Results 1  10
of
58
Adaptive Approaches to Relieving Broadcast Storms in a Wireless Multihop Mobile Ad Hoc Network
 IEEE Transactions on Computers
, 2002
"... In a multihop mobile ad hoc network, broadcasting is an elementary operation to support many applications. In [15], it is shown that naively broadcasting by ooding may cause serious redundancy, contention, and collision in the network, which we refer to as the broadcast storm problem. Several thr ..."
Abstract

Cited by 103 (2 self)
 Add to MetaCart
In a multihop mobile ad hoc network, broadcasting is an elementary operation to support many applications. In [15], it is shown that naively broadcasting by ooding may cause serious redundancy, contention, and collision in the network, which we refer to as the broadcast storm problem. Several thresholdbased schemes are shown to perform better than ooding in that work. However, how to choose thresholds also poses a dilemma between reachability and eciency under dierent host densities. In this paper, we propose several adaptive schemes, which can dynamically adjust thresholds based on local connectivity information.
An extended localized algorithm for connected dominating set formation in ad hoc wireless networks
 IEEE TRANSACTIONS ON PARALLEL AND DISTRIBUTED SYSTEMS
, 2004
"... Efficient routing among a set of mobile hosts is one of the most important functions in ad hoc wireless networks. Routing based on a connected dominating set is a promising approach, where the search space for a route is reduced to the hosts in the set. A set is dominating if all the hosts in the sy ..."
Abstract

Cited by 103 (14 self)
 Add to MetaCart
Efficient routing among a set of mobile hosts is one of the most important functions in ad hoc wireless networks. Routing based on a connected dominating set is a promising approach, where the search space for a route is reduced to the hosts in the set. A set is dominating if all the hosts in the system are either in the set or neighbors of hosts in the set. The efficiency of dominatingsetbased routing mainly depends on the overhead introduced in the formation of the dominating set and the size of the dominating set. In this paper, we first review a localized formation of a connected dominating set called marking process and dominatingsetbased routing. Then, we propose a dominant pruning rule to reduce the size of the dominating set. This dominant pruning rule (called Rule k) is a generalization of two existing rules (called Rule 1 and Rule 2, respectively). We prove that the vertex set derived by applying Rule k is still a connected dominating set. Rule k is more effective in reducing the dominating set derived from the marking process than the combination of Rules 1 and 2 and, surprisingly, in a restricted implementation with local neighborhood information, Rule k has the same communication complexity and less computation complexity. Simulation results confirm that Rule k outperforms Rules 1 and 2, especially in networks with relatively high vertex degree and high percentage of unidirectional links. We also prove that an upper bound exists on the average size of the dominating set derived from Rule k in its restricted implementation.
Broadcasting in Ad Hoc Networks Based on SelfPruning
, 2003
"... We propose a general framework for broadcasting in ad hoc networks through selfpruning. The approach is based on selecting a small subset of hosts (also called nodes) to form a forward node set to carry out a broadcast process. Each node, upon receiving a broadcast packet, determines whether to for ..."
Abstract

Cited by 85 (9 self)
 Add to MetaCart
We propose a general framework for broadcasting in ad hoc networks through selfpruning. The approach is based on selecting a small subset of hosts (also called nodes) to form a forward node set to carry out a broadcast process. Each node, upon receiving a broadcast packet, determines whether to forward the packet based on two neighborhood coverage conditions proposed in this paper. These coverage conditions depend on neighbor connectivity and history of visited nodes, and in general, resort to global network information. Using local information such as khop neighborhood information, the forward node set is selected through a distributed and local pruning process. The forward node set can be constructed and maintained through either a proactive process (i.e., “uptodate”) or a reactive process (i.e., “onthefly”). Several existing broadcast algorithms can be viewed as special cases of the coverage conditions with khop neighborhood information. Simulation results show that new algorithms, which are more efficient than existing ones, can be derived from the coverage conditions, and selfpruning based on 2 or 3hop neighborhood information is relatively costeffective.
Selecting Forwarding Neighbors in Wireless Ad Hoc Networks
, 2001
"... Broadcasting is a fundamental operation which is frequent in wireless ad hoc networks. A simple broadcasting mechanism, known as flooding, is to let every node retransmit the message to all its 1hop neighbors when receiving the first copy of the message. Despite its simplicity, flooding is very in ..."
Abstract

Cited by 57 (3 self)
 Add to MetaCart
Broadcasting is a fundamental operation which is frequent in wireless ad hoc networks. A simple broadcasting mechanism, known as flooding, is to let every node retransmit the message to all its 1hop neighbors when receiving the first copy of the message. Despite its simplicity, flooding is very inefficient and can result in high redundancy, contention, and collision. One approach to reducing the redundancy is to let each node forward the message only to a small subset of 1hop neighbors that cover all of the node's 2hop neighbors. In this paper, we propose two practical heuristics for selecting the minimum number of forwarding neighbors: an O(n log n) time algorithm that selects at most 6 times more forwarding neighbors than the optimum, and an O(n²) time algorithm with an improved approximation ratio of 3, where n is the number of 1 and 2hop neighbors. The best previously known algorithm, due to Bronnimann and Goodrich [2], guarantees O(1) approximation in O(n³ log n) time.
PolynomialTime Approximation Scheme for Minimum Connected Dominating Set in Ad Hoc Wireless Networks
 Networks
"... A connected dominating set in a graph is a subset of vertices such that every vertex is either in the subset or adjacent to a vertex in the subset and the subgraph induced by the subset is connected. The minimum connected dominating set is such a vertex subset with minimum cardinality. An applicatio ..."
Abstract

Cited by 50 (10 self)
 Add to MetaCart
A connected dominating set in a graph is a subset of vertices such that every vertex is either in the subset or adjacent to a vertex in the subset and the subgraph induced by the subset is connected. The minimum connected dominating set is such a vertex subset with minimum cardinality. An application in ad hoc wireless networks requires the study of the minimum connected dominating set in unitdisk graphs. In this paper, we design (1+1=s)approximation for the minimum connected dominating set in unitdisk graphs, running in time n O((slogs) 2 )
Initializing Newly Deployed Ad Hoc and Sensor Networks
 in Proceedings of 10 th Annual International Conference on Mobile Computing and Networking (MOBICOM
, 2004
"... A newly deployed multihop radio network is unstructured and lacks a reliable and e#cient communication scheme. In this paper, we take a step towards analyzing the problems existing during the initialization phase of ad hoc and sensor networks. Particularly, we model the network as a multihop quasi ..."
Abstract

Cited by 50 (15 self)
 Add to MetaCart
A newly deployed multihop radio network is unstructured and lacks a reliable and e#cient communication scheme. In this paper, we take a step towards analyzing the problems existing during the initialization phase of ad hoc and sensor networks. Particularly, we model the network as a multihop quasi unit disk graph and allow nodes to wake up asynchronously at any time. Further, nodes do not feature a reliable collision detection mechanism, and they have only limited knowledge about the network topology. We show that even for this restricted model, a good clustering can be computed e#ciently. Our algorithm e#ciently computes an asymptotically optimal clustering. Based on this algorithm, we describe a protocol for quickly establishing synchronized sleep and listen schedule between nodes within a cluster. Additionally, we provide simulation results in a variety of settings.
Forwardnodesetbased broadcast in clustered mobile ad hoc networks
 Wireless Communication and Mobile Computing
, 2003
"... A taxonomy of broadcast protocols in mobile ad hoc networks (MANETs) is given where protocols are classified into four groups: global, quasiglobal, quasilocal, and local. The taxonomy also divides protocols based on the nature of algorithms: probabilistic and deterministic. The locality of mainten ..."
Abstract

Cited by 48 (14 self)
 Add to MetaCart
A taxonomy of broadcast protocols in mobile ad hoc networks (MANETs) is given where protocols are classified into four groups: global, quasiglobal, quasilocal, and local. The taxonomy also divides protocols based on the nature of algorithms: probabilistic and deterministic. The locality of maintenance also plays an important role in evaluating the protocol. An important objective in designing a broadcast protocol is to reduce broadcast redundancy to save scarce resources such as energy and bandwidth and to avoid the broadcast storm problem. This objective should be achieved without introducing excessive overhead and time delay, measured by the sequential rounds of information exchanges. This is done by choosing a small forward node set that forms a connected dominating set (CDS) to carry out a broadcast process. In this paper, a clustered network model is proposed in which each node is a clusterhead in the clustered architecture. Clusterheads are connected by carefully selecting nonclusterhead nodes locally at each clusterhead to connect clusterheads within 2.5 hops, a novel notion proposed in this paper. Information of neighbor clusterheads are piggybacked with the broadcast packet to further reduce each forward node set. It is shown that this approach is quasilocal with locality of maintenance. In addition, this approach has a constant approximation ratio to the minimum connected dominating set (MCDS) and generates a small forward node set in the average case. Comparisons are also done through simulation with representative protocols from each of the four groups of protocols based on the proposed taxonomy.
Topology Management in Ad Hoc Networks
, 2003
"... The efficiency of a communication network depends not only on its control protocols, but also on its topology. We propose a distributed topology management algorithm that constructs and maintains a backbone topology based on a minimal dominating set (MDS) of the network. According to this algorithm, ..."
Abstract

Cited by 45 (2 self)
 Add to MetaCart
The efficiency of a communication network depends not only on its control protocols, but also on its topology. We propose a distributed topology management algorithm that constructs and maintains a backbone topology based on a minimal dominating set (MDS) of the network. According to this algorithm, each node determines the membership in the MDS for itself and its onehop neighbors based on twohop neighbor information that is disseminated among neighboring nodes. The algorithm then ensures that the members of the MDS are connected into a connected dominating set (CDS), which can be used to form the backbone infrastructure of the communication network for such purposes as routing. The correctness of the algorithm is proven, and the efficiency is compared with other topology management heuristics using simulations. Our algorithm shows better behavior and higher stability in ad hoc networks than prior algorithms.
Distributed Dominant Pruning in Ad Hoc Networks
, 2003
"... Efficient routing among mobile hosts is an important function in ad hoc networks. Routing based on a connected dominating set is a promising approach, where the search space for a route is reduced to the hosts in the set. A set is dominating if all the hosts are either in the set or neighbors of ho ..."
Abstract

Cited by 43 (0 self)
 Add to MetaCart
Efficient routing among mobile hosts is an important function in ad hoc networks. Routing based on a connected dominating set is a promising approach, where the search space for a route is reduced to the hosts in the set. A set is dominating if all the hosts are either in the set or neighbors of hosts in the set. The efficiency of dominatingsetbased routing mainly depends on the overhead introduced in the formation of the dominating set and the size of the dominating set. In this paper, we first review a distributed formation of a connected dominating set called marking process and dominatingsetbased routing. Then we propose a dominant pruning rule to reduce the size of the dominating set. This dominant pruning rule (called Rule k) is a generalization of two existing rules (called Rules 1 and 2). We prove that the vertex set derived by applying Rule k is still a connected dominating set. When implemented with local neighborhood information, Rule k is more effective in reducing the dominating set derived from the marking process than the combination of Rules 1 and 2, and has the same communication complexity and less computation complexity. Simulation results confirm that Rule k outperforms Rules 1 and 2, especially in relatively dense networks with unidirectional links.
Implicit source routes for ondemand ad hoc network routing
 In Proceedings of the Second Symposium on Mobile Ad Hoc Networking and Computing (MobiHoc 2001
, 2001
"... In an ad hoc network, the use of source routing has many advantages, including simplicity, correctness, and flexibility. For example, all routing decisions for a packet are made by the sender of the packet, avoiding the need for uptodate routing information at intermediate nodes and allowing the r ..."
Abstract

Cited by 33 (6 self)
 Add to MetaCart
In an ad hoc network, the use of source routing has many advantages, including simplicity, correctness, and flexibility. For example, all routing decisions for a packet are made by the sender of the packet, avoiding the need for uptodate routing information at intermediate nodes and allowing the routes used to be trivially guaranteed loopfree. It is also possible for the sender to use different routes for different packets, without requiring coordination or explicit support by the intermediate nodes. In addition, ondemand source routing has performed very strongly when compared against other proposed protocol designs. However, source routing has the disadvantage of increased perpacket overhead due to the source route header that must be present in every packet originated or forwarded. In this paper, we propose and analyze the use in ad hoc networks of implicit source routing, and show that it preserves the advantages of source routing while avoiding the associated perpacket overhead in most cases. We evaluated this technique through detailed simulations of ad hoc networks based on the Dynamic Source Routing protocol (DSR), an ondemand ad hoc network routing protocol based on source routing. Although routing packet overhead increased slightly with implicit source routing, by about 12.3%, the total number of bytes of overhead decreased substantially, by between 44 and 86%. On all other metrics evaluated, the performance of DSR either did not change significantly or actually improved somewhat, due to indirect effects of the reduced routing overhead. 1.