Dual Connectivity for LTE-NR Cellular Networks

Abstract

The Dual Connectivity (DC) technology has gained a lot of momentum in the LTE Release 12 as a means to enhance the per-user throughput and provide mobility robustness. Some studies in the literature have discussed a coupling between the LTE and the air interface of the upcoming Fifth Generation (5G) in a DC scenario. That integration may provide some benefits to meet the high throughput demands, reliability and availability requirements of the 5G networks. This paper presents a brief overview of the DC technology considering the inter-generations coupling and discusses some challenges involving Radio Resource Management (RRM) in such scenario.

Dual connectivity for LTE-NR cellular networks in evolved packet system and critical review on challenges in SgNB release

“…Over last decade the number of devices and diversity of services carried by the mobile network requesting both high-quality and high throughput services drastically increased which resulted in a significant growth in mobile traffic. This resulted into improvements of 4G technology but also developing some 5G revolutionary technical innovations like network slicing allowing multiple logical/virtual networks to be created on the top of a common shared physical infrastructure to reach the increased capacity and needs of each group of services [1,2].…”

“…The high user throughput requirements can be achieved by means of Heterogeneous` Networks (HetNets) [2,3]. The HetNets architecture is composed of macro and micro cells.…”

“…One macro cell involves more than one small cell and have therefore bigger coverage compared to small cell. The small cells in this architecture are acting as hotspot areas increasing capacity and help to dispose of some user plane data from the macro cell [2,4,5]. The disadvantage of such a deployment is that the needed number of small cells is higher which significantly increases also the number of mobility procedures like cell reselections and handovers which may result in mobility-related issues.…”

Dual Connectivity for LTE-NR Cellular Networks: Challenges and Open Issues

“…In this context, the Dual Connectivity (DC) technology has been proposed in the Long Term Evolution (LTE) Release 12 specifications by 3rd Generation Partnership Project (3GPP) as one of the most relevant technologies to accomplish even higher per-user throughput and mobility robustness, and load balancing [6]. Given that a User Equipment (UE) is configured with DC, it can be connected simultaneously to two Evolved Node Bs (eNBs): a Master eNB (MeNB) and a Secondary eNB (SeNB), which operate on different carrier frequencies and are interconnected by traditional backhaul links (known as X2 1 interface in accordance with the LTE terminology). These X2-based backhauls are non-ideal in practice, being characterized by a certain latency and limited capacity [4].…”

“…1) This work firstly presents a brief overview of the DC technology based on the concepts presented in [6] and considering the integration between LTE and NR [1]. 2) Furthermore, some challenges involving Radio Resource Management (RRM) techniques in a DC scenario are discussed.…”