SDN‐DMM for intelligent mobility management in heterogeneous mobile IP networks

Mobility management applied to the traditional architecture of the Internet has become a great challenge because of the exponential growth in the number of devices that can connect to the network. This article proposes a Software‐Defined Networking (SDN)‐based architecture, called SDN‐DMM (SDN‐Distributed Mobility Management), that deals with the distributed mode of mobility management in heterogeneous access networks in a simplified and efficient way, ensuring mainly the continuity of IP sessions. Intent‐based mobility management with an IP mapping schema for mobile node identification offers optimized routing without tunneling techniques, hence, an efficient use of the network infrastructure. The simplified mobility control API reduces both signaling and handover latency costs and provides a better scalability and performance in comparison with traditional and SDN‐based DMM approaches. An analytical evaluation of such costs demonstrated the better performance of SDN‐DMM, and a proof of concept of the proposal was implemented in a real environment.     

A survey and comparative study of QoS aware broadcasting techniques in VANET

Mobile operators currently encounter numerous challenges caused by the centralized architecture of mobile networks. A single mobility anchor placed at the network core maintains the entire mobility and data traffic forwarding in the existing centralized mobility management (CMM) solutions. The CMM approach confronts several issues in scalability, reliability, signaling overhead, and non-optimal routing due to the increasing number of mobile devices and the volume of data traffic. To overcome these issues, a new architectural paradigm called distributed mobility management (DMM) is proposed to flatten the network architecture by moving mobility anchors closer to users and separating the control and data planes at the network edge. Two DMM solutions are developed: partially distributed mobility management (partial-DMM) in which only the data plane is distributed and fully distributed mobility management (full-DMM) where both control and data planes are distributed, which can be potentially applied for future mobile networks. This paper presents a network-based full-DMM scheme that was developed and implemented using NS2 network simulator by removing any dedicated centralized mobility anchor from the architecture. Extensive simulations were conducted to evaluate and compare the performance of the full-DMM model with that of the traditional CMM model. The simulation results show that the full-DMM provides lower end-to-end delay performance than CMM. However, the full-DMM generates higher handover latency and packet loss than CMM at high MN speeds. Moreover, simulation results clearly show the benefits of dynamic mobility activation in the full-DMM model.     

Fast handover solution for network-based distributed mobility management in intelligent transportation systems

The current IP mobility protocols are called centralized mobility management (CMM) solutions, in which all data traffic and management signaling messages must be forwarded to an anchor entity. In some vehicle scenarios, vehicles may move as a group from one roadside unit to another (i.e., after traffic lights or traffic jams). This causes data traffic and exchanged mobility messages to peak at the anchor entity and, consequently, affects the network performance. A new design paradigm aimed at addressing the anchor entity issue is called distributed mobility management (DMM); it is an IETF proposal that is still being actively discussed by the IETF DMM working group. Nevertheless, network-based DMM is designed based on the well-known network-based CMM protocol Proxy Mobile IPv6 (PMIPv6). There is no significant difference between network-based DMM and PMIPv6 in terms of handover latency and packet loss. Because vehicles change their roadside unit frequently in this context, the IP addresses of mobile users (MUs) require fast IP handover management to configure a new IP address without disrupting ongoing sessions. Thus, this paper proposes the Fast handover for network-based DMM (FDMM) based on the Fast Handover for PMIPv6 (PFMIPv6). Several modifications to PFMIPv6 are required to adapt this protocol to DMM. This paper specifies the necessary extensions to support the scenario in which an MU has old IP flows and hence has multiple anchor entities. In addition, the analytic expressions required to evaluate and compare the handover performance of the proposed FDMM and the IETF network-based DMM have been derived. The numerical results show that FDMM outperforms the IETF network-based DMM in terms of handover latency, session recovery and packet loss at the cost of some extra signaling.     

SDN/NFV‐based handover management approach for ultradense 5G mobile networks

With the great increase of connected devices and new types of applications, mobile networks are witnessing exponential growth of traffic volume. To meet emerging requirements, it is widely agreed that the fifth‐generation mobile network will be ultradense and heterogeneous. However, the deployment of a high number of small cells in such networks poses challenges for the mobility management, including frequent, undesired, and ping‐pong handovers, not to mention issues related to increased delay and failure of the handover process. The adoption of software‐defined networking (SDN) and network function virtualization (NFV) technologies into 5G networks offers a new way to address the above‐mentioned challenges. These technologies offer tools and mechanisms to make networks flexible, programmable, and more manageable. The SDN has global network control ability so that various functions such as the handover control can be implemented in the SDN architecture to manage the handover efficiently. In this article, we propose a Software‐Defined Handover (SDHO) solution to optimize the handover in future 5G networks. In particular, we design a Software‐Defined Handover Management Engine (SDHME) to handle the handover control mechanism in 5G ultradense networks. The SDHME is defined in the application plane of the SDN architecture, executed by the control plane to orchestrate the data plane. Simulation results demonstrate that, compared with the conventional LTE handover strategy, the proposed approach significantly reduces the handover failure ratio and handover delay.     

Performance Analysis on Network-Based Distributed Mobility Management

Recently, various efforts from both industry and academia are being performed on specifying distributed mobility management (DMM). One of the early and promising network-based DMM proposals is dynamic mobility anchoring (DMA). This paper carries out a performance analysis on DMA in terms of mobility costs and handover performance, comparing it with proxy mobile IPv6 (PMIPv6). For the cost analysis, we consider signaling, processing, data packet delivery, and tunneling costs. For the handover analysis, we consider handover latency, handover failure probability, and handover packet loss as performance metrics. The impacts of several parameters on the mobility costs and handover performance are investigated. The results show that DMA outperforms PMIPv6 significantly in optimizing the network resources consumption as well as the mobility management performance.     

A distributed mobility control scheme in LISP networks

The locator identifier separation protocol (LISP) has been made as an identifier-locator separation scheme for scalable Internet routing. However, the LISP was originally designed for fixed network environment, rather than for mobile network environment. In particular, the existing LISP mobility control schemes use a centralized map server to process all the control traffics, and thus they are intrinsically subject to some limitations in mobile environment, such as large overhead of mapping control traffics at central map server and degradation of handover performance. To overcome these problems, we propose a distributed mobility control scheme in LISP networks. In the proposed scheme, we assume that a mobile host has a hierarchical endpoint identifier which contains the information of its home network domain. Each domain has a distributed map server (DMS) for distributed mapping management of Endpoint Identifiers (EIDs) and Locators (LOCs). For roaming support, each DMS maintains a home EID register and a visiting EID register which are used to keep the EID-LOC mappings for mobile hosts in the distributed manner. For performance analysis, we compare the control traffic overhead (CTO) at map servers, the signaling delay required for EID-LOC mapping management, and the handover delay for the existing and proposed schemes. From numerical results, it is shown that the proposed distributed scheme can give better performance than the existing centralized schemes in terms of CTO, total signaling delay for EID-LOC mapping management, and handover delay.     

A New Enhanced Fast Handover Algorithm in Hierarchical Mobile IPv6 Network

1　Introduction　MobileIPv6requirestheMobileNode (MN)toregisterwiththeHomeAgent (HA)andtheCorre spondentNode (CN)whenitchangesitspointofattachmentintheInternet[1～ 3] .Therefore ,thiscauseMobileIPv6toincurlongdelayintheregis tration process,andaddsignalingtraffictothebackbonenetworkespeciallywhentheHAandCNarefarawayfromtheMN .Inordertominimizethisdelay ,andthesignalingoverhead presentinMobileIPv6,literatures[4～7] proposeHierarchicalMobileIPv6(HMIPv6)architectureandafasthan dover…     

Dynamic SDN controller placement based on latency in LEO satellite network

In view of the problem of large network latency when the controller synchronized information to maintain the global network view,the latency-based SDN controller on-demand placement scheme was proposed.Firstly,the satellite subnet division method based on redundant coverage was designed according to the relative velocity of satellite and terminal.Then,the controller placement model was established by analyzing the response latency of the satellite distributed control.Finally,the controller placement problem was transformed into the soft capacitated facility location problem,and the approximation algorithm was designed to solve the model.The experimental results show that the proposed scheme can optimize network latency while meeting networking coverage demands.     

Markov prediction based handover in dynamic ultra dense network

In order to solve the problem of the communication and computational problems of large-scale machine communication in an ultra-dense cellular network,a Markov prediction based handover scheme (MPHS) was proposed.Firstly,a kind of heterogeneous network design with semi-structure and central control was considered which contains the densely deployed virtual nodes and thus realized a low cost and efficient coverage.The network can dynamically adjust the access point according to the user's mobility and network traffic.Secondly,a Markov model was constructed,and the idea of load-aware was introduced.By weighing the signal quality and the cell load,the user's next optimal access point was effectively predicted.The simulation results show the feasibility and effectiveness of the proposed scheme for cell handover predicting.     

Energy‐efficient network selection with mobility pattern awareness in an integrated WiMAX and WiFi network

To provide wireless Internet access, WiFi networks have been deployed in many regions such as buildings and campuses. However, WiFi networks are still insufficient to support ubiquitous wireless service due to their narrow coverage. One possibility to resolve this deficiency is to integrate WiFi networks with the wide‐range WiMAX networks. Under such an integrated WiMAX and WiFi network, how to conduct energy‐efficient handovers is a critical issue. In this paper, we propose a handover scheme with geographic mobility awareness (HGMA), which considers the historical handover patterns of mobile devices. HGMA can conserve the energy of handovering devices from three aspects. First, it prevents mobile devices from triggering unnecessary handovers according to their received signal strength and moving speeds. Second, it contains a handover candidate selection method for mobile devices to intelligently select a subset of WiFi access points or WiMAX relay stations to be scanned. Therefore, mobile devices can reduce their network scanning and thus save their energy. Third, HGMA prefers mobile devices staying in their original WiMAX or WiFi networks. This can prevent mobile devices from consuming too much energy on interface switching. In addition, HGMA prefers the low‐tier WiFi network over the WiMAX network and guarantees the bandwidth requirements of handovering devices. Simulation results show that HGMA can save about 59– 80% of energy consumption of a handover operation, make mobile devices to associate with WiFi networks with 16–62% more probabilities, and increase about 20–61% of QoS satisfaction ratio to handovering devices. Copyright © 2009 John Wiley & Sons, Ltd.     

SEAL2: An SDN‐enabled all‐Layer2 packet forwarding network architecture for multitenant datacenter networks

This paper presents the design and development of a new network virtualization scheme to support multitenant datacenter networking (MT‐DCN) based on software‐defined networking (SDN) technologies. Effective multitenancy supports are essential and challenging for datacenter networking designs. In this study, we propose a new network virtualization architecture framework for efficient packet forwarding in MT‐DCN. Traditionally, an internet host uses IP addresses for both host identification and location information, which causes mobile IP problems whenever the host is moved from one IP subnet to another. Unfortunately, virtual machine (VM) mobility is inevitable for cloud computing in datacenters for reasons such as server consolidation and network traffic flow optimization. To solve the problems, we decouple VM identification and location information with two independent values neither by IP addresses. We redefine the semantics of Ethernet MAC address to embed tenant ID information to the MAC address field without violating its original functionality. We also replace traditional Layer2/Layer3 two‐stage routing schemes (MAC/IP) with an all‐Layer2 packet forwarding mechanism that combines MAC addresses (for VM identification and forwarding in local server groups under an edge switch gateway) and multiprotocol label switching (MPLS) labels (for packet transportation between edge switch gateways across the core label switching network connecting all the edge gateways). To accommodate conventional IP packet architecture in a multitenant environment, SDN (OpenFlow) technology is used to handle all this complex network traffics. We verified the design concepts by a simple system prototype in which all the major system components were implemented. Based on the prototype system, we evaluated packet forwarding efficiency under the proposed network architecture and compared it with conventional IP subnet routing approaches. We also evaluated the incurred packet processing overhead caused by each of the packet routing components.     

新一代互联网移动管理机制研究

 传统互联网以"固定、有线"为主的连通方式,难以适应新的无线/移动网络的发展需求.本文提出了一种新一代互联网移动管理机制——标识分离映射机制ISMS,详细介绍了ISMS的基本理论和协议流程,并与移动IPv6协议进行了性能分析和对比.ISMS是一种基于网络的移动管理机制,其切换管理和位置管理均由网络完成,能够满足新一代互联网移动管理机制在快速切换、路由优化、可扩展、可控可管、保护位置隐私、安全性和降低无线链路开销等方面的需求.理论分析表明ISMS的网络层面平均切换时延远小于移动IPv6的平均切换时延,能够有效支持绝大部分实时应用.原型系统的实现和验证进一步说明了ISMS的可行性和有效性.     

Performance analysis of an advanced heterogeneous mobile network architecture with multiple small cell layers

The integration of small cell technologies into the current mobile network operators is a necessity for providing capacity and coverage improvement in the future mobile networks (5G). This integration paves the way for heterogeneous networking. In this paper, a novel heterogeneous architecture for the efficient integration of small cell technology into the current mobile networks is developed, namely advanced heterogeneous mobile network (AHMN). AHMN architecture consists of a stack of multiple cell layers wherein the upper layer is the macrocell layer while under this layer, a number of lower small cell layers are formed. Focusing on femtocells and metrocells, as the most typical paradigms of small cells, a femtocell layer which serves the indoor traffic activity of femtocell users is considered, while the metrocell serves the outdoor traffic activities as well as the overflow traffic from femtocells. The overall heterogeneous network (HetNet) is completed with the macrocell overlay layer, which serves only the macrocell users and the overflowed traffic from the underlay metrocell layer. In the proposed AHMN architecture, the metrocell layer is deployed as a complementary layer between the macrocell and femtocell layers and facilitates the handover traffic interaction between the edge layers. Meanwhile, the mobility management in this architecture is critical and hence, the interaction between successive network layers, due to the handover (HO) traffic, is analyzed. Furthermore, for each network layer, a guard channel scheme is proposed in order to minimize the HO dropping rate of the mobile users. We show both analytically and by simulation the capability of AHMN in offloading traffic and reducing the blocking/dropping probability compared with the traditional macrocellular network.     

SMS-MIPv6: An End-to-End Mechanism for IPv6 Mobility Management in Mobile Networks

As IP has been extended from core networks to access networks, a mobile network can be considered as an overlay of a traditional cellular network and an IP network. SMS-MIPv6 attempts to integrate mobility management of these two kinds of networks. The basic idea behind SMS-MIPv6 is to exploit existing mobility management in the cellular network (i.e. in the form of well-defined short messages) to locate a Mobile Terminal (MT) in the IPv6 network. We should emphasize that the motivation of SMS-MIPv6 is not to replace or optimize existing mature mobility management schemes. On the contrary, as an entirely end-to-end mechanism for IPv6 mobility management, it provides an alternative mechanism for free peer-to-peer applications such as Voice over IP (VoIP) without support from mobile network operators. We describe the implementation of SMS-MIPv6 in detail and analyze its performance. The evaluation results show that SMS-MIPv6 achieves acceptable performance so that it can be deployed in most current mobile networks. It performs best in terms of signaling cost, data traffic overhead compared with Mobile IPv6 (MIPv6) and Proxy MIPv6 (PMIPv6). Moreover, SMS-MIPv6 can reduce the handover latency significantly, although it is considered as a mobility management scheme for global mobility. However, it increases the session initialization latency due to hybrid binding through the cellular network.     

A Comprehensive Framework for Evaluating IPv6 Based Mobility Management Protocols

Seamless mobility in future generation networks, which are envisioned to be heterogeneous in nature, is an important issue. While Internet Engineering Task Force (IETF) work groups have standardized various mobility management protocols, such as Mobile IPv6 and Proxy Mobile IPv6, a comprehensive study of these protocols in terms of various performance characteristics is a challenging issue. Moreover, this study also considers the recent proposals from IETF in distributed mobility management (DMM) protocols. In this paper, a novel analytical model is developed for comparison of various mobility management protocols in terms of handover latency, as well as packet density, and packet arrival rate during the handover time by applying transport engineering principles in the field of telecommunication. The signaling cost analysis using signaling overhead incurred during protocol operations is given for each of these protocols. The number of packets that can be lost during the handover operation is also obtained using this model. Moreover, it presents a unified framework using which one can assess the performance characteristics of both host based and network based mobile IP protocols. One can also assess the performance of centralized and DMM approaches. The correctness of the proposed model is established by the fact that it leads to results similar to those obtained by applying some of the existing models. At the same time, the model allows one to obtain additional results showing the effect of packet density and packet arrival rate on the handover latency.     

Hierarchical mobile network binding scheme for route optimization in NEMO

Recently, there has been a great deal of research on network mobility management that can support the movement of a mobile network consisting of several mobile nodes. The IETF NEMO working group proposed a basic support protocol, which defines methodology for supporting network mobility by using bi-directional tunneling between the home agent and the mobile router. This protocol, however, suffers from the ‘pinball routing problem,’ and most of the research attempts to solve this problem still have limitations in the efficiency of intra-domain communication. Moreover, these methods require additional binding procedures in case of the root mobile router handover. In this paper, we propose new route optimization methodology that can remedy these limitations by using asymmetric tunneling and a hierarchical local binding mechanism, which can provide faster signaling and data transmission. It can also be easily extended to support micro-mobility without the need for additional extensions. The performance is evaluated by simulation which can show the efficiency of the approach, compared with several previous route optimization methods.     

基于移动代理的SNMP网络管理体系研究

和传统的固定代理相比，移动代理可自主地在网络设备中迁移并进行本地数据采集和计算，这简化了网络管理者同代理之间的通信过程，降低了网管数据流量，减少了网管反应时间。首先，提出基于移动代理的SNMP网络管理体系的结构及实现，其次对比分析了传统SNMP网管的轮询和基于移动代理网管的串行、并行的访问方式，最后通过实验对上述三种方式的性能进行测试。实验结果表明，和传统固定代理相比，采用移动代理的网络管理体系能显著提高网络管理的效能。     

Vehicular HetNet load distribution using centralized control of software‐defined network

Current vehicular communication systems experience from nonflexible and costly devices, complicated control‐plane protocols, and vendor‐specific configuration interfaces. In the next generation vehicular communication, a mobile device (MD) will be installed on a car capable of accessing multiple services from different networks. So heterogeneous networks (HetNets) may play a vital role in vehicular communication. Despite heterogeneity, flawless connectivity between different systems is a basic need of the travellers. The key challenge for seamless connectivity is the design of a vertical handover (VHO) scheme. We claim that software‐defined networking (SDN) can make things easier in the design and supervision of VHO in vehicular HetNet. The proposed method maximizes the HetNet utilization with lesser handover by balancing the load among the HetNets. Simulation results performed in MATLAB justified that this novel architecture with proper VHO technique boosts the performance by balancing the load, reducing unnecessary VHO, etc. Performance is analyzed by considering four studies, ie, handover served ratio (HSR), on board units (OBUs), OBU served ratio (OSR), and total throughput and total capacities of road side units (RSUs) to serve handover demands from OBUs. It is observed that the HSR increases rapidly as the number of OBUs increases, which indicates almost all the handover requested OBUs are allocated resources by a connected RSU. We also studied the served total throughput by considering VHO with SDN, without SDN in the average case and without SDN in the best case, and it is observed that with SDN as a central controller, the total OSR and total throughput is increased.     

Mobility management approaches for SDN-enabled mobile networks

The evolving network technologies aim at meeting the envisioned communication demands of future smart cities and applications. Although software-defined networking (SDN) enables flexible network control, its applicability to mobile networks is still in its infancy. When it comes to introducing the SDN vision to mobile networks, handling of wireless events and mobility management operations stand out as major challenges. In this paper, we study the scalability issues of SDNized wireless networks, specifically those relevant to mobility management. We design and implement different mobility management approaches in SDNized wireless networks and investigate the impact of various system variables on the overall handover delays. We also study the improvements in handover delays: (i) when a proposed proactive mobility management algorithm is implemented; (ii) when the controller delegates partial control of mobility management to the forwarding entities. For the implementation of the proposed approaches on the OpenFlow network, the paper also suggests potential extensions to the OpenFlow protocol. The contributed approaches are validated on a full-scale demonstrator, with results showing that proactive outperforms reactive and that the delegated control approach performs better than proactive for smaller topology sizes. Furthermore, a proposal for LTE X2-specific control delegation is discussed as a use case.