[Show abstract][Hide abstract] ABSTRACT: Opportunistic routing is a new routing paradigm that takes advantage of the broadcast characteristic of a wireless channel for data delivery in a wireless mesh network. Network coding has recently emerged as a new coding paradigm that can significantly improve the throughput performance of a WMN. In this article we explore the combination of opportunistic routing and network coding for improving the performance of a WMN. We first review existing opportunistic routing and coding-aware routing protocols, respectively, classify these protocols based on different criteria, and discuss their merits and drawbacks. We then propose a coding- aware opportunistic routing mechanism that combines hop-by-hop opportunistic forwarding and localized inter-flow network coding for improving the throughput performance of a WMN. Through opportunistic forwarding, CORE allows the next-hop node with the most coding gain to continue the packet forwarding. Through localized network coding, CORE attempts to maximize the number of packets that can be carried in a single transmission. Simulation results show that CORE can significantly improve the throughput performance of a WMN as compared with existing protocols.
[Show abstract][Hide abstract] ABSTRACT: This special issue includes a collection of 19 outstanding research papers which cover a diversity of topics on the application of network coding in wireless communication networks.
Full-text · Article · Jul 2009 · IEEE Journal on Selected Areas in Communications
[Show abstract][Hide abstract] ABSTRACT: In this paper, we study shortest-path routing in wavelength-routed optical networks with an objective to optimize the average-case running time for path computation. Four fast routing algorithms are proposed for dynamically computing the shortest lightpaths or semilightpaths in a network with or without wavelength converters. To reduce the average-case running time for path computation, sequential search, backward routing, and informed search are used in the algorithm design. Simulation results show that the proposed algorithms can significantly reduce the average-case computational overhead for path computation as compared with existing algorithms.
No preview · Article · Aug 2008 · Journal of Lightwave Technology
[Show abstract][Hide abstract] ABSTRACT: An ad-hoc wireless network is a collection of nodes that come together to
dynamically create a network, with no fixed infrastructure or centralized
administration. An ad-hoc network is characterized by energy constrained nodes,
bandwidth constrained links and dynamic topology. With the growing use of
wireless networks (including ad-hoc networks) for real-time applications, such
as voice, video, and real-time data, the need for Quality of Service (QoS)
guarantees in terms of delay, bandwidth, and packet loss is becoming
increasingly important. Providing QoS in ad-hoc networks is a challenging task
because of dynamic nature of network topology and imprecise state information.
Hence, it is important to have a dynamic routing protocol with fast re-routing
capability, which also provides stable route during the life-time of the flows.
In this thesis, we have proposed a novel, energy aware, stable routing
protocol named, Stability-based QoS-capable Ad-hoc On-demand Distance Vector
(SQ-AODV), which is an enhancement of the well-known Ad-hoc On-demand Distance
Vector (AODV) routing protocol for ad-hoc wireless networks. SQ-AODV utilizes a
cross-layer design approach in which information about the residual energy of a
node is used for route selection and maintenance. An important feature of
SQ-AODV protocol is that it uses only local information and requires no
additional communication or co-operation between the network nodes. SQ-AODV
possesses a make-before-break re-routing capability that enables near-zero
packet drops and is compatible with the basic AODV data formats and operation,
making it easy to adopt in ad-hoc networks.
[Show abstract][Hide abstract] ABSTRACT: In this paper, we study the issue of dynamically selecting shortest paths in wavelength-routed networks. We present several fast shortest path selection algorithms for networks with and without wavelength conversions. The presented algorithms employ the strategies of sequential search, backward routing, and informed search. Simulation results demonstrate that our presented algorithms can significantly reduce the average-case running time in identifying shortest paths in wavelength-routed networks.
[Show abstract][Hide abstract] ABSTRACT: The group addressing model currently employed for supporting IP multicast has caused several implementation issues including global unique address allocation, sender admission control, and multicast forwarding state scalability. In this article we first review related work carried out to address these issues using different mechanisms and at different levels. We discuss their merits and deficiencies and also their possible combinations for improved performance. We then devise a protocol that works by introducing the idea of recursive unicast into an existing multicast routing protocol, multicast extension to OSPF (MOSPF), to achieve scalable multicast. Simulation results are used to demonstrate the high performance of the devised protocol in reducing computational overhead and forwarding state at routers and also in casing address allocation and admission control.
Preview · Article · Feb 2005 · IEEE Communications Magazine