15 research outputs found

    A survey of flooding, gossip routing, and related schemes for wireless multi- hop networks

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    Flooding is an essential and critical service in computer networks that is used by many routing protocols to send packets from a source to all nodes in the network. As the packets are forwarded once by each receiving node, many copies of the same packet traverse the network which leads to high redundancy and unnecessary usage of the sparse capacity of the transmission medium. Gossip routing is a well-known approach to improve the flooding in wireless multi-hop networks. Each node has a forwarding probability p that is either statically per-configured or determined by information that is available at runtime, e.g, the node degree. When a packet is received, the node selects a random number r. If the number r is below p, the packet is forwarded and otherwise, in the most simple gossip routing protocol, dropped. With this approach the redundancy can be reduced while at the same time the reachability is preserved if the value of the parameter p (and others) is chosen with consideration of the network topology. This technical report gives an overview of the relevant publications in the research domain of gossip routing and gives an insight in the improvements that can be achieved. We discuss the simulation setups and results of gossip routing protocols as well as further improved flooding schemes. The three most important metrics in this application domain are elaborated: reachability, redundancy, and management overhead. The published studies used simulation environments for their research and thus the assumptions, models, and parameters of the simulations are discussed and the feasibility of an application for real world wireless networks are highlighted. Wireless mesh networks based on IEEE 802.11 are the focus of this survey but publications about other network types and technologies are also included. As percolation theory, epidemiological models, and delay tolerant networks are often referred as foundation, inspiration, or application of gossip routing in wireless networks, a brief introduction to each research domain is included and the applicability of the particular models for the gossip routing is discussed

    Routing performance in ad hoc networks.

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    Thesis (M.Sc.Eng.)-University of Natal, Durban, 2003.An ad hoc network is a multi-hop wireless network in which mobile nodes communicate over a shared wireless channel. The network is formed cooperatively without specific user administration or configuration and is characterised by a distributed network management system and the absence of a wired backbone. Military, law enforcement, and disaster relief operations are often carried out in situations with no pre-existing network infrastructure and can benefit from such networks because base stations, which are single points of failure, are undesirable from a reliability standpoint. The rising popularity of mobile computing has also created a potentially large commercial market for multimedia applications applied over wireless ad hoc networks. This dissertation focuses on the routing aspects of ad hoc networking. The multi-hop routes between nodes constantly change as the mobile nodes migrate. Ad hoc network routing algorithms must therefore adapt to the dynamic and unpredictable topology changes, the random radio propagation conditions and portable power sources. Various routing protocols have been proposed in the literature for ad hoc networks. These protocols together with comparative simulations are discussed and a new protocol based on load balancing and signal quality determination is proposed . and the simulation results are presented. Currently the proposed routing protocols are compared using simulation packages which are often time consuming. This dissertation proposes a mathematical model for evaluating the routing protocols and the resultant end-to-end blocking probabilities. The mathematical model is based on a derivation of the reduced load approximation for analysing networks modelled as loss networks and the evaluation incorporates and adapts models that have been used for the analysis of cellular Code Division Multiple Access (CDMA) systems. While analytical methods of solving blocking probability can potentially generate results orders of magnitude faster than simulation, they are more importantly essential to network sensitivity analysis, design and optimisation

    Mobility-adaptive clustering and network-layer multicasting in mobile ad hoc networks

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    Ph.DDOCTOR OF PHILOSOPH

    Study on enhancement of dominating sets in Ad Hoc wireless networks

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    An essential component of effective use of Ad Hoc Wireless networks is proper utilization of available resources and network stability. There has been a recent increase of interest in Ad Hoc networks, partly due to the fact that Ad Hoc networks can be implemented without requiring any support from existing wired backbone or costly hardware setup. The effective utilization of the power of the Ad Hoc networks lies in scalability, stability, maintainability and rapid convergence of these networks. The route detection and route formation in the Ad Hoc networks should be done instantaneously. Performing effective route detection on such environments can be best achieved when the broadcasting is improved and the redundancy in route detection is removed. In this thesis work, a cluster based algorithm as well as a localized algorithm for Connected Dominating Set formation have been proposed. The Clustering algorithm forms disjoint logical groups of nodes with a lead node as head of the cluster. The cluster head takes part in the routing and has additional tasks of cluster maintenance. The clusters form a logical backbone and the Route search space is limited to the no. of clusters. But, the method forms suboptimal routes. The Connected Dominating Set based algorithm forms a logical backbone of connected gateways. The broadcast packets are retransmitted by these nodes. The routes are computed by shortest path algorithm. Changes in the backbone does not have impact on the ongoing communications. New routes are computed upon failure of existing routes. The results obtained using this algorithm are compared with other methods across a range of different scenarios with 100 nodes upon a simulation area of 100 X 100 twips. The Connected Dominating Set algorithm distributes the dominating nodes equally along the entire range while others are being biased towards higher “id” nodes. The Connected Dominating Set based algorithm is excelling the cluster algorithm in Search space size

    Improving broadcast performance in multi-radio multi-channel multi-rate wireless mesh networks.

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    This thesis addresses the problem of `efficient' broadcast in a multi-radio multi-channel multi-rate wireless mesh network (MR2^2-MC WMN). In such a MR2^2-MC WMN, nodes are equipped with multiple radio network interface cards, each tuned to an orthogonal channel, that can dynamically adjust transmission rate by choosing a modulation scheme appropriate for the channel conditions. We choose `broadcast latency', defined as the maximum delay between a packet's network-wide broadcast at the source and its eventual reception at all network nodes, as the `efficiency' metric of broadcast performance. The problem of constructing a broadcast forwarding structure having minimal broadcast latency is referred to as the `minimum-latency-broadcasting' (MLB) problem. While previous research for broadcast in single-radio single-rate wireless networks has highlighted the wireless medium's `\emph{wireless broadcast advantage}' (WBA); little is known regarding how the new features of MR2^2-MC WMN may be exploited. We study in this thesis how the availability of multiple radio interfaces (tuned to orthogonal channels) at WMN nodes, and WMN's multi-rate transmission capability and WBA, might be exploited to improve the `broadcast latency' performance. We show the MLB problem for MR2^2-MC WMN to be NP-hard, and resort to heuristics for its solution. We divide the overall problem into two sub-problems, which we address in two separate parts of this thesis. \emph{In the first part of this thesis}, the MLB problem is defined for the case of single-radio single-channel multi-rate WMNs where WMN nodes are equipped with a single radio tuned to a common channel. \emph{In the second part of this thesis}, the MLB problem is defined for MR2^2-MC WMNs where WMN nodes are equipped with multiple radios tuned to multiple orthogonal channels. We demonstrate that broadcasting in multi-rate WMNs is significantly different to broadcasting in single-rate WMNs, and that broadcast performance in multi-rate WMNs can be significantly improved by exploiting the availability of multi-rate feature and multiple interfaces. We also present two alternative MLB broadcast frameworks and specific algorithms, centralized and distributed, for each framework that can exploit multiple interfaces at a WMN node, and the multi-rate feature and WBA of MR2^2-MC WMN to return improved `broadcast latency' performance

    The design and simulation of routing protocols for mobile ad hoc networks.

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    Thesis (Ph.D.)-University of Natal, Durban, 2000.This thesis addresses a novel type of network known as a mobile ad hoc network. A mobile ad hoc network is a collection of entirely mobile nodes that can establish communication in the absence of any fixed infrastructure. Envisioned applications of these networks include virtual classrooms, emergency relief operations, military tactical communications, sensor networks and community networking. Mobile ad hoc networking poses several new challenges in the design of network protocols. This thesis focuses on the routing problem. The main challenges in the design of a routing protocol for mobile ad hoc networks result from them having limited resources and there being frequent topological changes that occur unpredictably. Moreover, there is no fixed infrastructure that supports routing. The conventional routing protocols are not generally suitable for mobile ad hoc networks, as they cannot react quickly to the changing network topology, cause excessive communication and computation, or converge very slowly creating routing loops. In this thesis we propose two classes of routing schemes for mobile ad hoc networks. The first class is known as Limited Flooding Protocol. The protocol is fully reactive and does not require the computation of routing tables. It uses some basic principles of flooding, but reduces the communication overhead by restricting packet propagation through the network. Several variations of limited flooding are considered including deterministic, randomised and priority-based mechanisms. The main advantage of this protocol is that it can be used in networks with unpredictable topological changes and highly mobile nodes, since maintaining routing table at the intermediate nodes is not required. The second class of routing protocols is based on hierarchical clustering architecture and is intended for use in a relatively low mobility environment. The basic idea of this protocol is to partition the entire network into smaller units known as clusters and define routing mechanisms both within and between clusters using a hierarchical architecture. The main advantage of this architecture is reduction of storage requirements of routing information, communication overhead and computational overhead at each node. Discrete-event simulation is used for modelling and performance evaluation. Various options and variations of the protocols are examined in the…[Page 2 of abstract is missing.]Page 2 of abstract is missing

    SDN-based VANET routing: A comprehensive survey on architectures, protocols, analysis, and future challenges

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    As the automotive and telecommunication industries advance, more vehicles are becoming connected, leading to the realization of intelligent transportation systems (ITS). Vehicular ad-hoc network (VANET) supports various ITS services, including safety, convenience, and infotainment services for drivers and passengers. Generally, such services are realized through data sharing among vehicles and nearby infrastructures or vehicles over multi-hop data routing mechanisms. Vehicular data routing faces many challenges caused by vehicle dynamicity, intermittent connectivity, and diverse application requirements. Consequently, the software-defined networking (SDN) paradigm offers unique features such as programmability and flexibility to enhance vehicular network performance and management and meet the quality of services (QoS) requirements of various VANET services. Recently, VANET routing protocols have been improved using the multilevel knowledge and an up-to-date global view of traffic conditions offered by SDN technology. The primary objective of this study is to furnish comprehensive information regarding the current SDN-based VANET routing protocols, encompassing intricate details of their underlying mechanisms, forwarding algorithms, and architectural considerations. Each protocol will be thoroughly examined individually, elucidating its strengths, weaknesses, and proposed enhancements. Also, the software-defined vehicular network (SDVN) architectures are presented according to their operation modes and controlling degree. Then, the potential of SDN-based VANET is explored from the aspect of routing and the design requirements of routing protocols in SDVNs. SDVN routing algorithms are uniquely classified according to various criteria. In addition, a complete comparative analysis will be achieved to analyze the protocols regarding performance, optimization, and simulation results. Finally, the challenges and upcoming research directions for developing such protocols are widely stated here. By presenting such insights, this paper provides a comprehensive overview and inspires researchers to enhance existing protocols and explore novel solutions, thereby paving the way for innovation in this field

    A security architecture for IPv6 enabled wireless medical sensor networks.

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    We present the design of an IPv6 enabled wireless sensor network based on the IEEE 802.15.4 standard for medical monitoring. We design a routing mechanism for efficient flooding, a hop-by-hop error recovery and congestion control mechanism for reliable packet delivery and a lightweight security architecture for the medical monitoring system. We extend the widely used Extensible Authentication Protocol (EAP) to employ the Generalized Pre-shared Key (GPSK) authentication method with some optimizations for securing the system. We use the 3-party EAP model with the Personal Area Network Coordinator (PAN coordinator) of IEEE 802.15.4 standard as the EAP authenticator for authenticating sensor nodes within the radio range of the PAN coordinator. In order to use EAP authentication for a sensor node several hops away from the PAN coordinator, we define a new role (relay authenticator) for its coordinator which tunnels EAP messages to the PAN coordinator securely. We define EAP message encapsulation for IEEE 802.15.4 networks and a key hierarchy for the security architecture. We have simulated the system and shown that EAP based authentication is feasible in wireless sensor networks.The original print copy of this thesis may be available here: http://wizard.unbc.ca/record=b136235

    Overlay virtualized wireless sensor networks for application in industrial internet of things : a review

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    Abstract: In recent times, Wireless Sensor Networks (WSNs) are broadly applied in the Industrial Internet of Things (IIoT) in order to enhance the productivity and efficiency of existing and prospective manufacturing industries. In particular, an area of interest that concerns the use of WSNs in IIoT is the concept of sensor network virtualization and overlay networks. Both network virtualization and overlay networks are considered contemporary because they provide the capacity to create services and applications at the edge of existing virtual networks without changing the underlying infrastructure. This capability makes both network virtualization and overlay network services highly beneficial, particularly for the dynamic needs of IIoT based applications such as in smart industry applications, smart city, and smart home applications. Consequently, the study of both WSN virtualization and overlay networks has become highly patronized in the literature, leading to the growth and maturity of the research area. In line with this growth, this paper provides a review of the development made thus far concerning virtualized sensor networks, with emphasis on the application of overlay networks in IIoT. Principally, the process of virtualization in WSN is discussed along with its importance in IIoT applications. Different challenges in WSN are also presented along with possible solutions given by the use of virtualized WSNs. Further details are also presented concerning the use of overlay networks as the next step to supporting virtualization in shared sensor networks. Our discussion closes with an exposition of the existing challenges in the use of virtualized WSN for IIoT applications. In general, because overlay networks will be contributory to the future development and advancement of smart industrial and smart city applications, this review may be considered by researchers as a reference point for those particularly interested in the study of this growing field

    Cross-Layer Optimization of Message Broadcast in MANETs

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