LTE Advanced

About: LTE Advanced is a research topic. Over the lifetime, 4055 publications have been published within this topic receiving 74262 citations. The topic is also known as: Long-Term Evolution Advanced & LTE-A.

Dynamic Buffer Status-Based Control for LTE-A Network With Underlay D2D Communication

Abstract: This paper explores the problem of joint mode selection, spectrum management, power control, and interference mitigation for device-to-device (D2D) communication underlaying a Long Term Evolution-Advanced (LTE-A) network. We consider a dynamic mode selection scenario, in which the modes (D2D or cellular) of the devices depend on optimal allocations. To improve the quality of service (QoS) for the users, the optimization objective in a corresponding problem is formulated in terms of buffer size of user equipments (UEs), which is estimated based on buffer status information collected by the UEs. The realizations of a resource allocation approach presented in the paper include its real-time and non-real-time implementations, as well as two modifications applicable to a standard LTE-Direct (LTE-D) network. Performance of the proposed algorithms has been evaluated using the OPNET-based simulations. All algorithms show improved performance in terms of mean packet end-to-end delay when compared to most relevant schemes proposed earlier.

Efficient Handover in LTE-A by Using Mobility Pattern History and User Trajectory Prediction

Abstract: The handover is one of the basic elements in the mobility management of Long Term Evolution Advanced (LTE-A) wireless systems. It permits the user equipment (UE) to wander between LTE-A wireless networks. LTE-A purely depends on the hard handover, which may cause disconnection to occur if the handover is not fast enough. In this paper, an advanced handover technique is proposed, which consolidates the present UE moving direction and its history information. The proposed technique tracks the UE positions to determine its direction. When the UE is close to the handover spot, the UE begins to look into its history, so as to select the target cell. In the event that the UE trajectory does not exist in the history or the load of target cell is full, the UE and its serving cell will begin looking for a target cell through the use of a cosine function and distance in order to select the target cell. Through the direct selection of the evolved NodeB target in the handover, the performance of the network transmission is seen to improve. The proposed algorithm is evaluated and then compared with the 3GPP standard handover and existing work depending on handover number, number of signaling measurements, packet delay ratio, packet loss ratio, and throughput. The simulation with LTE-Sim proves that the proposed algorithm significantly reduced the number of handovers, the signaling measurements number, the packet delay ratio, and the packet loss ratio and increased the throughput.

An End-to-End QoS Performance Evaluation of VoLTE in 4G E-UTRAN-based Wireless Networks

Abstract: Long Term Evolution (LTE) is the Fourth- Generation (4G) mobile broadband technology. Its standardization has been finalized by Third-Generation Partnership Project (3GPP) in Release 8 technical specifications (R8). As users' demand for higher data rate continues to rise, LTE and its ability to cost effectively provide fast, highly responsive mobile data services, a scalable bandwidth and a reduced latency will become ever more important. However, the Evolved Packet Core (EPC) of the Evolved Universal Terrestrial Radio Access Network (E- UTRAN) based wireless networks (LTE and LTE-Advanced) is all-IP Packet-Switched (PS) core network and lacks native support for Circuit-Switched (CS) services. This introduces the problem of how to provide voice services in these networks. The controversy around many of the proposed solutions to provide a PS voice and the effects of this step on the deployment of LTE networks is presented. This paper also deals with the Quality of Service (QoS) in a Voice over LTE (VoLTE) service. It provides a comprehensive evaluation and validation of VoLTE QoS based on the International Telecommunication Union standard Recommendations (ITU- R) and 3GPP standard technical specifications. The initial results obtained give clear evidence that the VoLTE service fulfills the ITU-R and 3GPP standard requirements in terms of end-to-end delay, jitter and packet loss rate. Furthermore, the results related to implementing different LTE bandwidths clearly reflect how these bandwidths affect the overall network performance and end-user experience.

An IP-based packet test environment for TD-LTE and LTE FDD

Abstract: In recent years, Long Term Evolution systems have been developed to replace 3G mobile networks. During LTE network deployment, it is essential that mobile operators and manufacturers conduct tests on user equipment and the base station (eNB). Besides conformance testing at the radio layer, it is also important to conduct network-layer performance tests between UE and eNB. This article develops an LTE test environment that can be used to test the IP-based packet performance for TD-LTE and LTE FDD. Specifically, we consider the latency and the throughput performance of IP, TCP, and VoIP (i.e., G.711) packet delivery. This multi-purpose test environment can be utilized to investigate the performance of the UE and/or eNBs of various manufacturers. Furthermore, we use this environment to compare TD-LTE and LTE FDD. The measurement results provide guidelines for UE and eNB vendors to improve their products, and operators to deploy their LTE networks and subsidized UE devices.

Radio-frequency-based Wireless Energy Transfer in LTE-A heterogenous networks

Abstract: Wireless Energy Transfer (WET) promises charging wireless sensor networks, cell phones and on-body medical devices without the need of battery replacement nor plugging in to the mains. Magnetic induction and electromagnetic radiation are two alternative technologies for WET. Magnetic induction based WET is a mature technology while electromagnetic radiation based WET has been recently studied for WSNs or RFID tags in many studies. On the other hand, powering cell phones, PDAs or other User Equipment (UE) from ambient electromagnetic signals has unique challenges and is an emerging field of study. In this paper, we consider Radio Frequency WET (RF-WET) for prolonging UE lifetime in a Heterogeneous wireless network (HetNet). In a HetNet, coverage and capacity of the macro cell is augmented by small cells such as picocells, femtocells or Wi-Fi hotspots. In this paper, we assume small cell base stations and dedicated Energy Transmission Towers (ETTs) work together towards supplying power to the UEs. Power is supplied in the same frequency band with the communications in a time-sharing manner. We propose an ILP model where a mix of Picocell Base Stations (PBSs) and ETTs are placed such that the harvested energy is maximized while the number of ETTs and the number of actively power transmitting PBSs are minimized. We show that extended range of PBSs aid in increasing the amount of energy harvested by the UEs while as the number of serviced UEs increase the overall power harvesting capacity of the system improves.