Showing papers by "Tinku Rasheed published in 2009"

Towards Efficient Geographic Routing in Urban Vehicular Networks

Abstract: Vehicular ad hoc networks (VANETs) have received considerable attention in recent times. Multihop data delivery between vehicles is an important aspect for the support of VANET-based applications. Although data dissemination and routing have extensively been addressed, many unique characteristics of VANETs, together with the diversity in promising applications, offer newer research challenges. This paper introduces the improved greedy traffic-aware routing protocol (GyTAR), which is an intersection-based geographical routing protocol that is capable of finding robust and optimal routes within urban environments. The main principle behind GyTAR is the dynamic and in-sequence selection of intersections through which data packets are forwarded to the destinations. The intersections are chosen considering parameters such as the remaining distance to the destination and the variation in vehicular traffic. Data forwarding between intersections in GyTAR adopts an improved greedy carry-and-forward mechanism. Evaluation of the proposed routing protocol shows significant performance improvement in comparison with other existing routing approaches. With the aid of extensive simulations, we also validate the optimality and sensitivity of significant GyTAR parameters.

On tree-based routing in multi-gateway association based Wireless Mesh Networks

Abstract: There is an increasing acceptance for Wireless Mesh Networks (WMN) as the potential ‘last-mile’ access technology running media-rich applications with stringent quality of service (QoS) requirements. As WMNs are envisioned to provide high bandwidth broadband services to a large community of users, the Internet Gateway which acts as a central point of attachment for the mesh routers is likely to be a potential bottleneck because of its limited wireless link capacity. We propose TBMGA (Tree-Based with Multi-gateway Association), a novel routing protocol that elegantly balances the load among the different Internet gateways in a WMN. With TBMGA, we combine the flexibility of layer-2 routing with the self-configuring and self-healing capabilities of MANET routing. TBMGA switches the point of attachment of an active source-serviced gateway depending on a global metric estimated based on the average queue length and expected availability at the Internet gateway. The protocol is evaluated using simulations and we observe that the proposed scheme is able to efficiently balance the traffic between multiple gateways.

Completing the convergence puzzle: a survey and a roadmap

Abstract: Convergence has more than ever been a central issue for fixed and mobile operators throughout the world and is considered to be the next big step in the evolution of telecommunication networks. Convergence opens new market opportunities and competition among network operators and above all offers enhanced user experience. Multimode handsets and the proliferation of terminals and access technologies are generating increasing demands for solutions that enable convergence, seamless handover, and transparent service delivery across heterogeneous access networks. Different strategies are available for operators, depending on the services they intend to deliver to their customers, from basic commercial convergence limited to unified billing for Fixed/Mobile/Internet up to in-dept network convergence covering new applications and services. This article surveys different technologies which offer seamless handover and converged access to mobile voice, video, and data services. It provides first the different network parts involved in defining the operator global convergence strategy and then surveys different technologies which achieve this step-by-step convergence. We present the main features of these technologies and discuss their limitations and potentials to enable convergence in heterogeneous networks. We also provide a personal stance as to the emergence of these technologies and our vision towards the long term converged telecommunication networks.

Mesh your Senses: Multimedia Applications over WiFi-based Wireless Mesh Networks

Abstract: This demo aims at (i) validating the design choices we have made in conceiving and deploying the WING testbed, and (ii) showing the capability of out software toolkit to properly support heterogeneous multimedia applications. Additionally, the mesh networking toolkit's fault management features is demonstrated. We hope that our wireless mesh networking toolkit is considered by both researchers and practitioners as platform of choice to test innovative solutions and to provide end-users with wireless connectivity. WING is an experimental multi-radio WMN testbed designed and built exploiting commodity hardware and open-source software components. WING implements a flexible and scalable WMN architecture capable of supporting next-generation Internet services with a particular focus on multimedia applications. The WING project aims at providing an open-platform on top of which innovative solution can be implemented and tested in a realistic environment. Currently, the testbed consist of 10 nodes deployed at CREATE-NET premises and implementing a two-tiers architecture. Other well-known IEEE 802.11-based WMNs include Roofnet, Hyacinth, Microsoft's MCL, and Meraki. We establish the uniqueness of our mesh solution in that it is capable of achieving both service differentiation and performance isolation in IEEE 802.11-based WMNs. While not providing strict QoS performance bounds, the proposed scheme aims at enhancing the perceived quality of experience by combining opportunistic scheduling and packet aggregation and by implementing a DiffServ-like architecture in order to provide traffic prioritization.

Media Independent Handover in heterogeneous multi-hop mobile networks

Abstract: In next generation wireless systems, achieving seamless service continuity when transitioning between heterogeneous networks is a challenging task. An approach to optimize these handover procedures through the introduction of a standardized framework is followed by the IEEE 802.21 working group. The Media Independent Handover (MIH) function of IEEE 802.21 is mainly designed for "client-network" scenarios and not applicable to multi-hop connectivity models. In this paper, we propose an extended MIH model for accommodating multi-hop mode of operation in heterogeneous mobile networks. Our objective is to effectively use the services and the messages associated to the framework, so as to enhance the scope of MIH functionality and contrastingly, enable multi-hop heterogeneous networking in personal ubiquitous environments [16].

On the support of multimedia applications over IEEE 802.11-based wireless mesh networks

Abstract: The extended radio coverage provided by wireless mesh networking (WMN) technologies represents a key advantage compared to the last mile solutions based on standard IEEE 802.11 hot spots. Nevertheless, modern requirements to wireless connectivity include mandatory QoS guarantees for a wide set of real-time applications. In this paper, we first propose a methodology for evaluating multimedia applications over real world WMN deployments and then we report the results of an extensive measurement campaign performed exploiting IEEE 802.11-based WMN testbed. Later, we evaluate the QoS performance of the reference multimedia applications exploiting three different link scheduling disciplines. Results show that, using opportunistic scheduling techniques capable of providing performance isolation among competing flows can significantly improve system capacity.