Browsing by Author "Ibrahim, Loay Faisal"

Quality of Service (QoS) is defined as the capability of network elements (e.g. application, host and router) to provide some sort of assurance and service differentiation for consistent network data delivery. Internet Engineering Task Force (IETF) has endorsed Network Mobility Basic Support (NEMO BS) protocol (RFC 3963) to address the challenges of the entire network mobility (such as the movements of trains, buses, ships and aircrafts). However, NEMO BS is designed without QoS support in mind. Similar to MIPv6, it can hardly offer same level of services (i.e. Best-Effort) to all the users without obligation to the applications needs. This poses a problem to real-time applications that required certain level of QoS commitment. Moreover, delays in data delivery, packet loss and higher signalling overheads are likely to transpire because of suboptimal routing and multiple encapsulations of data packets. Incorporating QoS with mobility support seems to be needed to fulfil the necessity of users in mobile network. This thesis proposes a new scheme that deploys Differentiated Service (DiffServ) QoS-based model to achieve smooth delivery of real-time traffic in heterogeneous mobile networks. Furthermore, the proposed scheme uses the mechanisms of Fast Hierarchical Mobile IPv6 (FHMIPv6) to reduce location update signalling issues, since the MR doesn't concern about local and global moventment. It also conquers the weakness of NEMO inefficient routing by utilizing the methodology of MIPv6 route optimization to bypass the HA and catering optimal path. The feasibility of the proposed scheme is evaluated using two methods namely, simulation (i.e. NS-2) and analytical approach. The performance of proposed scheme is benchmarked with the standard NEMO basic support protocol. Eventually, the simulation results reflect that the proposed scheme outperforms the standard NEMO BS protocol by alleviating the packet loss and diminishing the handover latency, even though when the velocity of mobile router reached up to 90 Km/h. On the other hands, the analytical results show that the proposed scheme obtained noticeable performance improvement by reducing the signalling cost when the network size is increased.

Supporting Quality of Service (QoS) in the Internet is considered one of the main challenges facing many researchers nowadays. QoS is the ability of network elements (e.g. application, host and router) to provide some level of assurance for consistent network data delivery. The standard Mobile IPv6 was designed to allow nodes to be reachable and maintain ongoing connections while changing their location within the topology. However, it can only provide Best-Effort services to its applications, i.e. there is no QoS commitment offered. The Best-Effort service works fine with the conventional Internet applications (non real-time applications) such as remote login, electronic mail and file transfer. In contrary, real-time applications like video telephony and virtual conferencing require QoS guarantee in lieu of the Best-Effort delivery. As a result, Internet Engineering Task Force (IETF) has proposed three major models to support QoS in the Internet namely, IntServ, DiffServ and MPLS. Above all, the most promising one due to its simplicity and scalability advantages is DiffServ. Nevertheless, those approaches were initially designed without mobility inmind. Hence, they are not fully adapted to mobile environments yet. Integrating QoS with mobility support seems to be needed to fulfill the necessity of users. This dissertation aims to propose a new scheme that takes the advantage of DiffServ to enhance QoS in the mobile IPv6 networks. The proposed scheme was evaluated using two methods namely, simulation and analytical analysis. The proposed scheme is benchmarked with the standard MIPv6 which was proposed by IETF. The obtained results show that the proposed scheme outperforms the standard MIPv6 protocol in terms of packets loss and handover latency. Therefore, the probability of dropping BUs might reach to more than 20% in the MIPv6 which is adversely affects the handover performance. On the other hand when the BU is assigned with high priority as in the proposed scheme (DiffServ-MIPv6), the drop is not often encountered even if the network was congested.