Current Issue : April - June Volume : 2015 Issue Number : 2 Articles : 5 Articles
Power line communications (PLCs) refer to a technology based on the existing electrical wiring to transmit data among the devices\nconnected to the network. The PLC technology is an excellent solution widely studied and analysed by researchers, even in those\nareas characterized by strict requirements, such as industries. In this paper, a technique based on fuzzy logic, for the dynamic\nmanagement of the amplitude of the signal emitted by the devices of a power line network, is proposed.Themain aim is to manage\nthe amplitude of the transmission signal in order to reduce the noise introduced into the network, and, as a consequence, the\npower consumption, increasing data transmission quality of network in terms of Quality of Service (QoS). This solution has been\nimplemented into embedded systems based on the ADD1010, a power line System on Chip (SoC), and tested through a real scenario\nrealized in laboratory....
The Session Initiation Protocol (SIP) is an application layer signaling protocol used to create, manage, and terminate sessions in an\nIP based network. SIP is considered as a transactional protocol. There are two main SIP transactions, the INVITE transaction and\nthe non-INVITE transaction.The SIP INVITE transaction specification is described in an informal way in Request for Comments\n(RFC) 3261 and modified in RFC 6026. In this paper we focus on the INVITE transaction of SIP, over reliable and unreliable\ntransportmediums, which is used to initiate a session. In order to ensure the correctness of SIP, the INVITE transaction is modeled\nand verified using event-B method and its Rodin platform. The Event-B refinement concept allows an incremental development\nby defining the studied system at different levels of abstraction, and Rodin discharges almost all proof obligations at each level.\nThis interaction between modeling and proving reduces the complexity and helps in assuring that the INVITE transaction SIP\nspecification is correct, unambiguous, and easy to understand....
Thepaper deals with constraint-based routing (CBR) in MPLS-TE networks and proposes a newCBRalgorithmbased on fuzzy logic\ncalled Fuzzy Class-Based Algorithm (FCBA).Multiprotocol label switching with traffic engineering (MPLS-TE) networks represent\na popularmechanism to effectively use resources of service providers� core networks.Thepaths can be either built by administrators\n(explicit routing) or built by using existing routing algorithms which mostly decide based on the shortest paths towards the\ndestination which might not be sufficient in nowadays� multimedia networks. To address this problem various CBR algorithms\nhave emerged which take into consideration various aspects important to existing traffic like QoS parameters or administrative\npolicies. FCBAmakes routing decisions based on traffic classes and by using fuzzy logic we can assign normalized values to various\nconstraints based on the traffic class� preferences (e.g., low delay paths for voice traffic) and network administrator�s preferences\n(e.g., avoiding congested links). The paper provides comparison of FCBA with existing CBR approaches based on their ability to\nprovide QoS parameters loss.The simulations show that FCBA provides the best results for the highest priority traffic where it uses\nlower priority traffic to efficiently utilize the network....
A compact CPW-fed triband slot antenna for WLAN/WiMAX applications is proposed. The proposed antenna is formed by an\nasymmetric ring, an inverted L-strip, and a straight strip. By employing these structures, the antenna can generate three operation\nbands with compact size and simple structure. The measured and simulated results show the presented antenna has impedance\nbandwidths of 100MHz (2.39ââ?¬â??2.49GHz), 360MHz (3.36ââ?¬â??3.72GHz), and 760MHz (5.13ââ?¬â??5.89GHz), which covers both WLAN\nin the 2.4/5.2GHz bands and WiMAX in the 3.5/5.5GHz bands. The antenna is successfully simulated and measured, showing\ntriple bands can be obtained by using three different radiators and also indicating that the proposed antenna is suitable for the\nWiMAX/WLAN applications...
Mobile ad hoc networks are noncentralised, multihop, wireless networks that lack a common infrastructure and hence require\nself-organisation. Their infrastructureless and dynamic nature entails the implementation of a new set of networking technologies\nin order to provide efficient end-to-end communication according to the principles of the standard TCP/IP suite. Routing, IP\naddress autoconfiguration andWeb service discovery are among the most challenging tasks in the ad hoc network domain. Swarm\nintelligence is a relatively new approach to problem solving that takes inspiration from the social behaviours of insects, such\nas ants and bees. Self-organization, decentralization, adaptivity, robustness, and scalability make swarm intelligence a successful\ndesign paradigm for the above-mentioned problems. In this paper we propose BeeAdHocServiceDiscovery, a new service discovery\nalgorithm based on the bee metaphor, which also takes into account quality metrics estimates. The protocol has been specifically\ndesigned to work in mobile ad hoc network scenarios operating with Beeadhoc, a well-known routing algorithm inspired by nature.\nWe present both the protocol strategy and the formal evaluation of the discovery overhead and route optimality metrics showing\nthat BeeAdHocServiceDiscovery guarantees valuable performances even in large scale ad hoc wireless networks. Eventually, future\nresearch suggestions are sketched....
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