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.

Iterative Multi-Level Soft Frequency Reuse With Load Balancing for Heterogeneous LTE-A Systems

Abstract: This paper deals with the planning of two-layer long-term evolution-advanced cellular systems, taking both the co-tier and cross-tier interference into account. In particular, we propose the novel multi-level soft frequency reuse (MSFR) scheme, where the users in three different regions of a macro/micro cell adopt distinct frequency segments and different transmission power levels. The optimization of power control parameters and cell association with MSFR results in a non-convex problem. We present the iterative-MSFR (I-MSFR) scheme, where the main optimization problem is divided into two sub-problems that can be subsequently solved by means of classical optimization methods. Finally, we propose two simplified schemes that achieve a comparable performance as I-MSFR in terms of utility, cell capacity, and outage conditions. I-MSFR and the simplified schemes have shown better performance than other schemes in the literature.

Optimum Radio Resource Management in Carrier Aggregation Based LTE-Advanced Systems

Abstract: Carrier aggregation (CA) functionality introduces new challenges for radio resource management (RRM) function of network. In this paper, an optimum and efficient RRM algorithm is proposed for Long Term Evolution-Advanced with reduced complexity and compared with the state-of-the-art (SOTA) solutions. The proposed algorithm optimally assigns component carriers, resource blocks, and modulation and coding scheme values to users, based on their channel state information and CA capabilities. Most of the SOTA solutions are based on approximate approaches that have much inferior performance compared to the performance of our proposed optimal solution. Furthermore, performance of the proposed solution has been evaluated using system-level simulations, and results show clearly that the proposed algorithm outperforms the SOTA algorithms in terms of fairness throughput and average cell throughput.

Enabling Device to Device Broadcast for LTE Cellular Networks

Abstract: In recent years, the public safety community has been aligning behind Long Term Evolution (LTE) technology as the basis for next generation public safety networks. Correspondingly, the 3rd Generation Partnership Project (3GPP) standards body has started multiple technical work initiatives on LTE enhancements to better support public safety use cases and requirements. Of particular importance to the public safety community is the addition of direct device-to-device (D2D) broadcast capability that can enable off-network push-to-talk (PTT) group communications in a manner equivalent to existing public safety communication systems. In this paper, we briefly explore the design objectives for, and challenges associated with, providing a D2D broadcast service. We then present and analyze a new distributed media access control (MAC) scheme for interference-aware coordination of both unicast and broadcast transmission. System-level simulation results are provided to validate the performance and the effectiveness of our approach, using a CSMA-based approach as a basis for comparison.

Mobility and Handover Management for Heterogeneous Networks in LTE-Advanced

Abstract: 3GPP Long Term Evolution-Advanced (LTE-A) aims at enhancement of LTE performance in many respects including the system capacity and network coverage. This enhancement can be accomplished by heterogeneous networks (HetNets) where additional micro-nodes that require lower transmission power are efficiently deployed. More careful management of mobility and handover (HO) might be required in HetNets compared to homogeneous networks where all nodes require the same transmission power. In this article, we provide a technical overview of mobility and HO management for HetNets in LTE-A. Moreover, we investigate the A3-event which requires a certain criterion to be met for HO. The criterion involves the reference symbol received power/quality of user equipment (UE), hysteresis margin, and a number of offset parameters based on proper HO timing, i.e., time-to-trigger (TTT). Optimum setting of these parameters are not trivial task, and has to be determined depending on UE speed, propagation environment, system load, deployed HetNets configuration, etc. Therefore, adaptive TTT values with given hysteresis margin for the lowest ping pong rate within 2 % of radio link failure rate depending on UE speed and deployed HetNets configuration are investigated in this article.

Non-access-stratum request attack in E-UTRAN

Abstract: Long Term Evolution (LTE) is the evolution of Universal Mobile Telecommunications System (UMTS). LTE revises and improves system architecture from UMTS to provide services that are more efficient. Evolved-UTRAN (E-UTRAN) is the air interface of 3GPP and it is on the upgrade path for LTE mobile networks. E-UTRAN specifies better security architecture to protect users' information. However, E-UTRAN is still not perfect. This article studies vulnerabilities of non-access-stratum (NAS) of E-UTRAN. We present illustrative attacks to exploit such vulnerabilities and demonstrate the effectiveness and the impact of such attacks on normal users by using our self-developed simulation tool.