Mohammed Balfaqih

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.

Proxy Mobile IPv6 Handover Management in Vehicular Networks: State of the Art, Taxonomy and Directions for Future Research

Abstract In vehicular communication networks, to facilitate the variety of intelligent transportation system (ITS) applications, handover management is considered as the one of the most challenging research issues. The most compatible and interoperable handover management solutions are designed based on IP mobility protocols. However, due to the unique characteristics of vehicles such as high velocity, IP mobility management protocols are still unacceptable for ITS real-time applications that are sensitive to network latencies. Thus, whenever the vehicle roams between two domains, which is most likely to occur in vehicular networks, its reachability status will be broken-down causing high handover latency and inevitable traffic loss. Recently, proxy mobile IPv6 (PMIPv6) has been proposed to support the mobility management without any intervention of the mobile user in the mobility-related signaling. As PMIPv6 will be deployed in the wireless technologies for next generation networks (i.e., LTE/LTE-advanced, WiFi and WiMAX), vehicular ad hoc networks (VANETs) are expected to employ PMIPv6 protocol in vehicle to infrastructure connection as well. In this paper, we introduce a comprehensive review of the state of the art of PMIPv6 handover management in VANET. We present a new taxonomy and classify the existing schemes according to different considerations. Finally, we outline several open issues and handoff management design considerations as a direction for future research.

802.21-Assisted Distributed Mobility Management Solution in Vehicular Networks

Recently, distributed mobility management (DMM) solutions have been proposed to address the drawbacks of centralized mobility management (CMM) solutions. The Internet engineering task force (IETF) has stated that extending and reusing CMM protocols are one of the considerations for DMM solutions design, where it is less faulty and more effective. Therefore, IETF has proposed a network-based DMM solution based on the well-known network-based CMM protocol: Proxy Mobile IPv6 (PMIPv6). However, network-based DMM has marginal improvements over the handover latency and packet loss of PMIPv6. Thus, this paper enhances the handover procedure of network-based DMM using the HO-initiate process and the IEEE 802.21 media-independent handover services. We tackle the issue of binding registration latency by performing the HO-initiate process proactively. Moreover, we mitigate the latency of discovering next access network and candidate mobile anchor access routers (MAARs) with the support of the lower three layers’ information of the mobile user and surrounded MAARs. A neighbors network information container is introduced to store and retrieve the link and network layers’ information of neighboring networks. A candidate access networks cache is defined at the serving-MAAR to decrease the prediction time. Furthermore, we propose a candidate access network selector to facilitate smart handover decision making by using the information of required and available resources in the candidate networks. We derive an analytical expression to evaluate the proposed solution compared with DMM and fast handover for DMM mechanisms. Simulation is also performed to verify the analytical results, where we consider realistic urban and highway environments. Numerical and simulation results prove that the proposed solution decreases 74.61% of the overall handover latency in DMM.

Handover performance analysis of distributed mobility management in vehicular networks

The provision of seamless mobility is crucial for an efficient support of global roaming in vehicular networks. The most compatible and interoperable handover management solutions are designed based on IP mobility protocols. Current IP mobility management protocols, including Proxy Mobile IPv6 (PMIPv6), rely on centralized and static mobility anchor, which intrinsically pose enormous burdens on the central anchors in terms of user mobility management and connectivity needs. Recently, network-based Distributed Mobility Management (DMM) based on PMIPv6 has been proposed to overcome the aforementioned issues. In this paper, we study the worth of adopting network-based in vehicular networks. We analyze and compare the handover performance of network-based DMM with PMIPv6. For handover analysis, the effect of system parameters, such as vehicle velocity, radius of cells, and network scale are investigated with respect to handover latency and packet loss metrics. Numerical results show that network-based DMM outperforms PMIPv6.

An Adaptive Multi-Channel Assignment and Coordination Scheme for IEEE 802.11P/1609.4 in Vehicular Ad-Hoc Networks

Vehicular ad-hoc networks (VANETs) have been developed to provide safety-related and commercial service applications on the road. The IEEE 1609.4 is a standard (legacy) designed to support multi-channels in VANETs, namely control channel (CCH) and service channels (SCHs) with fixed alternating CCH and SCH intervals. The CCH is dedicated to broadcast safety and control applications while SCHs are used to transfer service data applications. However, due to the nature of contention-based channel access scheme and the transmission of multiple applications over the CCH during a fixed interval, safety applications performance is degraded during CCH congestion in high network density scenarios. In this paper, we propose an adaptive multi-channel assignment and coordination (AMAC) scheme for the IEEE 802.11p/1609.4 in VANETs which exploits channel access scheduling and channel switching in a novel way. AMAC scheme includes an adaptive execution of the peer-to-peer negotiation phase between service providers and users for SCH resource reservations, and collision-aware packet transmission mechanisms. These two mechanisms alleviate collisions and increase packet delivery ratio (PDR) of safety applications on the CCH. Thereby, the AMAC scheme ensures an efficient and reliable quality of service (QoS) for different traffic flows and improves the time diversity among vehicles based on the traffic conditions. For performance analysis, analytical models are developed based on 1-D and 2-D Markov chain models taking into account an error-prone channels. The probabilities of successful transmission and collisions have been derived to compute PDR, and delay for safety packets in legacy standard and AMAC scheme. Analytical and simulation results indicate that the AMAC scheme reduces the collisions and increases the PDR for safety applications over the CCH compared with the legacy standard. In addition, AMAC scheme outperforms the legacy standard in terms of system throughput of service applications.

Topology sense and graph-based TSG: efficient wireless ad hoc routing protocol for WANET

Technologies such as wireless ad hoc have undergone rapid redesigning. The routing protocol plays an essential role in improving the performance of wireless networks. However, improving the routing efficiency of a WANET still faces two main challenging issues: the routing table size and routing protocol selection criteria from the source to destination. This paper propose an efficient routing protocol using the Graph theory. In reviewing previous work, so far no research has represented routing information by a Triangular Matrix Table (TMT). TMT is based on the graph theory to save the entire network topology in a small memory size. Due to node movement or shut down, all neighboring nodes can detect that, namely, topology sense. The proposed Topology Sense and Graph-base (TSG) protocol relies on the topology change only. Node can send update message to all nodes by a distributor-cast mechanism, thus guaranteeing that every node gets one updating message. This mechanism depends on the TMT and Spanning Tree algorithm. The simulation results show that the TSG performs better than the conventional routing protocols. As a consequence, the throughput, delay time, packet loss, and overhead message are significantly improved as verified by NS3.

Design and evaluation of network-based distributed mobility management solution based on PFMIPv6

Proxy Mobile IPv6 (PMIPv6) protocol provides IP mobility support to a Mobile User (MU) once it performs a handover from an access router to another. Furthermore, Fast Handover for PMIPv6 (PFMIPv6) protocol has been standardized to improve the handover performance of PMIPv6 in terms of handover latency and packet loss. The limitation of these Centralized Mobility Management (CMM) protocols (e.g., non optimal routes, single point of failure and scalability) has led to the development of Distributed Mobility Management (DMM) paradigm. DMM aims to flat the network architecture by placing the anchor entity dynamically closer to the MU. The DMM solutions can be classified into: host-based DMM, in which MU participates in IP mobility process, and network-based DMM, where IP mobility process is done in the network side without MU involvement. However, existing network-based DMM proposals rely on PMIPv6 protocol which experience high handover latency and packet loss. Thus, we present the design and operation of a proposed network-based DMM solution based on PFMIPv6. We have developed an analytical model to evaluate and compare the handover latency and the packet loss of the proposed network-based DMM solution and IETF networkbased DMM proposal.