Browsing by Author "Islam, Shayla"

With the worldwide deployment of different wireless access technologies and increasing demands for global Internet connectivity, Network Mobility (NEMO) is becoming more demanding technology. As a result, NEMO Basic Support Protocol (NEMO BSP) has been proposed by the NEMO working group for the continual worldwide connectivity of each node within the mobile network. The existing NEMO-BSP is capable to register only single primary Care of Address (CoA) of Mobile Router (MR) during movement among different networks. Thus, it creates the problem of network connectivity when this link fails. This is because, no secondary options remain to keep the continuous Internet connectivity in NEMO. As a result, applying multihoming technique at any place, anywhere to provide uninterrupted Internet connection in NEMO is becoming a significant area for the current researchers. When mobile network is multihomed, it is possible to achieve some features namely increased availability, balanced traffic load with flow distribution through simultaneous connectivity to access router. Therefore, the IETF Mobility Extensions (MEXT) group introduces multihoming concept (i.e. MCoA registration with flow findings) as an extension of NEMO-BSP. This is to support simultaneous use of multiple interfaces or IP addresses on a single MR (i.e. Multihomed MR). As a result, it is possible to avoid single point of failure during handoff in NEMO. However, this scheme inherits the standard MIPv6 drawbacks such as creating bi-directional tunnel as well as exchanging the mobility-related Layer 3 (L3) signaling messages through the wireless link. This can be addressed via integrating the flow bindings with Proxy MIPv6 (PMIPv6). Nevertheless, adding this function of IP flow bindings during inter technology handoff on PMIPv6 in NEMO (i.e. P-NEMO) network is still a challenging issue since consideration has to be given on both MR and its Mobile Network Nodes (MNNs) in the P-NEMO environment. MRs are not capable to use multiple interfaces simultaneously during the movement among different access technologies in P-NEMO environment. This ultimately degrade the network performance (i.e. lower throughput and PDR) as well as increase handoff delay and packet loss. Moreover, the tunneling overhead increases as the number of MNN increases in P-NEMO environment. This results in increasing the total handoff cost in terms of signaling cost and packet delivery cost. Therefore, the main aim of this research is to propose a novel Multihoming-based scheme to support Mobility management in PNEMO (MM-PNEMO) environment. Besides, the performance is evaluated using both numerical and simulation approaches to validate the applicability and efficiency of the proposed scheme. The performance metrics used for evaluation are namely handoff delay, packet loss, packet delivery ratio, throughput and total handoff cost. The proposed scheme is benchmarked with the standard NEMO-BSP and P-NEMO scheme. The analytical result shows that the proposed scheme reduces average handoff cost by 64% lower compared to the NEMO-BSP and PNEMO. The simulation is done using Network Simulator version 3 (NS-3). The simulation result shows that the proposed scheme outperforms the standard NEMO BSP and P-NEMO in terms of packet loss (less than 1%) and handoff delay (average improvement by 76%).

In order to support mobile network, a management mechanism of Network Mobility Basic Support Protocol (NEMO BSP) has been standardized by Information Engineering Task Force (IETF). NEMO BSP is an extension of Mobile IPv6 (MIPv6) and inherits all the shortcomings like higher handoff latency, packet loss etc. As Network Mobility (NEMO) is engagedto manage the movement of Mobile Router (MR) and it's Mobile Network Nodes (MNNs) during handoff, it is very important to improve the performance of mobility management protocol to achieve seamless handoff with lower delay and packet loss in NEMO environment.The diversity of location of different nodes and complexity of NEMO route optimization procedure result in several rounds of signaling messages. Also longer time is required to complete handoff process which may cause performance degradation of the applications running on Mobile Network Nodes (MNNs). Additionally, when a change in point of attachment of the mobile network is accompanied by a sudden burst of signaling messages, "Signaling Storm" occurs and it ultimately results in temporary congestion, handoffdelays, or even packet loss. This effect is especially noteworthy for wireless environment where bandwidth is relatively limited. Therefore providing uninterrupted Internet connection, applying route optimization and multihoming technique in NEMOare becoming most significant areas for current researchers. In case of Mobile IPv6 network, Fast Handover Scheme for Hierarchical Mobile IPv6 (FHMIPv6) works successfully as a host mobility solution. However,in NEMO environment applying FHMIPv6 mechanism is a challenging task asboth MR and its MNNs need to be considered. The aim of this research is to enhance mobility management mechanisms in NEMO environment with the intention of establishing uninterrupted Internet connectionduring handoff. It proposes a Macro Mobility Scheme (MM-NEMO)in NEMO networkin order to achieve the seamless handoff. This is achieved by integrating improved FHMIPv6 scheme with NEMO networks. Theperformance of the proposed scheme is evaluated using both analyticaland simulation approaches. The proposed scheme is benchmarked with the standard NEMO BSP. The performance metrics used for analytical evaluation are location update cost, packet delivery cost and cell residence time respectively. The analytical result shows that the total handoff cost for the proposed scheme is lower than that of NEMO-BSP. The simulation is done using Network Simulator (NS-2). The simulation result shows that the proposed scheme outperforms the standard NEMO BSP in terms of packet loss (less than 6%) and handoff latency(reduced to 42%).