A Fast Handover Control Scheme Using the Optimistic Ready-Tunneling (ORT) Approach

Fast handover protocol provides seamless handover in mobile IPv6 networks by reducing handover latency. One assumption in fast handover is that the MN (Mobile Node) or the network could know or predict the new AR (Access Router) before data transport from the previous AR to the MN is disrupted. In order to achieve this capability, the complexity of predicting the new AR and the diversity of the wireless link technologies should be considered. While it is difficult to know or predict the new AR exactly, a better solution is required to find a reasonable set of candidate ARs (i.e., neighbor ARs) that are likely to be the new AR after a handover. This paper introduces a solution to support a fast handover mechanism using multi-tunnels between MAP (Mobility Anchor Point) and neighbor ARs in HMIPv6 (Hierarchical Mobile IPv6) network. It includes the concepts of Proxy Mobile IP for creation of CoA (Care of Address) and DAD (Duplicate Address Detection). In this protocol, the MN can handover without receiving any information about the new AR and this eliminates difficulties to know or predict exactly the new AR which is not specified in standard fast handover scheme. It decouples layer-2 and layer-3 handover and efficiently reduces handover latency through the minimized number of wireless signaling messages and pre-DAD. It also saves periods of service disruption and prevents packet loss in the case of ping-pong movement of the high-speed MN. The performance of the proposed mechanism is evaluated by simulations under variable conditions.

To maintain the Internet connectivity of a group of nodes in intelligent transportation systems (ITSs), the network mobility basic support (NEMO BS) protocol was standardized. The NEMO BS provides mobility for mobile network nodes (MNNs) in a moving network through a mobile router (MR). Since packet loss in NEMO dramatically increases during a handover as the number of MNNs increases, Mobile IPv6 fast handovers (FMIPv6) was adopted to reduce packet loss and handover latency. However, since FMIPv6 was originally designed for a single mobile node (MN), FMIPv6 based on NEMO (fNEMO) incurs a high tunneling burden on the link between the previous and new access routers (PAR and NAR, respectively). In this paper, we propose an enhanced fNEMO (EfNEMO) as an efficient fast handover scheme that significantly mitigates the tunneling burden and handover latency. In particular, EfNEMO performs a tentative binding update (BU) procedure to register a new care-of address (NCoA) for the MR with the MR's home agent (HA) before the layer-2 handover. Consequently, EfNEMO delivers packets destined for MNNs via various paths between the HA and the NAR without any tunneling. Furthermore, EfNEMO reduces handover latency because it performs the registration to the HA in advance. By establishing an analytical model for the proposed EfNEMO, we investigate the handover performance of NEMO, fNEMO, and EfNEMO. In addition, we compare EfNEMO with NEMO and fNEMO in terms of the overall cost and the handover latency. Simulation is also performed to compare in a more realistic environment. The results of analysis and simulation show that EfNEMO significantly outperforms fNEMO and NEMO.

Network Mobility (NEMO), derived from Mobile Internet Protocol version 6 (MIPv6) technology, has been evolving and expanding in very rapidity manner across very short period of time. In MIPv6 technology, the Access Router (AR) plays important roles such as provide sessions connectivity and safe-guarding communications protocol. Whereas in NEMO, the routers in the communication chains are essentially the moving targets and hence the Mobile Router (MR). The MR too, inherits the basic functionalities of AR. In the basic MIPv6 and NEMO modus operandi, when the Mobile Network Notes (MNN) roamed away from home link and attached to some other foreign link, the MNNs are also addressable via a secondary address named as Care-of Address (CoA). The MNN essentially registered its primary CoA to the router on its own home link and thus registering the router to be its Home Agent (HA). These communication sets, and the ingredients of the communication will be managed via Binding Updates (BU) and the Binding Acknowledgement (BAck). Since the NEMO is using MIPv6 as the backbone, NEMO also inevitably inherits many design difficulties and problems that the MIPv6 seen. Such as using the Internet Protocol Security (IPSec) with end-to-end tunneling and using nonce value within the BU to serve as part of the authentication process and many more. In this paper, we illustrate the scenario of authentication problems involving NEMO movements and the flaw in security design. With the aim of succeeding IPSec we then propose a much better solution which is the use of Random Number, coupled with PKI concept.

The main goal of mobile IPv6 is that a mobile node is always addressable by its home address, whether it is currently attached to its home link or is away from home. Mobile IPv6 enables applications running on an Internet node to survive physical reconnection by inserting a few additional features at the network layer. In this paper, focus is given to a micro-mobility based test-bed development with improved algorithm. The test-bed consists of both hardware and software, including four PCs and one laptop. The laptop is used as mobile host (MH), two PCs act as access points, one PC becomes the home agent (HA) and one PC is used as a multicast router (ML). This test-bed is used to verify the theoretical enhancement of the micro-mobility handover algorithm via the results (packet loss, handover delay and quality of service). There is no signaling traffic overload between the MH, HA and correspondent host (CH), the handover delay is low, approximately below 10 ms, and the video stream has good reception.

An enhanced fast handover with seamless mobility support for next-generation wireless networks

Delay and packet loss caused by the basic mobile IPv6 handover protocol can not guarantee the service quality of real-time communication. In order to improve the performance of fast handover of the mobile IPv6, we proposed a fast handover scheme based on hierarchical mobility which combines micro mobility and the link layer trigger. By shielding local mobility of the mobile node, the scheme can greatly reduce the signaling information traffic from mobile node to HA and CN. Through the link layer trigger mechanism, the scheme builds a tunnel in advance to avoid packet loss. In order to verify the performance of the proposed scheme, we did some simulation experiments in the NS-2 environment. The simulation results show that the scheme reduces handover delay and packet loss effectively.

The ongoing convergence of wireless networking and IP networking more and more requires solutions for transporting realtime application data to IP enabled mobile devices and mobile networks. Even though the basic Mobile IPv6 protocol suite performs sufficient in macro environments with non realtime traffic, seamless mobility requires some more enhanced protocol procedures in between the mobile node and the involved network entities.Limiting the effect of handovers has the potential to considerably improve handover performance in terms of latency, packet loss, signaling overhead, and scalability. This contribution is going to present an extensive simulation study on the performance of the Fast Handovers for Mobile IPv6 approach. The demonstrated simulation scenario comprises 9 access router and up to 70 Mobile Nodes that communicate in accordance with the popular IEEE 802.11 wireless LAN standard.

The miniaturization of the computing machinery increases needs for using mobile computing of users. In this situation, Mobile IPv6 Working Group of Internet Engineering Task Force (IETF) suggests IPSec for Mobile IPv6 security. IPSec, however, has a long latency problem of dynamic security authentication due to the key management and a large amount of calculation. We therefore apply AAA in Mobile IPv6 to solve a dynamic security authentication problem of IPSec and simultaneously use Fast Handover technique for quick mobility. And we propose a method for reducing a long latency caused by authentication of mobile node (MN) during a handover. Old and new access routers authenticated by a hash value of an MN are able to reuse existing Security Authentication (SA) for a certain time and reduce latency for new SA. As a consequence, a mobile node can provide the real time services due to the reduction of authentication latency. Also, we can trust the buffered information through the tunnel between two access routers.

Due to the proliferation of handheld mobile devices, multimedia applications like Voice over IP (VoIP), video conferencing, network music, and online gaming are gaining popularity in recent years. These applications are well known to be delay sensitive and resource demanding. The mobility of mobile devices, running these applications, across different networks causes delay and service disruption. Mobile IPv6 was proposed to provide mobility support to IPv6-based mobile nodes for continuous communication when they roam across different networks. However, the Route Optimization procedure in Mobile IPv6 involves the verification of mobile node's reachability at the home address and at the care-of address (home test and care-of test) that results in higher handover delays and signalling overhead. This paper presents an enhanced procedure, time-based one-time password Route Optimization (TOTP-RO), for Mobile IPv6 Route Optimization that uses the concepts of shared secret Token, time based one-time password (TOTP) along with verification of the mobile node via direct communication and maintaining the status of correspondent node's compatibility. The TOTP-RO was implemented in network simulator (NS-2) and an analytical analysis was also made. Analysis showed that TOTP-RO has lower handover delays, packet loss, and signalling overhead with an increased level of security as compared to the standard Mobile IPv6's Return-Routability-based Route Optimization (RR-RO).

The fast handover Mobile IPv6 (FMIPv6) offers a handover preparation mechanism for a mobile node (MN) to reduce the handover latency over wireless network. However, FMIPv6 mainly deals with one MN instead of multiple MNs. In the wireless network, a group of MNs may move from the same previous network to the next network. In this paper, a group-based fast handover (GB-FH) control scheme is proposed to resolve the aforementioned problem. For the proposed GB-FH scheme, one MN initiates a handover preparation and other neighboring MNs can join the handover preparation using the “hitch-and-ride” concept, which means that when one MN is preparing for a handover, its neighbours can join the on-going handover preparation. Through the use of the shared invocation of the handover preparation procedure, (1) the handover preparation delay and handover latency can be reduced for about 20% and 8% respectively comparing with FMIPv6, (2) handover control messages can be reduced for about 57% comparing with FMIPv6 and (3) the contention of the wireless channel for multiple MNs can be improved due to the use of fewer control messages.

The route optimization operation in Mobile IP Version 6 (MIPv6) allows direct routing from any correspondent node to any mobile node and thus eliminates the problem of "triangle routing" present in the base Mobile IP Version 4 (MIPv4) protocol. Route optimization, however, requires that a mobile node constantly inform its correspondent nodes about its new care-of addresses by sending them binding update messages. Unauthenticated or malicious binding updates open the door for intruders to perform redirect attacks, i.e., malicious acts which redirect traffic from correspondent nodes to locations chosen by intruders. How to protect binding update messages to defend against redirect attacks is a challenging problem given the open environment in which MIPv6 operates. In this paper, we first look at two solutions proposed by the IETF Mobile IP Working Group and point out their weaknesses. We then present a new protocol for securing binding update messages. We also show that our protocol achieves strong security and at the same time is highly scalable to wide spread deployment.

The current deployment of wireless mesh networks requires mobility management to track the current locations of mobile nodes around the network without service interruption. To do so, the Hierarchical Mobile IPv6 protocol has been chosen, which minimises the required signalling by introducing a new entity called the mobile anchor point to act as a local home agent for all visiting mobile nodes in a specific domain. It allows a mobile node to register its local/regional care-of addresses with a mobile anchor point by sending a local binding update message. However, the local binding update is quite sensitive; it modifies the routing to enable mobility in the wireless mesh networks. When a local binding update message is spoofed, an attacker can redirect traffic that is destined for legitimate mobile node either to itself or to another node. This situation leads to an increased risk of attacks. Therefore, this paper contributes to addressing this security issue based on wireless mesh networks by cryptography generation and verification of a mobile node’s local and regional care-of addresses, as well as the application of a novel method to verify the reachability of mobile node at claimed local care-of address. This is called the enhanced mobile anchor point registration protocol. The Scyther tool has been used to ensure the proposed protocol accuracy. Furthermore, the performance, in terms of the mobile anchor point registration delay and signalling overhead, is evaluated by using the OPNET modeller simulator.

Hierarchical Mobile IPv6 (HMIPv6) has been proposed by the Internet Engineering Task Force (IETF) to reduce handoff latency and signaling overhead. In the new protocol, Mobility Anchor Point (MAP) receives all packets in place of Mobile Node (MN) and MAP services are transferred to Care of Address (CoA) of MN. However, a MAP may be a single point of performance bottleneck because the MAP should not only handle signaling traffic but also process data tunneling traffic for all MNs registered in a MAP domain. So, MAPs need MAP management scheme for the multimedia services or real time services. We propose a MAP selection scheme that can select different MAPs according to the traffic characteristics of MNs and a multilevel queue processing method that can process binding updates based on the priorities of queues in a MAP when MNs send BU. Quantitative results of the performance analysis show that our proposal can reduce the location update cost by 31% and the total cost by 14%. With the multilevel queues, we could reduce the total cost by 12% and 17% for D=4 and D=8 respectively.

Mobile IPv6 is a key technology in IPv6 to support the mobility of wireless communication terminals. In mobile IPv6, home agents (HAs) are responsible for the registration of mobile nodes (MNs) in the home network, and tunneling the data packets to the MNs when the MNs are not reachable through its home IP addresses. However recent research shows that the traffic bottleneck could be formed at a HA. When the HA experiences high intensity of the tunneled traffic and the MH registration information. In this paper, we propose a hybrid load balance mechanism which takes account of not only the MN registration information but also the tunneled data traffic information to effectively release and prevent the formation of the traffic bottleneck at the HA. We show that the proposed mechanism can be implemented in mobile IPv6 without changing the protocols of the communication between HAs and MNs in IETF MIPv6 draft. Simulation shows that our proposed algorithm can reduce the traffic delay substantially and the buffer requirements during the tunneling traffic phase in mobile IPv6.

본 논문에서는 신속한 이동성 관리기법인 FMIPv6(fast mobile IPv6)를 리눅스 기반으로 구현하여 기존 시스템과의 성능을 비교 실험하였다. FMIPv6 기법은 제 2계층의 동작에 의존하고 있기 때문에 이에 맞게 네트워크 드라이브를 수정하여 단말의 이동에 따라 제2계층에서의 트리거를 발생하도록 하였고 액세스 라우터와 이동 노드로 동작을 구분하여 설계하여 구현하였다. 구현된 시스템으로 기존 MIPv6(mobile IPv6)가 적용됐을 때와 비교하여 핸드오버기간동안의 패킷손실과 지연특성을 실험하였으며 FMIPv6에서의 개선된 성능을 고찰 하였다. In this paper, we implement the fast handovers for mobile IPv6 (FMIPv6) on Linux system. Due to its dependency on operations in layer-2 (L2), we have added some functions into the network driver to generate triggers as the mobile node moves. We design and implement the FMIPv6 functions divided into two parts as an access router and a mobile node. We compare the packet loss and delay of the FMIPv6 implementation during the handover period with those of the MIPv6 and investigate the performance improvement.