spectra. A duty cycle based protocol is designed for LTE-U and D2D-U users while protecting the existing Wi-Fi systems. Considering the complicated mutual interference between LTE, D2D, and WiFi systems, we study the subchannel allocation problem for D2D and LTE users sharing both licensed and unlicensed sub channels to leverage the performance degradation in Wi-Fi systems and the maximization of the sum-rate in LTE/D2D networks.
Specifically, we formulate the allocation problem as a many-to-many matching game with externalities, and develop a low-complexity user sub channel swap matching algorithm. In addition, power control can be done in parallel with sub channel assignment. Analytical and simulation results show that enabling D2D-U communications can significantly improve the system sum-rate. Besides, the subchannel allocation strategy for LTE U and D2D users is closely related to how the BS adjusts the interference to Wi-Fi systems. In an aggressive strategy where the Wi-Fi performance degradation is not considered seriously, the BS allows more D2D and LTE users to transmit on the unlicensed spectrum. On contrary, in a Wi-Fi friendly strategy, the BS tends to permit only a small fraction of D2D users to transmit on the unlicensed spectrum.