Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.最新文献

{"title":"An improved XML syntax for the java programming language","authors":"M. Topolnik","doi":"10.1109/CONTEL.2005.185935","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185935","url":null,"abstract":"The benefits of using XML to encode program- ming language's source code have already been identified and XML syntaxes developed for this purpose. However, there is an absence of a systematic identification of the requirements that need to be met in order to fully leverage the potentials of XML and the key concept of the abstract syntax is being misinterpreted. Due to this the syntaxes have various deficiencies, a number of which are common to many of them. This paper clarifies the concepts, identifies these deficiencies, and proposes a new syntax for the Java programming language which avoids them. The superiority of the new syntax is demonstrated by comparing it with two of the most relevant publicly available syntaxes with the same purpose. I. INTRODUCTION The benefits of using XML to encode programming languages' source code have already been identified (1), (2) and XML syntaxes developed for this purpose (3), (4), (5). However, there is a lack of a systematic approach to the identification of more precise goals the syntax should achieve in order to fully leverage the potentials of this approach. Particularly, it appears that the central concept in the application of XML to source code, that of the abstract syntax, is not being interpreted properly. In order to explore this subject, a research project named Jezix was started. The main goal of the project was the development of an XML syntax for the Java pro- gramming language that is based on the correct treatment of the concept of the abstract syntax, which allows it to optimally leverage the identified potentials of XML. The results of the research were validated by demonstrating the proposed syntax's superiority over existing syntaxes. This was achieved by solving several code analysis prob- lems for the proposed and two of the most relevant existing syntaxes and then comparing the amount of effort needed and the properties of the resulting query code. The next section gives an overview of source code and XML. It repeats some well-known results of the formal language theory, but also clarifies important concepts and defines some terms used later. Section III presents the two key benefits of using XML for source code. Section IV reflects on the effects of using XML on the quality of the machine-to-human interface. Section V presents the most sensitive requirements the XML syntax has to meet. Section VI gives a critical overview of other existing syntaxes and identifies the common root of many of their deficiencies. Section VII briefly introduces the proposed syntax and proceeds to the presentation of the results of its comparison with the two other syntaxes. Finally, the closing section summarizes the achievements and conclusions of the Jezix project. II. OVERVIEW OF SOURCE CODE AND XML A programming language has two important compo- nents:","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"81 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121044770","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Networking policy agents: mobile, intelligent, trusted and XML-based","authors":"N. Elshiewy","doi":"10.1109/CONTEL.2005.185959","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185959","url":null,"abstract":"With policy-based networking, it is possible to define network policies based on user and application oriented business/service level objectives and to distribute the corresponding policy decisions/intelligence across the network consistently. One such policy framework is jointly defined, as an evolving industry standard, by the Internet Engineering Task Force (IETF) Working Groups (Policy Framework (PF) and Resource Allocation Protocol (RAP)) and the Directory Enabled Networks (DEN) Industry Group. Management and control, in the IETF framework, deploys a centralized client-server approach which has severe drawbacks with regard to scalability, flexibility and performance. The IETF framework does not scale well to support policy-based management of multi-domain networks. Policy rules, in the IETF framework, are static and have fixed semantics making rules difficult to adapt to change. This paper presents a new framework that overcomes these limitations. The paper describes an architecture that deploys trusted, intelligent and mobile agents in an open programmable networking framework. Policies, in the new framework, are extended to be dynamic and can be installed at network as well as at node (device) level. A policy rule is defined by a single event specification, an executable condition function and executable action function. Rules and interactions among agents are defined in XML notations and schemata. The use of XML for policy representation leads to semantically enriched policy components addressing a variety of functional requirements to a policy framework designed for an open communications market. An illustrative real-world example is also presented in the paper.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124222379","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Service management in wireless networks: technologies, products, services","authors":"J. Ghetie","doi":"10.1109/CONTEL.2005.185990","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185990","url":null,"abstract":"The tutorial provides a comprehensive analysis of wireless networking technologies with focus on service management. The wireless networking coverage includes public mobile wireless networks, wide area wireless access and metropolitan networks as well as local area-based wireless networks. Current and emerging wireless networking technologies that compose wireless networks are evaluated for their functionality and performance: PCS/PCN, MMDS, LMDS, WiMAX, and FSO solutions are analyzed for service management performance along with 802.11a/b/g wireless LAN and Bluetooth PAN solutions. The emphasis of this tutorial is on analysis and evaluation of management systems and associated service management applications used in commercial off-the-shelf products that provide service level management.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130950220","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reliable terrestrial FSO systems for higher bit rates","authors":"S. Muhammad, C. Chlestil, E. Leitgeb, M. Gebhart","doi":"10.1109/CONTEL.2005.185942","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185942","url":null,"abstract":"S ignificant advances have been made in the field of Free Space Optics (FSO) over the last few years in response to a need for greater bandwidth and improved communication systems. FSO systems are generally designed as bandwidth and protocol transparent physical layer connections. FSO has mainly evolved as the broadband wireless solution for the \"Last Mile\" connectivity gap throughout the metropolitan networks. At the Institute of Broadband Communications several FSO-systems have been developed and some newer systems are under development currently. In the previous systems, the main emphasis was on using LEDs instead of laser diodes and systems were developed for distances of about 300 ma t as pecific margin of 25 dB/km. Currently, we are developing systems that will provide data rates up-to 1 Gbps, thus providing an opportunity to fully utilize the gigabit optical backbone. Additionally, investigations are being carried out into employing better and well suited modulation and channel coding techniques to enhance the performance of the current systems. Applications of FSO besides the \"last-mile broadband access\" lie in disaster recovery, Tele-medicine, Tele-teaching and in explorations at unusual locations. Free Space Optics (FSO) is a fibreless, laser-driven technology that supports high bandwidth, with easy to install connections for the last mile access. Free Space Optics systems are starting to gain acceptance in the private market place as a solution to replace expensive fibre-optic based solutions. Optical wireless now allows service providers to cost-effectively provide optical band- width for networks, reducing Capex and Opex. Today, the modern internet users are very much inclined towards the high bandwidth demanding applications, like Video on Demand, Video Conferencing, Voice services, etc. and FSO is a well-suited technology to make the high bandwidth of the backbone (Fibre network) available to the end-user. The workgroup for Optical Communications (Optikom) at the Institute of Broadband Communications, Technical University Graz, has carried out research in the field of Free Space Optics (FSO) over a period of ten years. The work included the development of equipment for research purposes and the evaluation of commercially available FSO systems for the climate in Graz (Austria) in co-operation with industrial partners. In this paper, we present some of our earlier developed systems for short range reliable FSO links, and the uti- lization of robust, high rate LEDs in our systems instead of the more common laser diodes for developing cost effective systems. We also highlight the current work we are carrying out into the development of very high-speed Gigabit Free Space Optics Systems, to make the Gigabit backbone accessible for the end-user. An important aspect in FSO developments has always been the influence of the atmosphere and the doubts about the availability and reliability of the FSO links. We are investigating possi- bilities","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131073211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"NEMAN: a network emulator for mobile ad-hoc networks","authors":"M. Puzar, T. Plagemann","doi":"10.1109/CONTEL.2005.185841","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185841","url":null,"abstract":"Development of applications and protocols for wireless ad-hoc networks has always been a challenge. Spe- cific characteristics such as frequent topology changes due to nodes moving around, popping up or being turned off, need to be considered from the earliest stages of develop- ment. Since testing and evaluation using genuine wireless devices is both expensive and highly impractical, other tools need to be used in the development phase. Simulators give a very detailed model of lower layers' behaviors, but code often needs to be completely rewritten in order to be used on actual physical devices. Emulators present a trade-off be- tween real test beds and simulators, providing a virtual wireless network at the lowest layers, and yet allowing real code to be run on the higher layers. In this paper, we pre- sent such an emulation platform, called NEMAN, that al- lows us to run a virtual wireless network of hundreds of nodes on a single end-user machine. NEMAN has shown to be an important and very useful tool during development of different applications and protocols for our project, includ- ing a key management protocol and a distributed event noti- fication service.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"172 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114877058","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deployment of service aware access networks through IPv6","authors":"T. Stevens, K. Vlaeminck, W. Van de Meerssche, F. De Turck, B. Dhoedt, P. Demeester","doi":"10.1109/CONTEL.2005.185810","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185810","url":null,"abstract":"Substantial research effort is currently devoted to the development of a future, low-cost access and edge network, enabling the delivery of broadband multimedia services to subscribers. As the world is moving away from current ATM (Asynchronous Transfer Mode) and PPP (Point-to-Point Protocol) access network architectures for a number of reasons, including lack of Quality of service (QoS) and autoconfiguration support, this paper presents how IPv6 can fill the hole that ATM and PPP leave behind in a very convenient, packet-oriented way. The described architecture allows multiple edge nodes to be present, increasing robustness in case of edge node failure, but also increasing scalability as non-local traffic can be balanced across multiple edge nodes. The ability to process local traffic without edge involvement further increases scalability, due to the growing peer-to-peer traffic volume. Since the architecture is independent of the under- lying layer-2 technology used for the aggregation network, a phased and smooth migration from ATM to Ethernet equipment, which is claimed cheaper and easier to maintain, is possible. For some selected broadband access topologies, an efficient IPv6 subnetting scheme, minimizing routing tables through hierarchical addressing, is introduced and evaluated. Solutions for forcing non-local traffic to the correct ISP edge, in a multi-ISP environment, are presented. Finally, the deployment of the described architecture in an actual IPv6 test bed is discussed.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115928609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of connectivity information for context interpretation and derivation","authors":"Jun-Zhao Sun, J. Sauvola, J. Riekki","doi":"10.1109/CONTEL.2005.185880","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185880","url":null,"abstract":"Ubiquitous computing is the emerging new computing paradigm, of which context awareness is a key feature. In this paradigm connectivity is more than transport resource, but an important context source that can be utilized in many ways. This paper studies connectivity from the viewpoint of context awareness. Architecture for connectivity context management is proposed. Raw connectivity context including device, network, and end-end context is thoroughly defined. Methods for the derivation of high-level connectivity context are presented. The derivation is through the intelligent interpretation of raw connectivity context with the combination of other contextual information, in which knowledge-based rules are adopted. Connectivity context can also be used in the generation of other context information, in which connectivity context is employed in forms of one input factor. This paper studies three typical cases of connectivity based context derivation: location, application, and user related context.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117145496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Client based wireless LAN indoor positioning","authors":"I. Cubic, D. Begusic, T. Mandi","doi":"10.1109/CONTEL.2005.185886","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185886","url":null,"abstract":"The number of wireless users, applications and network access technologies is constantly growing. This trend supports the vision of pervasive computing where users have network access anytime and anywhere. Furthermore applications become location-sensitive and context-aware. Wireless LAN technologies are the ideal mechanism for extension of network connectivity to public places (such as airports, shopping centers, hotels, parks) and introduction of location and context-aware applications. Traditional WLAN user positioning techniques include the strongest WLAN access point and RF fingerprinting methods. In this paper an enhancement of triangulation method with RF propagation loss algorithm is proposed and compared with traditional methods. All evaluations are based on experimental results in real WLAN environment. Experimental results confirm the advantages of the proposed method.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"425 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127604322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Online distributed statistical-delay MBAC with QoS guarantees for VPLS connections","authors":"N.A. Ali, H. Mouftah, S. Gazor","doi":"10.1109/CONTEL.2005.185911","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185911","url":null,"abstract":"Real time traffic in Virtual Private Network (VPN) connections can tolerate minor violations to their end to end delay bounds. This allowed Service Providers (SP) to increase the number of admitted requests by taking advantage of the statistical multiplexing behavior of such traffic. Usually, each VPN connection has different QoS requirements such as delay and violation probability bounds. Also, each set of requirements are to be fulfilled in isolation, independently from requirements of other connections. Several Measurement Based Admission Control (MBAC) algorithms were designed to meet the soft real time services quality of service (QoS) requirements. However, intensive studies of the existing MBAC algorithms revealed that almost none of these algorithms can meet the distinct violation probability requirements of the connections. This motivated designing a novel algorithm that is capable of reserving resources to distinctly satisfy the desired violation probability and delay bounds of a connection's QoS requirements. The proposed algorithm is an online distributed algorithm. It is based on measuring the delay of the link traffic. The empirical histogram of the measured delay is fitted to a gamma distribution, which is used to calculate the required bandwidth to be reserved in order to meet the connections' QoS requirements. The simulation results for evaluating the algorithm performance show that the algorithm is capable of meeting the distinct QoS requirements of the connections while admitting two to three times the number of connections a deterministic admission control algorithm can admit.","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121327193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Energy efficiency of IEEE 802.11 DCF under non-saturation conditions","authors":"K. Sakakibara, H. Nakagawa, S. Chikada, J. Yamakita","doi":"10.1109/CONTEL.2005.185953","DOIUrl":"https://doi.org/10.1109/CONTEL.2005.185953","url":null,"abstract":"E nergy efficiency is an important issue for a mobile communication terminal which operates by a battery. Most of analytical models proposed so far for IEEE 802.11 distributed coordination function (DCF) focus on saturation performance. In this paper, we develop an analytic model to evaluate non-saturation energy consumption of IEEE 802.11 DCF, based on Bianchi's model (2). The model explicitly takes into account both the carrier sensing mechanism and an additional backoff interval after successful frame trans- mission, which can be ignored under saturation conditions. The probability generating function with respect to energy consumption for a frame to be successfully received is derived. Numerical example shows that the energy consumed in overhearing a frame destined to another user occupies the major part if the frame generation probability is greater than some critical value and if the energy required in overhearing is not negligible. If the energy consumption in overhearing can be ignored, most of the energy is wasted in receiving colliding frames. Index Terms— IEEE 802.11 DCF, energy consumption, non-saturation conditions, Markov model, equilibrium point analysis","PeriodicalId":265923,"journal":{"name":"Proceedings of the 8th International Conference on Telecommunications, 2005. ConTEL 2005.","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126895286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}