Special Issue: Performance evaluation of communications in distributed systems and Web based service architectures
Article first published online: 22 SEP 2011
Copyright © 2011 John Wiley & Sons, Ltd.
Concurrency and Computation: Practice and Experience
Special Issue: Evaluation of communications in distributed systems
Volume 25, Issue 5, pages 605–607, 10 April 2013
How to Cite
Fouchal, H. and Notare, M. S. M. A. (2013), Special Issue: Performance evaluation of communications in distributed systems and Web based service architectures. Concurrency Computat.: Pract. Exper., 25: 605–607. doi: 10.1002/cpe.1811
- Issue published online: 12 MAR 2013
- Article first published online: 22 SEP 2011
Taha et al.  evaluate the consequence of choosing a frame structure type in Worldwide Interoperability for Microwave Access (WiMAX) networks based non-transparent relay stations (ntRS). In the IEEE (Institute of Electrical and Electronics Engineers) 802.16j-2009 protocol, two frame structure types are possible: single frame and multi frame. From performance evaluation point of view, a comparison has never been investigated. The authors suggest to expand on Light WiMAX ns2 add-on to support ntRS, the two frame structure types, in addition to the relevant operational requirements [e.g., quality of service (QoS)]. They show that the multi-frame structure allows higher throughput and voice capacities whereas the single frame shows some general advantage in terms of delay.
De Grandia et al.  focus on the extension of the high level architecture (HLA) standard with balancing techniques to be used during simulation. The authors studied some balancing approaches to provide a sub-optimal solution for the imbalance issues. But, these approaches are limited to some simulation aspects. Also, a hierarchical balancing scheme was proposed that presents several drawbacks that are related to the centralization of the core part of the scheme, the redistribution algorithm, which is susceptible to bottlenecks, overheads, global synchronization, and single point of failure. Therefore, a scheme based on a distributed algorithm to rearrange the computational and communication load dynamically is proposed. Experiments have been performed to evaluate the effectiveness of the distributed scheme when compared with the scheme based on a centralized redistribution algorithm. The experimental results show that the distributed balancing technique can provide balancing efficiency similar to the centralized technique or even improve the performance gain for some specific cases.
Gidenstam et al.  propose the cluster consistency model that bridges the gap between traditional and current approaches in supporting both scalability and ordered event delivery. The study introduces a dynamic and fault tolerant cluster management method that can coordinate concurrent access to resources in a peer-to-peer system and can be used to establish fault-tolerant configurable cluster consistency with predictable reliability, running on top of decentralized probabilistic protocols supporting scalable group communication. This paper provides analytical and experimental evaluation of the properties regarding the fault tolerance of the approach.
Anderson  shows that the combination of various methods for information research significantly enhance the search results. The author explores context data, using query enhancement techniques, and appropriately fusing the results to provide the best ordering when presenting the results to the user. Context data includes a users personal calendar, location, preferences, personal vocabulary, and peer recommendations. Query enhancement involves utilizing relevant contextual information to decorate a users query text to produce a more focused query. Information fusion allows the query results to be compared and re-ordered using contextual data by utilizing either a sum of products, a Bayesian technique, or a combination of the two. Finally, she has performed a case study.
Othman and Saavedra  describe IBCHWMP, a secure Hybrid-Wireless-Mesh Protocol (HWMP) using Identity Based Cryptography (IBC) over the IEEE P802.11s/D4.0 protocol. IBC has been used because it does not need to verify the authenticity of public keys. IBC mechanism has implemented to secure control messages in HWMP, namely Path Request and Path Reply. Authors focus on secure data exchange in mutable fields. Through extensive ns-3 simulations, results show that the overhead introduced by IBC-HWMP is not significant compared with the classical HWMP.
Brust et al.  present a novel and scalable approach for positioning of mobile sensor nodes with the goal of monitoring the Amazon river. The actors in the scenario are stationary and positioned at reachable spots on the land alongside the river, whereas sensor nodes are thrown into the river to collect data such as water temperature, depth, and geographical features. The actors are not equipped with positioning adaptors and they are only aware of their distances from the other actors. The sensor nodes collect data and forward it to the actors. Although floating in the river, sensor nodes are often multiple hops away from the actor nodes, which makes it challenging to apply traditional positioning techniques. Extensive simulations show that the positioning of the nodes is feasible using a multi-hop approach with local information exchange only.
Djouama et al.  are dedicated to a novel admission control for infrastructure-less clustered wireless networks. The proposed admission control is based on constraints and the lifetime duration of mobile nodes, including speed and power consumption parameters. Some new schemes are introduced, QoS parameters are negotiated during the admission procedure and a forced handover technique is developed instead of reject flows, using a centralized view of topology. The performance of the proposed scheme is analyzed and evaluated with respect to throughput and call blocking probability, using different classes of traffic. Furthermore, simulation results confirm the effectiveness of the admission control schemes.
Fouchal and Habbas  show the deployment of distributed constraint satisfaction problems (CSPs) over wireless sensor network (WSN).A distributed CSP is a Constraint Satisfaction Problem in which variables and constraints are distributed among multiple agents. On WSNs, it is usual to handle applications that need to solve distributed problems. Different real world applications can be modeled as distributed CSPs, and numerous algorithms based on on enumerative search have been proposed to solve them. One of the most well known is DistBT for Distributed Backtracking Algorithm in which, each variable is associated to each agent. This algorithm is known as a fine-grained distributed algorithm where all search efforts are based on communications between agents. This algorithm is usually very expensive. In addition, this approach is not realistic, because in general an agent might control more than one variable. For WSNs, it could not be used regarding resource constraints of these networks. In this paper, a generic methodology for developing coarse-grained distributed Backtracking Algorithm are presented. Mainly, a preprocess technique breaks a single large problem into a set of smaller connected ones. These semi-independent CSPs can be efficiently solved concurrently and can cooperate to solve the whole problem. The study illustrates the preprocess technique by the tree decomposition method for its solid theoretical properties.
Almulla et al.  propose a cryptographic protocol for symmetric key exchange based on a set of m commutative square singular matrices of dimension n×n. The suggested scheme provides a concurrent technique for users of symmetric-key cipher systems to securely exchange their private keys over public channels. This protocol is shown to possess a high level of security based on the algorithm's parameters. The paper presents a scheme for generating pseudorandom numbers form a single chaotic map for use in various applications, in particular, the suggested key exchange protocol.
Maamar et al.  propose two energy management control protocols for supplying partner selection in P2P 3D streaming that we refer to as 1L-EB and 2L-EB. Authors propose a new source load estimator that takes into account two factors namely the sources remaining energy and its number of served times. In 1L-EB, the requester uses the sources loads information to prioritize the sources in an ascending order and distribute the requests among the sources starting with the least loaded ones. Although in 2L-EB, both the requester and the supplier have important and complementary roles and participate in the energy management control. The paper reports performance evaluation obtained to evaluate our energy management control protocols using an extensive set of simulation experiments.