Hazy Sighted Link State Routing Protocol

About: Hazy Sighted Link State Routing Protocol is a research topic. Over the lifetime, 6936 publications have been published within this topic receiving 169377 citations. The topic is also known as: HSLS.

Distributed QoS routing with imprecise state information

Abstract: The goal of quality-of-service (QoS) routing is to find a network path which has sufficient resources to satisfy certain constraints on delay, bandwidth and/or other metrics. The network state information maintained at every node is often imprecise in a dynamic environment because of nonnegligible propagation delay of state messages, periodic updates due to overhead concern, and hierarchical state aggregation. The information imprecision makes QoS routing difficult. The traditional shortest-path routing algorithm does not provide satisfactory performance with imprecise state information. We propose a distributed routing scheme, called ticket-based probing, which searches multiple paths in parallel for a satisfactory one. The scheme is designed to work with imprecise state information. It allows the dynamic trade-off between the routing performance and the overhead. The state information of intermediate nodes is collectively used to guide the routing messages along the most appropriate paths in order to maximize the success probability. The proposed algorithm consider not only the QoS requirements but also the cost optimality of the routing path. Extensive simulations show that our algorithm achieve high call-admission ratio and low-cost routing paths with modest overhead. The algorithm can tolerate high degree of information imprecision.

Scalable ad hoc routing: the case for dynamic addressing

Abstract: We show that the use of dynamic addressing can enable scalable routing in ad hoc networks. It is well known that the current ad hoc protocol suites do not scale to work efficiently in networks of more than a few hundred nodes. Most current ad hoc routing architectures use flat static addressing and thus, need to keep track of each node individually, creating a massive overhead problem as the network grows. Could dynamic addressing alleviate this problem? To begin to answer this question, we provide an initial design of a routing layer based on dynamic addressing, and evaluate its performance. Each node has a unique permanent identifier and a transient routing address, which indicates its location in the network at any given time. The main challenge is dynamic address allocation in the face of node mobility. We propose mechanisms to implement dynamic addressing efficiently. Our initial evaluation suggests that dynamic addressing is a promising approach for achieving scalable routing in meganode ad hoc networks.

Efficient Protocols for Signing Routing Messages.

Abstract: In this work, we aim to reduce the computational costs of using public-key digital signatures in securing routing protocols. Two protocols (COSP and IOSP) using one-time digital signatures are introduced to provide the functionality of public-key digital signatures. Our protocols are intended to be used in place of public-key digital signatures for signing all kinds of message exchanges among routers. We obtained more than ten-fold increase in speed compared with public-key signatures. Our protocols overcome the shortcomings identified in previous works, such as timing constraints, limited applications and high storage and computational costs for volatile environments [12]. Since our protocols are non-interactive, they provide full functionality of a true signature. However, our protocols are not intended for replacing public-key infrastructures completely. Instead, public-key infrastructures are used to set up COSP and IOSP. As a general approach, our protocols can be used with public-key cryptosystems for efficient message signing in much the same way as secret-key cryptosystems are used in conjunction with public-key systems for efficient data encryption.

A framework for adaptive routing in multicomputer networks

Abstract: Message-passing concurrent computers, also known as multicomputers, such as the Caltech Cosmic Cube [47] and its commercial descendents, consist of many computing nodes that interact with each other by sending and receiving messages over communication channels between the nodes. The communication networks of the second-generation machines, such as the Symult Series 2010 and the Intel iPSC2 [2], employ an oblivious wormhole-routing technique that guarantees deadlock freedom. The network performance of this highly evolved oblivious technique has reached a limit of being capable of delivering, under random traffic, a stable maximum sustained throughput of ~~45 to 50% of the limit set by the network bisection bandwidth, while maintaining acceptable network latency. This thesis examines the possibility of performing adaptive routing as an approach to further improving upon the performance and reliability of these networks. In an adaptive multipath routing scheme, message trajectories are no longer deterministic, but are continuously perturbed by local message loading. Message packets will tend to follow their shortest-distance routes to destinations in normal traffic loading, but can be detoured to longer but less-loaded routes as local congestion occurs. A simple adaptive cut-through packet-switching framework is described, and a number of fundamental issues concerning the theoretical feasibility of the adaptive approach are studied. Freedom of communication deadlock is achieved by following a coherent channel protocol and by applying voluntary misrouting as needed. Packet deliveries are assured by resolving channel-access conflicts according to a priority assignment. Fairness of network access is assured either by sending round-trip packets or by having each node follow a local injection-synchronization protocol. The performance behavior of the proposed adaptive cut-through framework is studied with stochastic modeling and analysis, as well as through extensive simulation experiments for the 2D and 3D rectilinear networks. Theoretical bounds on various average network-performance metrics are derived for these rectilinear networks. These bounds provide a standard frame of reference for interpreting the performance results. In addition to the potential gain in network performance, the adaptive approach offers the potential for exploiting the inherent path redundancy found in richly connected networks in order to perform fault-tolerant routing. Two convexity-related notions are introduced to characterize the conditions under which our adaptive routing formulation is adequate to provide fault-tolerant routing, with minimal change in routing hardware, The effectiveness of these notions is studied through extensive simulations, The 2D octagonal-mesh network is suggested; this displays excellent fault-tolerant potential under the adaptive routing framework. Both performance and reliability behaviors of the octagonal mesh are studied in detail. A number of

System and method for achieving continuous connectivity to an access point or gateway in a wireless network following and on-demand routing protocol, and to perform smooth handoff of mobile terminals between fixed terminals in the network

Abstract: A system and method for enabling an ad-hoc communication network to maintain connectivity with the mobile nodes in the network in an effective and efficient manner with minimal overhead (Fig. 1). The system and method enables an ad-hoc communication network to maintain connectivity between intelligent access points of the network and mobile nodes in the network while performing an on-demand protocol. The system and method further uses an improved distance vector routing algorithm and unicast messages, to thus avoid an increase routing advertisement frequency in the network while keeping network overhead at a minimum. The system and method also modifies the Ad Hoc On-Demand Distance Vector Routing (AODV) protocol to facilitate smooth handoff of subscriber devices in an ad-hoc communication network while also eliminating unidirectional links between nodes in the network.