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To improve the adaptability and stability of Dijkstra algorithm for solving routing problem of service composition, a method to solve routing problem of service composition based on an improved ant colony algorithm is proposed. Firstly, based on the traditional ant colony algorithm, the constraints of it are improved. Secondly, a problem solving model for improved ant colony algorithm is established,...
With the development of the wireless communications technology and the multimedia technology, the wireless internet multimedia transport of real-time becomes an important applications field. We will meet a problem that the distinguish of the status of package loss is not very good which will affect the QoS when we transport multimedia data in wireless internet. Based on this problem the article comes...
It is heterogeneous wireless Networks (HWN) aggregation foundation for vertical handoff (VHO), and that is key characters of core technology for multi-network aggregation. The currently mechanism handoff trigger is analyzed, a best network selected (BNS) framework is designed, the parameters of network terminal and user terminal of effecting VHO algorithm, and which also include norm of capable parameters,...
Ultra-Wide Band (UWB) wireless communication is a promising spread-spectrum technology with features of low cost, low power and high time resolution has potentially important applications in wireless ad hoc networks. This paper presents a novel quality of service (QoS) routing scheme for wireless multimedia ad hoc networks. Besides applying neighbor detection method in route discovery procedure, the...
Quality of service (QoS) provisioning generally assumes more than one QoS measure which implies that QoS routing can be categorized as an instance of routing subject to multiple constraints: delay-jitter, bandwidth, cost, etc. We study the problem of constructing multicast trees to meet the QoS requirements of real-time interactive applications where it is necessary to provide bounded delays and bounded...
Rich media application enables plenty of interactive, information-rich services to enhance end user's viewing experience. In current standards released for such service, only one rendering space is defined to handle multiple types of content belonging to the same service. However, a new trend is to assign more than one terminal device to render rich media application in a cooperative way inside a...
Unlike traditional routing schemes that route all traffic along a single path, multipath routing strategies split the traffic among several paths in order to ease congestion. It has been widely recognized that multipath routing can be fundamentally more efficient than the traditional approach of routing along single paths. aiming at the increasing network traffic and the deficity that the former Ant...
Fourth Generation Networks will invariably adopt MIMO-OFDMA techniques, in order to cope with increased data rate demands and improved Quality of Service (QoS) requirements. OFDMA is a popular multiple access candidate, since it facilitates multi-user diversity by enabling two dimensional multiple access, in time and frequency domains. Random Beamforming enables exploitation of spatial multi-user...
Due to the license-exempt nature of the cognitive radio (CR), multiple CR networks may operate (coexist) on the same channel. In this paper, we first discuss some techniques for self-coexistence of CR local and personal area networks, where the self-coexistence means the coexistence of homogeneous CR networks using the same PHY/MAC protocol. Then, we propose a self-coexistence etiquette for the ECMA...
Received video quality is dependent on the available link rate and the packet loss rate, which are inter-related in a busy network link. Even low packet loss ratios (PLRs) can significantly reduce the video quality. In this paper, a packet level parity FEC is applied to the video stream in order to reduce the video PLR. A constant gross data rate is assumed, such that adding a FEC leads to a decrease...
The IEEE 802.16 standard is a promising technology for 4G mobile networks. Though supporting versatile service classes, best effort (BE) service class is expected to dominate WiMAX networks, due to operational simplicity. One of bandwidth request mechanisms that subscriber stations (SS) can utilize to issue bandwidth requests (BW-REQ) for BE connections is contention-based random access. An SS starts...
This paper introduces a technology convergence adaptor for a previously presented Inter-MAC architecture for heterogeneous home area networks. Its main task is to translate technology-dependent link metrics into a machine readable common language. This language allows for the description of various service and application classes and provides means to describe link metrics of underlying MAC protocols...
Cognitive radio (CR) technology has been considered promising to enhance spectrum efficiency via opportunistic transmission at link level. To make CR useful, networking CRs to form a cognitive radio network (CRN) is able to support end-to-end transmission from CR source to CR destination. However, the opportunistic nature of CR link for interference avoidance to primary users degrades the quality-of-service...
3GPP has specified that terminals can be configured to use either 2 or 10 ms transmission time interval in high speed uplink packet access systems. The purpose of this paper is to evaluate the benefit of exploiting a mixture of both of the transmissions time intervals within a cell instead of only one. The study is quantified by means of studying the achievable coverage of voice over IP and possible...
Since several years, communications between fixed and mobile units have been studied in areas in underground tunnels. The leaky feeder (LF) is one of the most useful results of these studies. The LF technology in combination with other communication systems allows us to reduce the transmission power of the mobile entities without sacrificing quality of service. Because the leaky feeder cables are...
IEEE 802.15.4 defines the physical layer and medium access control sub-layer specifications for low-data-rate wireless connectivity devices with very limited battery consumption requirements typically operating in the personal operating space. Unlike traditional wireless networks, its unique characteristics, such as low-data-rate and guaranteed time slots (GTS), have brought unprecedented challenges...
Mobile ad hoc networks are self organizing multi-hop wireless networks with no fixed infrastructure. All the users in these networks are mobile. The mobiles communicate either directly or via other nodes of the network by establishing routes. The mobility of nodes causes the existing links to be break frequently. So if we can predict future movement, the resources reservation can be made before be...
Multidomain traffic engineering (TE) has the potential not only of guaranteeing the quality of service (QoS) to connections spanning multiple domains but also of effectively utilizing intradomain resources. The hierarchical Optical Internetworking Forum (OIF) External Network-to-Network Interface (E-NNI) control plane platform has emerged as a promising candidate aiming at guaranteeing multidomain...
In this paper,based on the analysis and comparison of the several current typical multiple constraints routing algorithms,a kind of simple multiple contraints multimedia routing algorithm is researched and implemented.Multiple contraints embodied in the two indicators bandwidth and latency.In this algorithm,all links not meeting the bandwidth requirements are eliminated firstly,then we select the...
SIP (Session Initiation Protocol) is standardized by Internet Engineering Task Force (IETF) as a signaling and control functionality for multimedia services (video and audio). However, SIP is a text-based protocol with messages usually exceeding several hundred bytes in size, thus causing high call set-up latency over low bit-rate links. As a consequence, SIP suffers from undesirable delay which is...
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