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.

A QoE preserving M2M-aware hybrid scheduler for LTE uplink

Abstract: The 4th Generation (4G) Long Term Evolution (LTE) wireless networks are expected to be used for the majority of Machine to Machine (M2M) communication. M2M communication over 4G networks faces some challenges. The main challenge is how to accommodate the massive number of M2M devices without negatively impacting the human subscribers' Quality of Experience (QoE). This paper discusses the challenges of scheduling UEs and M2M terminals in LTE networks. The LTE scheduler plays an important role in distributing radio resources to user equipments (UEs) and M2M terminals. We present a hybrid uplink scheduler that balances the radio resources allocation to preserve human users QoE and fairly fulfills M2M terminals communication requests. The simulation results show that the proposed solution provides fair scheduling of M2M terminals without impacting the UE.

Traffic load balance methods in the LTE-Advanced system with carrier aggregation

Abstract: In the further advancements for the third generation (3G) long-term evolution (LTE) system, i.e. the LTE-Advanced system, carrier aggregation (CA) is applied to support wide system bandwidth and ensure backward compatibility. In this paper, two traffic load balance methods are proposed to improve the performance of the independent carrier scheduling (ICS) scheme in CA based LTE-Advanced system with time-variant user population. One is to utilize advanced user allocation rules. The other is a novel method which couples the component carriers (CCs) together in the scenario that the CCs are in the different working states. Our simulation results show that well-designed user allocation rules can achieve better traffic load balance across the CCs than the simplest random allocation rule. Moreover, the CC coupling method can make the ICS scheme achieve optimal performance as the joint carrier scheduling (JCS) scheme, irrespective of the traffic intensity and the used user allocation rule. However, using better user allocation rule can reduce the CC coupling time for the ICS scheme, which is essential to the practicality of ICS.

Multiuser Superposition Transmission (MUST) for LTE-A systems

Abstract: A new study item termed downlink Multiuser Superposition Transmission (MUST) has been established in 3GPP Release 13 [1]. As the name suggests, MUST utilizes the concept of superposition coding for a multiuser transmission in LTE-Advanced (LTE-A) systems. While superposition coding can be applied at symbol level, the symbol-domain superposition coding not only increases network signaling overhead and implementation difficulty, but also causes performance degradation due to non-Gray mapping resulting from the symbol-domain superposition. In this paper, we propose a bit-domain multiuser superposition technique by exploiting the intrinsic properties of bit-interleaved coded modulation (BICM) which is one of key technologies for LTE systems. Simulation results show that the bit-domain MUST can increase both the cell-average and cell-edge user spectral efficiency by more than 20% compared to single-user MIMO (SU-MIMO).

Analyzing and enhancing the resilience of LTE/LTE-A systems to RF spoofing

Abstract: The long-term evolution (LTE) is cellular communications standard that is widely adopted and deployed around the world. It offers high-speed wireless services to meet the increasing demand on user data traffic. LTE technology is also considered for public safety networks. Hence, it is mandatory to ensure that the LTE system can operate in interference-prone environments including targeted interference. We introduce the term LTE control channel spoofing, which refers to transmitting a partial LTE downlink frame, created by a fake eNodeB which does not possess the registration keys nor offers any service. We have built a testbed to demonstrate that this can cause permanent denial of service for UEs that are in cell selection process. This is achieved by sending fake control channel messages rather than authentication attacks. The failure of attachment that is caused by LTE control channel spoofing can be explained in conjunction with the 3GPP specifications. Mitigation techniques are proposed to effectively enhance the robustness of LTE systems and ensure that it is secure and available when and where needed. The recommended modifications to the specifications only require simple changes to UE message handling and are backward compatible with currently deployed LTE networks.

A group-based security protocol for machine-type communications in LTE-advanced

Abstract: Machine-type communication (MTC) takes advantage of millions of devices being connected to each other in sensing our environment. A third-generation partnership project has been actively considering MTC as an enabler for ubiquitous computing and context-aware services. Until recently, we have not yet known how to productively manage the signaling traffic from these MTC devices because authentication requirements may impose such large signaling loads that they overwhelm the radio access of 4G cellular networks. This paper proposes the design of an efficient security protocol for MTC. This protocol is designed to be compatible with the incumbent system by being composed of only symmetric cryptography. Efficiency is attained by aggregating many authentication requests into a single one. The security and performance of the new design are evaluated via formal verification and theoretical analysis. Implementation of the proposed protocol in a real LTE-A network is provided through a feasibility analysis undertaken to prove the practicability of the protocol. Based on these evaluations, we contend that the proposed protocol is practical in terms of security and performance for MTC in LTE-Advanced.