Handover measurement is responsible for finding a handover target and directly decides the performance of mobility management. It is governed by a complex combination of parameters dealing with multi-cell scenarios and system dynamics. A network design has to offer an appropriate handover measurement procedure in such a multi-constraint problem. The present paper proposes a unified framework for the network analysis and optimization. The exposition focuses on the stochastic modeling and addresses its key probabilistic events namely (i) suitable handover target found, (ii) service failure, (iii) handover measurement triggering, and (iv) handover measurement withdrawal. We derive their closed-form expressions and provide a generalized setup for the analysis of handover measurement failure and target cell quality by the best signal quality and \st{minimum duration outage} \textit{level crossing properties}. Finally, we show its application and effectiveness in today's 3GPP-LTE cellular networks.
To improve capacity and overcome some of the limitations of cellular wireless networks, drones with aerial base stations can be deployed to assist the terrestrial cellular wireless networks. The mobility of drones allows flexible network reconfiguration to adapt to dynamic traffic and channel conditions. However, this is achieved at the expense of more handovers since even a static user may experience a handover when the drones are mobile. In this letter, we provide an exact analysis of the handover rate and sojourn time (time between two subsequent handovers) for a network of drone base stati…
Offloading computationally intensive tasks from mobile users (MUs) to a virtualized environment such as containers on a nearby edge server, can significantly reduce processing time and hence end-to-end (E2E) delay. However, when users are mobile, such containers need to be migrated to other edge servers located closer to the MUs to keep the E2E delay low. Meanwhile, the mobility of MUs necessitates handover among base stations in order to keep the wireless connections between MUs and base stations uninterrupted. In this paper, we address the joint problem of container migration and base-statio…
In mm-wave networks, cell sizes are small due to high path and penetration losses. Mobiles need to frequently switch softly from one cell to another to preserve network connections and context. Each soft handover involves the mobile performing directional neighbor cell search, tracking cell beam, completing cell access request, and finally, context switching. The mobile must independently discover cell beams, derive timing information, and maintain beam alignment throughout the process to avoid packet loss and hard handover. We propose Silent tracker which enables a mobile to reliably manage h…
Millimeter-wave (mmWave) communication is considered as a key enabler of ultra-high data rates in the future cellular and wireless networks. The need for directional communication between base stations (BSs) and users in mmWave systems, that is achieved through beamforming, increases the complexity of the channel estimation. Moreover, in order to provide better coverage, dense deployment of BSs is required which causes frequent handovers and increased association overhead. In this paper, we present an approach that jointly addresses the beamforming and handover problems. Our solution entails a…
Mobile users in an ultra-dense millimeter-wave cellular network experience handover events more frequently than in conventional networks, which results in increased service interruption time and performance degradation due to blockages. Multi-connectivity has been proposed to resolve this, and it also extends the coverage of millimeter-wave communications. In this paper, we propose a dual-connection based handover scheme for mobile UEs in an environment where they are connected simultaneously with two millimeter-wave cells to overcome frequent handover problems. This scheme allows a mobile UE …
Handover (HO) management has attracted attention of research in the context of wireless cellular communication networks. One crucial problem of HO management is to deal with increasing HOs experienced by a mobile user. To address this problem, HO skipping techniques have been studied in recent years. In this paper, we propose a novel HO skipping scheme, namely, time-based HO skipping. In the proposed scheme, HOs of a user are controlled by a certain fixed period of time, which we call skipping time. The skipping time can be managed as a system parameter, thereby enabling flexible operation of …
Proactive TCP mechanism to improve Handover performance in Mobile Satellite and Terrestrial Networks
正在出现的用于卫星系统的Geo Mobile Radio（GMR-1）的标准化在上层协议层与地面GSM（全球移动通信系统）具有很强的相似性，TCP（传输控制协议）是其中之一。这种空间段技术以及地面技术的特征在于通信特性和覆盖范围的周期性变化，当移动节点（MN）的连接改变随机性时，导致正在进行的呼叫的终止。虽然规定提供有效的通信基础设施，这种混合空间和地面网络必须确保端到端的网络性能，使MN可以在这些网络之间无缝移动。然而，从连接性的角度来看，当前的TCP性能还没有被设计用于多无线电MN中的移动性事件。传统上，TCP采用一套拥塞控制算法（慢启动、拥塞避免、快速拥塞、快速恢复）来探测连接路径上的当前可用带宽，这些算法需要多次往返才能找到正确的传输速率（即拥塞窗口），并适应切换引起的连接性突变。虽然有一些协议，如移动IP（MIP）和主机身份协议（HIP），以保持连接的连续性的移动性事件，TCP性能工程的关注较少。TCP被实现为操作系统中的单独组件，因此通常不知道移动性事件或多无线电通信的性质。本文旨在提高TCP在移动卫星和地面网络中的通信性能。
Information Centric Networking based Handover Support for QoS Maintenance in Cooperative Heterogeneous Wireless Networks
信息网络（NetInf）是一个术语，用于描述不像现代网络那样以节点为中心的网络。顾名思义，信息取代了网络中的节点。在这份报告中，我们提出了一个架构的移动节点的NetInf。我们称之为NetInf Mobile Node。它是为NetInf提出的基本节点架构的扩展。它与基于NetInf和TCP/IP的网络兼容。该架构中的虚拟节点层模块提供对节点的移动性、功耗以及数据中继/存储服务的管理支持。内/外路由器构造路由器（I/O LCTR）是NetInf移动节点中引入的两个功能，用于在NetInf和非NetInf站点之间操作。NetInf移动节点的基本目的是在移动事件期间维持QoS。切换/移交是移动性期间的关键情况，其中正在进行的会话的QoS降级的机会很高。本报告提出了一个这样的情况下，在异构无线网络环境中切换的情况下，通过我们提出的算法，保持应用程序的QoS。
Cooperative Interference Mitigation and Handover Management for Heterogeneous Cloud Small Cell Networks
异构小小区网络已经吸引了很多关注以满足用户爆炸性的数据业务需求。异构云小小区网络（Heterogeneous Cloud Small Cell Network，HCSNet）结合了云计算和异构小小区网络，将有可能在5G移动通信网络中发挥重要作用。然而，随着小小区的大规模部署，同频干扰和切换管理是HCSNet中的两个重要问题，特别是对于小区边缘用户。在这篇文章中，我们研究的问题，合作干扰缓解和切换管理HCSNet。描述了一种将云无线电接入网络与小小区相结合的网络架构。采用一种有效的协作多点（CoMP）分簇方案，利用亲和传播，以减轻小区边缘用户的干扰。提出了一种低复杂度的切换管理方案，并分析了HCSNet中切换管理的信令流程。仿真结果表明，所提出的网络结构、CoMP分簇方案和切换管理方案能够在保证用户服务质量的同时，显著提高HCSNet的容量。
The 5th Generation (5G) New Radio (NR) and beyond technologies will support enhanced mobile broadband, very low latency communications, and huge numbers of mobile devices. Therefore, for very high speed users, seamless mobility needs to be maintained during the migration from one cell to another in the handover. Due to the presence of a massive number of mobile devices, the management of the high mobility of a dense network becomes crucial. Moreover, a dynamic adaptation is required for the Time-to-Trigger (TTT) and hysteresis margin, which significantly impact the handover latency and overall…
Handover (HO) management is one of the most crucial tasks in dense cellular networks with mobile users. A problem in the HO management is to deal with increasing HOs due to network densification in the 5G evolution and various HO skipping techniques have so far been studied in the literature to suppress excessive HOs. In this paper, we propose yet another HO skipping scheme, called periodic HO skipping. The proposed scheme prohibits the HOs of a mobile user equipment (UE) for a certain period of time, referred to as skipping period, thereby enabling flexible operation of the HO skipping by adj…
This report deals with the design of handover schemes for radio access networks (RAN) in 5G networks, using programmable data plane switches. In 5G networks, the NG-RAN architecture splits the Base Band Unit (BBU) into Central and Distributed Units (CU and DU). This structure has created a mid-haul Network, connecting CUs and DUs. The recent advancements in dataplane programmability can be used to enhance system performance. We show how P4 switches can be used to parse the packets between DU, CU, and Back Haul (Core Network) for potential system improvements. In particular, we consider the sce…
With the ever-growing communication demands and the unceasing miniaturization of mobile devices, the Internet of Things is expanding the amount of mobile terminals to an enormous level. To deal with such numbers of communication data, plenty of base stations (BSs) need to be deployed. However, denser deployments of heterogeneous networks (HetNets) lead to more frequent handovers, which could increase network burden and degrade the users experience, especially in traffic hotspot areas. In this paper, we develop a unified framework to investigate the handover performance of wireless networks wit…
Future wireless networks must serve dense mobile networks with high data rates, keeping energy requirements to a possible minimum. The small cell-based network architecture and device-to-device (D2D) communication are already being considered part of 5G networks and beyond. In such environments, network coding (NC) can be employed to achieve both higher throughput and energy efficiency. However, NC-enabled systems need to address security challenges specific to NC, such as pollution attacks. All integrity schemes against pollution attacks generally require proper key distribution and managemen…
The next generation Internet is deemed to be heterogeneous in nature and mobile devices connected to the Internet are expected to be equipped with different wireless network interfaces. As seamless mobility is important in such networks, handover between different network types, called vertical handover, is an important issue in such networks. While proposing standards like Mobile IPv6 (MIPv6) and Proxy Mobile IPv6 (PMIPv6) for mobility management protocols, one important challenge being addressed by IETF work groups and the research community is flow mobility in multi-homed heterogeneous wire…
