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Telecommunications Quality of Services: The Business of Success, 2004. QoS 2004. IEE

Date 2-3 March 2004

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Displaying Results 1 - 25 of 38
  • Integrated algorithm of HMIPv6 & MPLS for ns to support next generation wireless networks

    Publication Year: 2004 , Page(s): 156 - 159
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (237 KB)  

    The paper highlights the advantages of HMIPv6 (hierarchical Mobile IPv6) and MPLS integration in the aspect of guaranteed and efficient end-to-end QoS provision in multi-domain wireless networks. The multiple domain scenario of radio access networks is considered and we focus on traffic transmission from/to a mobile host (MH) and a correspondent node (CN). Agent advertisement, MH registration, label switched path establishment and maintenance, and data transfer procedures are described. Intra-domain and inter-domain soft handover is discussed in the context of multiple domain wireless access networks. A novel network simulator algorithm, suitable for ns2 (Kevin Fall, K.V., 2003), which integrates the functionalities of the two technologies (HMIPv6 and MPLS) is proposed and the structural parts of the block diagram are explained in detail. View full abstract»

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  • Quality differentiation and economic efficiency

    Publication Year: 2004
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (527 KB)  

    Summary form only given. The capability to differentiate quality of service is important for networks in order to improve their economic efficiency. In such a 'market-managed' network, customers can express their preferences and acquire the resources for which they are willing to pay. Prices, if set correctly, can provide the right incentives so that network resources can be used more efficiently, and hence the competitive position of the network operator can be improved. Traditional approaches to providing QoS place the network at the centre of making decisions about how to customize and differentiate services. However, end-users (devices) may benefit greatly from the ability to 'construct' their own services. This is in line with the 'end-to-end principle', in which the internal network nodes are kept simple and complexity is moved to the edges where information about user utility resides. If users can obtain greater surpluses, then the network can probably obtain more revenue. The challenge is therefore to provide the edges with flexibility to express their preferences in terms of quality and payments, while enabling the network provider to control the pricing and the provisioning process. We discuss the above concepts and provide certain microeconomic arguments that support them. View full abstract»

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  • Stochastic reward net end-to-end quality of service (QoS) simulation modeling across ATM network: using the goodput model

    Publication Year: 2004 , Page(s): 165 - 170
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (202 KB)  

    Multiservice network architecture designers the world over are adopting asynchronous transmission mode (ATM) as the backbone data transmission protocol, because of ATM's tested-ability to support very high data rates in a multi-protocol and multilayered data network. To analyse and evaluate a multiservice network's overall performance, the effective throughput model has been used extensively. We employ the concept of "goodput" which describes more stringent parameters in modeling the end-to-end QoS of a multiservice network built on an ATM network. We have also derived a mathematical model for goodput and simulated the traffic situation using the stochastic reward net model. Performance indices, such as system goodput and cell loss ratio for priority cells and tagged cells, were measured. The simulation model was subjected to different buffer size (20, 40, 60) ATM cells, while varying the ratios of probabilities of priority cells to tagged cells (0.5:0.5, 0.6:0.4, 0.7:0.3). The network performance simulation showed a system goodput measure of approximately 97%. It was also observed that priority cell loss ratios fluctuated between 0.0014 and 0.0016 which is crucial for the deployment of a rate- and delay-sensitive data communication system. View full abstract»

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  • Towards scalable end-to-end QoS provision for VoIP applications

    Publication Year: 2004 , Page(s): 132 - 135
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (293 KB)  

    The growth of the Internet and the development of its new applications have increased the demand for providing a certain level of resource assurance and service support. The concept of ensuring quality of service (QoS) has been introduced in order to provide the support and assurance for these services. Different QoS mechanisms, such as integrated services (IntServ) and differentiated services (DiffServ), have been developed and introduced to provide different levels of QoS provision. However, IntServ can suffer from scalability issues that make it infeasible for large-scale network implementations. On the other hand, the aggregated-based per-flow technique of DiffServ does not provide such an end-to-end QoS guarantee. Recently, the IETF have proposed a new QoS architecture that implements IntServ over DiffServ in order to provide an end-to-end QoS for scalable networks. Hence, it became possible to provide and support a certain level of QoS for some delay sensitive and bandwidth-demanding applications such as voice over Internet Protocol (VoIP). With regard to VoIP applications, delay, jitter and packet loss are crucial issues that have to be taken into consideration for any VoIP system design and such parameters need a distinct level of QoS support. View full abstract»

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  • A MIP-SIP macro-mobility management scheme for VoIP across wired and wireless domains

    Publication Year: 2004 , Page(s): 114 - 118
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (311 KB)  

    With the convergence of the Internet and cellular networks, voice-over-IP (VoIP) applications across wired and wireless domains are of increasing importance. Two major mobility management protocols, Mobile IP (MIP) and session initiation protocol (SIP), have been proposed to handle macro-mobility in the network layer and the application layer respectively, either independently or jointly for different scenarios. The paper explores the capabilities of MIPv6 and SIP in supporting VoIP applications from the point of view of "mobility awareness" or "mobility unawareness". It proposes a MIP-SIP hybrid mobility management architecture that enables mobile hosts running mobility-unaware applications to communicate with CHs (correspondent hosts) running mobility-aware applications. The paper focuses on. macro-mobility support across wireless and wired domains and compares the hybrid architecture with MIPv6 and SIP in terms of handoff disruption time and the user-perceived quality of service (QoS) through analysis and proof-of-concept simulations. The AAA (authentication, authorisation and accounting) functions are also considered for inter-domain handoffs. View full abstract»

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  • The IEE Telecommunications Quality of Service: the busniess of success (QoS 2004)

    Publication Year: 2004 , Page(s): 0_3
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  • IPCablecom as transport platform for interactive multimedia services in cable TV networks

    Publication Year: 2004 , Page(s): 94 - 98
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (346 KB)  

    With the introduction of cable communication systems such as DOCSIS or Euro-DOCSIS and enhancements by end-to-end platforms like IPCablecom, it became possible to transmit time-critical, IP based, multimedia services across cable TV networks. The paper introduces an architecture that exploits the functionality of IPCablecom as a transport platform, integrating it into the service environment defined by DVB-MHP (digital video broadcasting-multimedia home platform). The resulting system represents a digital platform for multimedia services. The paper details the adaptations applied to IPCablecom in order to accommodate the change in the underlying service scenario. Special focus is given to quality of service (QoS) and signalling aspects. Furthermore, the paper describes a simulation model which allows the performance of the specified transport platform to be analysed and the functionality of the platform's architecture to be verified. View full abstract»

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  • The 4th generation conjointed network 'all-optical' path routed communication networks: foundation for a 4G broadband mobile network

    Publication Year: 2004 , Page(s): 32 - 36
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  • Copyright

    Publication Year: 2004 , Page(s): 0_4
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  • Quality of service in TCP/IP networks: a DiffServ testbed

    Publication Year: 2004 , Page(s): 141 - 145
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (320 KB)  

    An implementation of the weighted fair queue algorithm on a Pentium/Windows 2000 platform is presented with preliminary test results. This is part of a DiffServ testbed being developed at the University of Greenwich for evaluating various design options relating to the provision of quality of service over the Internet. The present implementation includes: (a) a packet classifier which assigns incoming packets to different queues based on the ToS field in the IP header; (b) packet queues with finite buffers; (c) a scheduler which implements the WFQ algorithm. Preliminary results include queuing delays and loss probabilities for different packet arrival rates, service weights and buffer size. View full abstract»

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  • Analysis of a quality of service algorithm for wide-area private mobile radio systems

    Publication Year: 2004 , Page(s): 171 - 174
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (256 KB)  

    The paper concerns the analysis of an algorithm used for assigning frequencies to non-cellular non-trunked private mobile radio (PMR) systems. The PMR assignment algorithm was first put forward by D.F. Bacon (see Proc. IEE Conf. on Getting the Most Out of the Radio Spectrum, 2002). The authors have applied this algorithm to practical data and analysed the resulting radio spectrum into which the private mobile radio users are assigned. The assignment comparisons have been made for least and most constrained methods of frequency assignment in both virgin spectra and already congested bands. These results demonstrate the practical utility of Bacon's algorithm in improving the quality of service for all users. View full abstract»

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  • Control theory approach for implementation of dynamic pricing in mobile cellular networks

    Publication Year: 2004 , Page(s): 160 - 164
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (283 KB)  

    Accurate forecasting of future demand for cellular services is essential, as, due to the high infrastructure implementation costs involved, overestimation of demand could be very costly. In addition, the difference between peak and off-peak demand for wireless services can be very significant, both temporally and spatially, and gearing the network to meet peak demand would result in under-utilised network capacity most of the time. It has been suggested that real-time or dynamic pricing (the variation of tariff according to system utilisation) could provide an additional strategy for encouraging more efficient use of available resources. The article tests the effectiveness of a linear dynamic pricing function for QoS and revenue management. An algorithm for determining the optimal linear pricing function, taking into account the service operator's preference for revenue attainment or optimal level of QoS, is suggested; simulation results are derived using OPNET. These show that the linear dynamic pricing function, despite being intuitively easy to understand and implement, is not effective in the control of a complex cellular system. The attained revenue is consistently below the desired level, while call blocking is above the set limit. The results are independent of the assumed elasticity of demand. It is concluded that the assumption of linearity for the dynamic pricing function is the main factor for its constant underperformance and it is recommended that this assumption is dropped in the future. View full abstract»

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  • Improvement of voice qualities and network coverage for GSM handsets

    Publication Year: 2004 , Page(s): 146 - 150
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (334 KB)  

    Global system for mobile communication (GSM) is a second-generation system and the world's first mobile system to specify digital modulation and network level architectures and services. The paper represents improvements obtained from analysis of the GSM communication network, architecture of the specialized environment, and descriptions of GSM handset voice qualities and coverage areas. The way to improve voice qualities and coverage areas for GSM handsets is to arrange a suitable network coverage; analysis of the speech coding is a very important method for improvement of communication services (Macario, R.C.V., Personal & Mobile Radio Systems, p.29-31, 2000). The GSM system operates in a discontinuous transmission (DTX) mode that deduces instantaneous radio interference. A comfort noise subsystem (CNS) introduces a background acoustic noise to compensate for the annoying switched muting that occurs due to DTX. The effective results appear to mobile users when they are communicating with each other. The improvement is perfect to the voice qualities and network coverage in order to produce an excellent mobile handset. View full abstract»

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  • The quality of service - from a philosophical perspective

    Publication Year: 2004 , Page(s): 119 - 126
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    The importance of the service that you provide to society carries with it an equally vital responsibility. While not all are in a position to directly control the policies and executive level decisions of organisations, you can make a very important contribution through your individual example. This begins with the realisation of the impact that your decisions and actions have on fellow employees, customers, suppliers and eventually the nation. Knowledge, according to Plato, arises in the moment to one who is truly present. Real knowledge, as opposed to information, is not solely based on past experience, but it arises in the moment to suit the very unique need of the present. Thus the requirement for great care and attention. Despite the immense influence of communications systems on our life today, they are and will remain instruments, tools that can be used or abused. The choice is ours. The new expanding world of telecommunications does not call for a new ethic t calls for the application of unchanging principles to the new circumstances. This is how practical philosophy works. I do not have any specific recommendations for improving the quality of telecommunications service. All I can offer is a suggestion that if we remind ourselves of our full responsibilities to our self, families, company and society; if we look afresh with care and attention at the needs of those we are serving and if we test whether the service is being provided without compromising our honour and integrity or that of our company or nation, then I believe that the service you provide will be of the highest quality. View full abstract»

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  • A new VoIP adaptive playout algorithm

    Publication Year: 2004 , Page(s): 99 - 103
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (224 KB)  

    A novel playout algorithm for VoIP applications is presented. The playout times of voice packets are calculated using adaptive estimation of network delays. In contrast to previous solutions, the weighting factor that controls the estimation process is dynamically adjusted according to the observed delay variations. This results in higher-quality estimates of network delays. With this algorithm, the trade-off between buffering delay and late packet loss at the receiver is significantly improved. Experimental results show that the new algorithm can achieve higher subjective call quality than the basic adaptive algorithm, as measured by the ITU-T E-model methodology. View full abstract»

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  • Defining and monitoring QOS metrics in the next generation wireless networks

    Publication Year: 2004 , Page(s): 37 - 42
    Cited by:  Papers (2)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (325 KB)  

    Defining and monitoring QoS metrics for service level agreements (SLA) in next generation wireless networks is a challenging task for a service provider. Some complex issues that need to be addressed are: different QoS requirements for different classes of applications; support of real-time applications (such as voice, video) over packet based networks; heterogeneous characteristics of wireless and wireline networks; mobility of users; evolving applications; services; etc. Existing SLAs and their monitoring methodologies and tools lack the sophistication required to address these new issues. This work provides a framework to address them. It classifies next generation applications into several classes and identifies the important QoS metrics for each class. It provides the measurement methodologies for these QoS metrics so that a service provider may establish and verify a service level agreements with his/her customers. It identifies the requirements for the tools in order to monitor/measure these new QoS metrics. Finally, it discusses the challenges faced by service providers while implementing these recommendations. View full abstract»

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  • A legacy of echo and silence

    Publication Year: 2004 , Page(s): 109 - 113
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (285 KB)  

    The paper discusses voice transmission quality issues relating to interworking between VoIP and PSTN "legacy" networks. The evolution of voice quality with technological progress in the PSTN from its inception to the present day VoIP systems is described and this sets the scene for discussion of echo control and silence removal in case study examples. View full abstract»

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  • Setting the standard - QoS in ITU-T and ETSI

    Publication Year: 2004 , Page(s): 1 - 16
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  • QoS attributes for packet switched services in 3rd generation mobile systems (UMTS)

    Publication Year: 2004 , Page(s): 52 - 58
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    The third generation of mobile systems (UMTS) is intended to provide different end user data applications based on packet switched services. In order to meet end users' expectations and to overcome the limitation of system resources and the air interface capacity, it is necessary to define quality of service (QoS) attributes properly. We give an overview of UMTS services, list QoS attributes used for packet switched services and explain how they are defined to provide and maintain quality of service requirements for various types of connections in a packet switched mobile environment. Considerations are mainly based on the technical characteristics and realizations of the W-CDMA standards, which have been proposed by the 3GPP organisation, and, as such, accepted for implementation in UMTS mobile systems. View full abstract»

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  • So you think you can measure IP QoS?

    Publication Year: 2004 , Page(s): 151 - 155
    Cited by:  Papers (1)
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (290 KB)  

    For broadband networking to be a commercial success, operators need to provide differentiated levels of quality of service (QoS). Networks are shared infrastructures of buffering and bandwidth resources, and are designed to bound the delays and losses inherent in packet queueing technology. But can customers be sure they are getting the QoS they are paying for? It is thought that active probing gives customers the ability to check that their service level agreements are being honoured, because it mimics "what the customer experiences". This may be an illusion. We investigate the trade-off between accuracy of QoS measurement and packet probing overhead. We show that, under realistic networking scenarios, measurement accuracy could be poor, giving little real indication of user experience. Our results demonstrate that the rate, size, and phasing of active probes must be carefully considered. Hence it is vital that measurement devices are configured appropriately for the networking and customer traffic scenarios. View full abstract»

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    Publication Year: 2004 , Page(s): 0_2
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  • Traffic dimensioning for GSM-over-IP services

    Publication Year: 2004 , Page(s): 136 - 140
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    The cost of the link connecting the backbone network and customer premises has a major effect on the uptake of IP-based wireless office technology. The paper describes the factors influencing the dimensioning of this link, by taking into consideration a system which uses the IP network in order to deliver voice and signalling to a GSM radio access system. Through simulation, it is shown that discontinuous transmission for the voice traffic offers a reduction in the bandwidth requirements, and makes the system more resilient to short periods of congestion. The results presented can be employed in order to dimension link requirements for GSM-over-IP services. View full abstract»

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    Publication Year: 2004 , Page(s): 185
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  • IP/MPLS network performance and QoS. Part 1: Performance metrics efinitions and practical usage

    Publication Year: 2004 , Page(s): 74 - 85
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    The paper focuses on network performance management through active measurement. It looks at the reference path and terminology used. IP parameters and metrics are summarised and compared. Metric development in-progress is discussed. There are new challenges in performance measurement for MPLS-enabled IP networks because of new network protocols and a new class of failures. Detection of this new class of failures requires active measurement implementations such as ping for connectivity and dedicated measurement systems. Practical implementations are considered from the point of view of service providers, customers, and third parties. The paper gives the IP measurement design with which AT&T continuously measures its IP network as part of QoS assurance. View full abstract»

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  • IP network performance and QoS: signaling and interworking issues

    Publication Year: 2004 , Page(s): 86 - 93
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    In 2000, the IAB's RFC 2990, "Next Steps for the IP QoS Architecture", compared IntServ and DiffServ style networks and considered broader architectural approaches/requirements, including: critical "gaps" in routing; resource management; monitoring and accounting; application and service development; incremental, heterogeneous deployment. Therefore, what is needed is "a set of QoS mechanisms and a number of ways these mechanisms can be configured to interoperate in a stable and consistent fashion". The paper considers the present state of end-to-end (E2E) IP QoS and progress still to be made. Y.1541 specs exist for NI-to-NI (network interface) IP QoS classes, but there is no widely accepted delivery mechanism yet. It is still unclear if QoS-related resource control of others' networks will ever be allowed; even if some carriers agree, interoperability is still an issue. Over-provisioning is still central to many solutions. No forum is yet addressing reliability and restoration mechanisms for E2E IP QoS in any tangible way. Recent attention on IP emergency communications have served as a magnet for all of the shortcomings of E2E QoS proposals in IP space (IETF's IEPREP). View full abstract»

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