Low Message Cost Research Articles

QoS Routing Protocol Based on Resource Optimization for Aerospace Networks

To guarantee the QoS of the various traffics and take good advantage of the network resource, the QoS routing protocol based on resource optimization is proposed. By the network state information dynamic update and the QoS routing optimization model design, the QoS routing protocol can provide the optimal path for real-time traffic, broadband traffic and best effort traffic in time with low control message cost. Simulation shown that, compared to the traditional shortest path routing, the QoS routing can satisfy the demand of traffics and can improve the network performance.

EMBA: An Efficient Multihop Broadcast Protocol for Asynchronous Duty-Cycled Wireless Sensor Networks

In this paper, we propose an efficient multihop broadcast protocol for asynchronous duty-cycled wireless sensor networks (EMBA) where each node independently wakes up according to its own schedule. EMBA adopts two techniques of the forwarder's guidance and the overhearing of broadcast messages and ACKs. A node transmits broadcast messages with guidance to neighbor nodes. The guidance presents how the node forwards the broadcast message to neighbor nodes by using unicast transmissions. This technique significantly reduces redundant transmissions and collisions. The overhearing of broadcast messages and ACKs helps to reduce the number of transmissions, thus it minimizes the active time of nodes. We implement EMBA and conventional protocols of ADB and RI-MAC broadcast in ns-2 simulator to compare their performance. The simulation results show that EMBA outperforms ADB and RI-MAC broadcast in both sparse and dense networks. EMBA achieves lower message cost than the conventional protocols and significantly improves the energy efficiency in terms of both duty cycle and energy consumption.

PercolationNET: A multi-tree P2P overlay network supporting high coverage search

Flooding with a time-to-live constraint is a popular algorithm in unstructured peer-to-peer (P2P) networks. However, blind flooding may cause a large amount of network traffic. Moreover, it cannot guarantee acquiring all required data objects, especially for rare ones. To mitigate these problems, this paper proposes PercolationNET, a multi-tree sub-overlay, which is built on top of an existing P2P overlay (named original overlay). PercolationNET organises peers in a tree-based structure which facilitates reliable and efficient message dissemination for search. The search process is divided into two stages. A query message is first propagated on the original overlay, and then broadcast along the sub-overlay PercolationNET. PercolationNET combines the advantages of fast coverage speed in flooding-based scheme and low traffic cost in tree-based scheme. The experimental results of PercolationNET compared with FloodNet confirm the superiority of PercolationNET in achieving faster coverage speed and lower message cost.

General Tree k-Coteries to Reduce the Degradation of Quorums

k-Coterie is a useful concept to solve the distributed k-mutual exclusion problem. The distributed k-mutual exclusion algorithms based on k-coteries have benefits of the high fault-tolerance and the low message cost. Harada and Yamashita proposed a basic tree structure to construct tree k-coteries. When the root fails, quorums are degraded and their sizes grow rapidly. In this paper, we propose the general tree structure to construct general tree 1-coteries to reduce the degradation of quorums. In the general tree 1-coterie, the responsibility of the root to construct small quorums could be adjusted. When the root fails, the degradation of quorums could be reduced. Then, we propose the coterie root-join operation to construct general tree k-coteries by root-joining k general tree 1-coteries at a common root. In the general tree k-coterie, the degradation of quorums and the quorum size could be reduced at same time. We show that general tree k-coteries could be complemental. Thus, general tree k-coteries are resilient when the network is 2-partitioned.

Emergency guiding and monitoring applications in indoor 3D environments by wireless sensor networks

Recently, Wireless Sensor Networks (WSNs) have been widely discussed in many applications. In this paper, we propose a novel Three-Dimensional (3D) emergency service that aims to guide people to safe places when emergencies happen. At normal time, the network is responsible for monitoring the environment. When emergency events are detected, the network can adaptively modify its topology to ensure transportation reliability, quickly identify hazardous regions that should be avoided and find safe navigation paths that can lead people to exits. In particular, the structures of Three-Dimensional buildings are taken into account in our design. Simulation results shows that our protocols can adapt emergencies quickly at low message cost and can find safer paths to exits than existing results

A simple scheme to construct k‐arbiters with uniform quorum sizes

k‐Arbiter is a useful concept for solving the distributed h‐out of‐k mutual exclusion problem. The distributed h‐out of‐k mutual exclusion algorithms based on k‐arbiter have the benefits of high fault‐tolerance and low message cost. However, according to the definition of k‐arbiter, it is required to have a non‐empty intersection among any (k+1) quorums in a k‐arbiter. Consequently, constructing k‐arbiters is difficult. In this paper, we propose a simple scheme to construct k‐arbiters for any integer k. The constructed k‐arbiters, named binomial(q, k)‐arbiters, are uniform: each quorum in a k‐arbiter has the same size and each node contains the same number of quorums. Also, the constructed k‐arbiters perform better than other known k‐arbiters do on quorum size and availability.

Composite k-arbiters

The k-arbiter is a useful concept to solve the distributed h-out-of-k mutual exclusion problem. The distributed h-out-of-k mutual exclusion algorithms, based on the k-arbiter, have the benefits of high fault tolerance and low message cost. However, according to the definition of the k-arbiter, it is required to have a nonempty intersection among any (/spl kappa/ + 1) quorums in a k-arbiter. Consequently, constructing k-arbiters is difficult. The coterie join operation proposed by Neilsen and Mizuno (1992) produces a new and larger coterie by joining known coteries. By extending the coterie join operation, we first propose a k-arbiter join operation to construct a new and larger k-arbiter from known k-arbiters for a large system. Then, we derive a necessary and sufficient condition for the k-arbiter join operation to construct a nondominated joined k-arbiter. Moreover, we discuss availability properties of the joined k-arbiters. We observe that, by selecting proper k-arbiters, the joined k-arbiter can provide a higher availability than that of the original input. Finally, we propose a k-arbiter compound, operation to construct k-arbiters by using coteries and/or k-coteries. By that way, the problem of constructing k-arbiters can be reduced to the problem of constructing coteries and/or k-coteries.

The column protocol: A high availability and low message cost solution for managing replicated data

This paper presents a quorum-based replica control protocol which is resilient to network partitioning. In the best case, the protocol generates quorums of a constant size. When some replicas are inaccessible, the quorum size increases gradually and may be as large as O( n), where n is the number of replicas. However, the expected quorum size is shown to remain constant as n grows. This is a desirable property since the message cost for accessing replicated data is directly proportional to the quorum size. Moreover, the availability of the protocol is shown to be comparably high. With the two properties—constant expected quorum size and comparably high availability—the protocol is thus practical for managing replicated data.

Information integration and synchronization in distributed sensor networks

The computational, i.e. architectural, algorithmic, and synchronization, issues related to competitive information integration in a distributed sensor network (DSN) are addressed. The proposed DSN architecture consists of a set of binary trees whose roots are fully connected. Each node of the tree has a processing element and one or more sensors associated with it. The information from each of the sensors has to be integrated in such a manner that the communication costs are low and that the real time needs are met. An information integration algorithm that has a low message cost (linear in the number of nodes of the network) and a low distributed computation cost is presented. The problems associated with synchronizing information to be integrated in the presence of imperfect clocks is considered. The fault tolerant features of the network and the integration algorithm are discussed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>