Signaling cost and performance of SIGMA: A seamless handover scheme for data networks

Mobile IP has been developed to handle mobility of Internet hosts at the network layer. Mobile IP (MIP), however, suffers from a number of drawbacks such as requirement of infrastructure change, high handover latency, high packet loss rate, and conflict with network security solutions. In this paper, we describe and evaluate the performance of SIGMA, a Seamless IP diversity‐based Generalized Mobility Architecture. SIGMA utilizes multihoming to achieve seamless handover of mobile hosts, and is designed to solve many of the drawbacks of MIP, including requirement for changes in infrastructure. We first evaluate the signaling cost of SIGMA and compare with that of hierarchical Mobile IPv6 (an enhancement of Mobile IP) by analytical modeling, followed by comparison of handover performance of SIGMA and Mobile IPv6 enhancements. Criteria for performance evaluation include handover latency, packet loss, throughput, and network friendliness. Our results indicate that in most cases SIGMA has a lower signaling cost than Hierarchical Mobile IPv6. Moreover, for a typical network configuration, SIGMA has a higher handover performance over Mobile IP. Copyright © 2005 John Wiley & Sons, Ltd.     

A Robust Seamless Handover Scheme for the Support of Multimedia Services in Heterogeneous Emerging Wireless Networks

With the rapid development of wireless technologies and numerous types of mobile devices, the need to support seamless multimedia services in Mobile and Ubiquitous Computing (MUC) is growing. To support the seamless handover, several mobility protocols such as Mobile IPv6 (MIPv6) (Johnson et al., Mobility Support in IPv6, IETF, RFC 3775, 2004) and fast handover for the MIPv6 (FMIPv6) (Koodli et al. Past handovers for mobile IPv6 (FMIPv6), IETF, RFC 4068, 2005) were developed. However, MIPv6 depreciates the Quality-of-Service (QoS) especially in multimedia service applications because of the long handover latency and packet loss problem. To solve these problems in the MIPv6, FMIPv6 is proposed in the Internet Engineering Task Force (IETF). However, FMIPv6 is not robust for the multimedia services in heterogeneous emerging wireless networks when the MN may move to another visited network in contrast with its anticipation. In MUC, the possibility of service failure is more increased because mobile users can frequently change the access networks according to their mobility in heterogeneous wireless access networks such as 3Generation (3G), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMax) and Bluetooth co-existed. In this paper, we propose a robust seamless handover scheme for the multimedia services in heterogeneous emerging wireless networks. The proposed scheme reduces the handover latency and handover initiation time when handover may fail through the management of tentative Care-of Addresses (CoAs) that does not require Duplicate Address Detection (DAD). Through performance evaluation, we show that our scheme provides more robust handover mechanism than other scheme such as FMIPv6 for the multimedia services in heterogeneous emerging wireless networks.     

Fast RSVP: Efficient RSVP Mobility Support for Mobile IPv6

In recent years, with the development of mobile communication technologies and the increase of available wireless transmission bandwidth, deploying multimedia services in next generation mobile IPv6 networks has become an inevitable trend. RSVP (resource reservation protocol) proposed by the IETF is designed for hardwired and fixed networks and can not be used in mobile environments. This paper proposes a protocol, called Fast RSVP, to reserve resources for mobile IPv6. The protocol adopts a cross-layer design approach where two modules (RSVP module and Mobile IPv6 module) at different layers cooperate with each other. Fast RSVP divides a handover process with QoS guarantees into two stages: (1) setup of the resource reservation neighbor tunnel and (2) resource reservation on the optimized route. It can help a mobile node realize fast handover with QoS guarantees as well as avoid resource wasting by triangular routes, advanced reservations and duplicate reservations. In addition, fast RSVP reserves “guard channels” for handover sessions, thus greatly reducing the handover session forced termination rate while maintaining high performance of the network. Based on extensive performance analysis and simulations, Fast RSVP, compared with existing methods of resource reservation in mobile environments, performs better in terms of packet delay and throughput during handover, QoS recovery time after handover, resource reservation cost, handover session forced termination rate and overall session completion rate.     

An adaptive hierarchical mobile IPv6 using mobility profile

The Hierarchical Mobile IPv6 (HMIPv6), which is based on the Mobile IPv6 (MIPv6), has been proposed by IETF to reduce registration control signaling. It separates micro‐mobility from macro‐mobility with the help of an intermediate mobility agent, called the mobility anchor point (MAP), and exploits a Mobile Node's (MN's) spatial locality. However, all packets from a Correspondent Node (CN) to an MN are delivered through the MAP. That causes delay in packets delivery and the congestion of packets in the MAP so that it results in deterioration of network capability. To alleviate these problems, we propose a Hierarchical Mobile IPv6 protocol using not only spatial locality but also temporal locality. We introduce a profile for management of these locality information. According to the information in the profile, some packets are directly delivered to an MN, if MN seems to reside for a long time in the current subnet. Also, we introduce a handover scheme with the help of an L2 trigger, so that the proposed scheme takes nearly the same handover delay time as HMIPv6. The other contribution of this paper is to suggest a mathematical modeling and analysis of network traffic costs, MAP processing costs and handover latency for both HMIPv6 and the proposed scheme. Copyright © 2004 John Wiley & Sons, Ltd.     

The Performance Analysis of the Multicast Extension Support for Proxy MIPv6

Mobile multicast is based on the traditional multicast protocols and the mobility support protocols to provide the multicast services for the mobile subscribers. Several mobile multicast methods were proposed in the past few years, but most of them are based on Mobile IPv6 and its variants which require the mobile node to support the mobility function. Recently, Proxy Mobile IPv6 (PMIPv6) was proposed to provide the mobility support for the mobile node with or without mobility function, and the previous studies have shown that PMIPv6 can improve the performance in term of the handover performance and protocol cost. However, PMIPv6 mainly concerns on the mobility support for unicast routing and little considers the multicast routing. In this paper, we propose two multicast methods called the MAG (Mobile Access Gateway)-based method and LMA (Local Mobility Anchor)-based method based on the different multicast delivery transmission path to extend PMIPv6, and analyze their performance under the different scenarios. The analytical results show that the LMA-based method is suitable for the higher speed, bigger domain size, and larger network topology scenarios, whereas the MAG-based method is suitable for the lower speed, smaller domain size and smaller network topology scenarios.     

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.     

LR-AKE-Based AAA for Network Mobility (NEMO) Over Wireless Links

Network mobility introduces far more complexity than host mobility. Therefore, host mobility protocols such as Mobile IPv6 (MIPv6) need to be extended to support this new type of mobility. To address the extensions needed for network mobility, the IETF NEMO working group has recently standardized the network mobility basic support protocol in RFC 3963. However, in this RFC, it is not mentioned how authentication authorization and accounting (AAA) issues are handled in NEMO environment. Also, the use of IPsec to secure NEMO procedures does not provide robustness against leakage of stored secrets. To address this security issue and to achieve AAA with mobility, we propose new handover procedures to be performed by mobile routers and by visiting mobile nodes. This new handover procedure is based on leakage resilient-authenticated key establishment (LR-AKE) protocol. Using analytical models, we evaluate the proposed handover procedure in terms of handover delay which affects the session continuity. Our performance evaluation is based on transmission, queueing and encryption delays over wireless links.     

Performance Analysis of Hierarchical Mobile IPv6: Does it Improve Mobile IPv6 in Terms of Handover Speed?

There has been a rapid growth in the need to support mobile nodes in IPv6-based networks. IETF has completed to standardize Mobile IPv6 (MIPv6) and Hierarchical Mobile IPv6 (HMIPv6) for supporting IPv6 mobility. Even though existing literatures have asserted that HMIPv6 generally improves MIPv6 in terms of handover speed, they do not carefully consider the details of the whole handover procedures. In this paper, based on the current IETF standards of both MIPv6 and HMIPv6, we conduct a comprehensive study of all IP-level handover procedures: movement detection, duplicate address detection, and location registration. Based on this study, we provide a mathematical analysis on MIPv6 and HMIPv6 performance in terms of handover speed. From the analysis, we reveal that the average HMIPv6 handover latency is not always lower than the average MIPv6 handover latency. Furthermore, even the intra-domain handover latency of HMIPv6 is not reduced much compared with MIPv6 handover latency. A finding of our analysis is that optimization techniques for movement detection and duplicate address detection are essential to shortening HMIPv6 handover latency and increasing the benefit of HMIPv6.

基于特征投影的移动IPv6快速切换方法

研究了移动IPv6协议中的越区切换问题,提出了一种基于特征投影的移动IPv6快速切换方法。该方法通过构造先验切换经验与小区覆盖范围的映射关系来协助移动接入网关对切换目的地进行预测。仿真结果表明,文中方法能够获得比FPMIPv6更小的切换延迟,并具有较好的鲁棒性。     

Load balancing and its performance evaluation for layer 3 and IEEE 802.21 frameworks in PMIPv6‐based wireless networks

Mobile IP (MIP) requires mobile nodes (MNs) to register with the home agents (HAs) whenever the MNs change their point of attachment (PoA: access point (AP) or base station (BS)) in different subnets. Thus, such registrations cause excessive signaling overhead and long service delay. To solve this problem, proxy mobile IPv6 (PMIPv6) has been proposed by the IETF NETLMM working group. In PMIPv6, a new entity called mobile access gateway (MAG) performs the mobility‐related signaling with the local mobility anchor (LMA) on behalf of the MN and establishes a tunnel with the LMA. However, a number of MNs must be associated with an MAG, which means that the MAG can be easily overloaded. Therefore, in this paper, we propose a load balancing mechanism among the MAGs in the PMIPv6 network. The PMIPv6 handover signaling procedure is extended to support the proposed load balancing mechanism. We also discuss using IEEE 802.21 Media Independent Handover (MIH) protocol for load balancing to determine the load status at the candidate PoAs, in addition to the load status at the candidate MAGs. To evaluate the performance, we analyze the average waiting time in the queue at the MAG. Through simulations and numerical analysis, we show that the proposed load balancing mechanism can produce less queueing delay at the MAG and a higher data transmission rate at the PoA than when a load balancing operation is not performed in the PMIPv6 network. Copyright © 2009 John Wiley & Sons, Ltd.     

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.     

Predictive versus Reactive—Analysis of Handover Performance and Its Implications on IPv6 and Multicast Mobility

Handovers in mobile packet networks commonly produce packet loss, delay and jitter, thereby significantly degrading network performance. Mobile IPv6 handover performance is strongly topology dependent and results in inferior service quality in wide area scenarios. To approach seamless mobility in IPv6 networks predictive, reactive and proxy schemes have been proposed for improvement. In this article we analyse and compare handover performance and frequencies for the corresponding protocols, as they are an immediate measure on service quality. Using analytical methods as well as stochastic simulations, we calculate the performance decreases originating from different handover schemes, the expected number of handovers as functions of mobility and proxy ratios, as well as the mean correctness of predictions. In detail we treat the more delicate case of these rates in mobile multicast communication. It is obtained that performance benefits, expected from simple analysis of predictive schemes, do not hold in practice. Reactive and predictive handovers rather admit comparable performance. Hierarchical proxy environments—foremost in regions of high mobility—can significantly reduce the processing of inter–network changes. Reliability of handover predictions is found on average at about 50%.     

DMAP: integrated mobility and service management in mobile IPv6 systems

Mobile IPv6 (MIPv6) is a work in progress IETF standard for enabling mobility in IPv6 networks and is expected to have wide deployment. We investigate an integrated mobility and service management scheme based on MIPv6 with the goal to minimize the overall network signaling cost in MIPv6 systems for serving mobility and service management related operations. Our design extends IETF work-in-progress Hierarchical Mobile IPv6 (HMIPv6) with the notion of dynamic mobility anchor points (DMAPs) for each mobile node (MN) instead of static ones for all MNs. These DMAPs are access routers chosen by individual MNs to act as a regional router to reduce the signaling overhead for intra-regional movements. The DMAP domain size, i.e., the number of subnets covered by a DMAP, is based on the MN’s mobility and service characteristics. Under our DMAP protocol, a MN interacts with its home agent and application servers as in the MIPv6 protocol, but optimally determines when and where to launch a DMAP to minimize the network cost in serving the user’s mobility and service management operations. We demonstrate that our DMAP protocol for integrated mobility and service management yields significantly improved performance over basic MIPv6 and HMIPv6.     

A Novel SIP-Based Route Optimization for Network Mobility

With the provision of various wireless services, e.g., third-generation (3G) and wireless local area network (WLAN), more and more people request to access the Internet anywhere at anytime. For example, people want to check their e-mails on the bus or watch online news while traveling in the train. For this purpose, the Internet Engineering Task Force (IETF) proposed the concept of network mobility, i.e., a set of users move as a unit. We motivate the network mobility problem by considering the state-of-the-art scenario of the network mobility (NEMO) basic support protocol that is extended from the Mobile IPv6 (MIPv6). In order to avoid the same problems suffered by MIPv6, a new session initiation protocol (SIP)-based network mobility management scheme called SIP-NEMO is designed and proposed in this paper. The proposed SIP-NEMO not only copes with the movement of a mobile network but also achieves the route optimization between two SIP clients without too many signaling messages over wireless links, even if the mobile network is nested. In this paper, we also analytically compute and simulate the performance of SIP-NEMO with the NEMO basic support protocol proposed by the IETF.     

Analysis and Evaluation of Mobile IPv6 Handovers over Wireless LAN

In this paper, we analyze the IPv6 handover over wireless LANs. Mobile IPv6 is designed to manage mobile nodes movements between wireless IPv6 networks. Nevertheless, a mobile node cannot receive IP packets on its new point of attachment until the handover completes. Therefore, a number of extensions to Mobile IPv6 have been proposed to reduce the handover latency and the number of lost packets. We focus on Fast Mobile IPv6 which is an extension of Mobile IPv6 that allows the use of L2 triggers to anticipate the handover. We compare the handover latency in four specific cases: basic Mobile IPv6, the forwarding method of Mobile IPv6, the Anticipated method, and the Tunnel-Based Handover. The results of the handover latency are calculated with the L2 properties of IEEE 802.11b. In particular, we take into account the L2 handover for different configurations of the wireless network.     

Seamless handover support over heterogeneous networks using FMIPv6 with definitive L2 triggers

Various wireless communication systems have been developed and will be integrated into an IP-based network to offer end users the Internet access anytime and anywhere. In heterogeneous multi-access networks, one of main issues is to manage nodes’ mobility with session continuity and minimal handover latency. In order to support the mobility of mobile nodes, MIPv6 has been proposed by IETF. Even though MIPv6 provides a solution to handling nodes’ mobility in IPv6 networks, there is a significant problem due to its inability to support a seamless handover caused by long latency and high packet losses during a handover. FMIPv6 has been proposed to reduce MIPv6 handover latency by using an address pre- configuration method with the aid of L2 triggers. Current research defines a general L2 trigger model for seamless handover operation, but it does not address the exact timing and definitive criteria of L2 triggers which causes a significant effect on the handover performance of FMIPv6. This paper considers the available timing and accurate criteria of L2 triggers. With the definitive L2 triggers, we present a practical handover scenario to integrate L2 and L3 layers for low handover latency and low number of packet losses during a handover. We also study the impact of definitive L2 triggers on the handover performance of the FMIPv6 protocol in real testbeds and prove that the FMIPv6 protocol performs its handover operation prior to the L2 handover and obtains a seamless handover.     

Tunnel Restraint to Prevent Out-of-Order Packets for Route Optimization in Proxy Mobile IPv6

Route optimization (RO) developed for Proxy Mobile IPv6 (PMIPv6) aims at reducing the packet transmission cost. However, as we present in this paper, the RO procedure may cause out-of-order packets. In this paper, we propose a tunnel restraint scheme to minimize out-of-order packets during a mobile node (MN)’s handover by utilizing a developed estimation function that calculates an amount of out-of-order packets in the RO procedure. In the proposed tunnel restraint scheme, buffering techniques at proxy mobility agents are adopted to minimize the arrival of out-of-order packets to the MN. The proxy mobility agents taking part in the RO procedure buffer the packets for the MN until they establish the RO tunnel between them. The conducted performance evaluation results show that the traffic rate and the time period of out-of-order packets mainly have effects on the out-of-order packets problem. We also demonstrate that the proposed tunnel restraint scheme enhances the performance of PMIPv6 RO by minimizing the number of out-of-order packets.     

Improving Mobile IPv6 handover and authentication in wireless network with E‐HCF

Mobile IP allows a mobile node to maintain a continuous connectivity to the Internet when moving from one access point to another. However, due to the link switching delay and to Mobile IP handover operations, packets designated to mobile nodes can be delayed or lost during the handover period. Moreover, every time a new attach point is confirmed, the mobile node, its home agent and its corresponding node must be authenticated mutually. This paper presents a new control function called Extended Handover Control Function (E‐HCF) in order to improve handover performance and authentication in the context of Mobile IPv6 over wireless networks. With an analytical model and some OPNET simulations, we show in this paper that our solution allows provision of low latency, low packet loss and mutual authentication to the standard handover of Mobile IPv6. Copyright © 2009 John Wiley & Sons, Ltd.     

Hierarchical mobility management for fast handoff and load distribution in IPv6 networks

Hierarchical Mobile IPv6 (HMIPv6) has been proposed by the Internet engineering task force (IETF) to compensate for such problems as handover latency and signalling overhead when employing Mobile IPv6 (MIPv6). HMIPv6 supports micro‐mobility within a domain and introduces a new entity, namely mobility anchor point (MAP) as a local home agent (HA). However, HMIPv6 has caused load concentration at a particular MAP and longer handover latency when an inter‐domain handover occurs. In order to solve such problems, this paper establishes a virtual domain (VD) of a higher layer MAP and proposes a MAP changing scheme. The MAP changing scheme enables complete handover by using binding‐update of the on‐link care of address (LCoA) only when inter‐domain handover occurs. In addition, the concentrated load of a particular MAP is distributed as well. Copyright © 2008 John Wiley & Sons, Ltd.     

Handover management for mobile nodes in IPv6 networks

We analyze IPv6 handover over wireless LAN. Mobile IPv6 is designed to manage mobile nodes' movements between wireless IPv6 networks. Nevertheless, the active communications of a mobile node are interrupted until the handover completes. Therefore, several extensions to Mobile IPv6 have been proposed to reduce the handover latency and the number of lost packets. We describe two of them, hierarchical Mobile IPv6, which manages local movements into a domain, and fast handover protocol, which allows the use of layer 2 triggers to anticipate the handover. We expose the specific handover algorithms proposed by all these methods. We also evaluate the handover latency over IEEE 802.11b wireless LAN. We compare the layer 2 and layer 3 handover latency in the Mobile IPv6 case in order to show the saving of time expected by using anticipation. We conclude by showing how to adapt the IEEE 802.11b control frames to set up such anticipation.