A methodological approach to BISDN signalling performance

Sophisticated signalling protocols are required to properly handle the complex multimedia, multiparty services supported by the forthcoming BISDN. The implementation feasibility of these protocols should be evaluated during their design phase, so that possible performance bottlenecks are identified and removed. In this paper we present a methodology for evaluating the performance of BISDN signalling systems under design. New performance parameters are introduced and their network-dependent values are extracted through a message flow model which has the capability to describe the impact of call and bearer control separation on the signalling performance. Signalling protocols are modelled through a modular decomposition of the seven OSI layers including the service user to three submodels. The workload model is user descriptive in the sense that it does not approximate the direct input traffic required for evaluating the performance of a layer protocol; instead, through a multi-level approach, it describes the actual implications of user signalling activity for the general signalling traffic. The signalling protocol model is derived from the global functional model of the signalling protocols and information flows using a network of queues incorporating synchronization and dependency functions. The same queueing approach is followed for the signalling transfer network which is used to define processing speed and signalling bandwidth requirements and to identify possible performance bottlenecks stemming from the realization of the related protocols

Future benefits and applications of intelligent on-board processing to VSAT services

The trends and roles of VSAT services in the year 2010 time frame are examined based on an overall network and service model for that period. An estimate of the VSAT traffic is then made and the service and general network requirements are identified. In order to accommodate these traffic needs, four satellite VSAT architectures based on the use of fixed or scanning multibeam antennas in conjunction with IF switching or onboard regeneration and baseband processing are suggested. The performance of each of these architectures is assessed and the key enabling technologies are identified

Survey of traffic control schemes and error control schemes for ATM networks

Among the techniques proposed for B-ISDN transfer mode, ATM concept is considered to be the most promising transfer technique because of its flexibility and efficiency. This paper surveys and reviews a number of topics related to ATM networks. Those topics cover congestion control, provision of multiple classes of traffic, and error control. Due to the nature of ATM networks, those issues are far more challenging than in conventional networks. Sorne of the more promising solutions to those issues are surveyed, and the corresponding results on performance are summarized. Future research problems in ATM protocol aspect are also presented

SMEs e-business behaviour: a demographics and strategic analysis

The aim of this research was to understand the strategic uses of e-business systems and technologies by classifying companies and particularly small and medium businesses according to demographics as well as e-business behavior variables.The study was based on data from a large quantitative survey of European E-business W@tch for the period 2007 using questionnaire interviews (N=409). We employed two-step cluster analysis, multinomial logistic regression and stepwise descriminant analysis as the most appropriate methods for our analysis. The findings revealed six clusters associated to e-business adoption. The six groups differ in terms of demographic characteristics as well as e-business applications they use. We found that the following clusters exist: (a) Leaders: large companies that extensively use ebusiness in a strategic manner (b) innovators: use e-business in an way that allows them to innovate and differentiate from other companies (c Beginners: small and medium companies across all sectors that only recently start to use e-business (d) Unready Adopters: micro and small companies that lag behind (e) Late Adopters: small-size companies but larger that the Unready Adopters, that appear not to be interest in the advances of ICTs and (f) Laggards: micro companies with little use of e-business.The results of our survey can positively contribute to managers aiming to take advantage of technological advances in electronic business as well as to any researcher who study e-business management and applications

Applications of satellite technology to broadband ISDN networks

Two satellite architectures for delivering broadband integrated services digital network (B-ISDN) service are evaluated. The first is assumed integral to an existing terrestrial network, and provides complementary services such as interconnects to remote nodes as well as high-rate multicast and broadcast service. The interconnects are at a 155 Mbs rate and are shown as being met with a nonregenerative multibeam satellite having 10-1.5 degree spots. The second satellite architecture focuses on providing private B-ISDN networks as well as acting as a gateway to the public network. This is conceived as being provided by a regenerative multibeam satellite with on-board ATM (asynchronous transfer mode) processing payload. With up to 800 Mbs offered, higher satellite EIRP is required. This is accomplished with 12-0.4 degree hopping beams, covering a total of 110 dwell positions. It is estimated the space segment capital cost for architecture one would be about $190M whereas the second architecture would be about$250M. The net user cost is given for a variety of scenarios, but the cost for 155 Mbs services is shown to be about $15-22/minute for 25 percent system utilization

Broadband Technologies on Residential Acces

The diffusion of broadband technologies is a hot topic for developed and many developing countries. Although the provision of service has many similar aspects, the overall and specific penetration of broadband technologies varies significantly in these countries. This study aims to examine the place of users' perceptions in the broadband issue by studying the development of the selected technologies and national policies in the light of the general information technology diffusion aspects.Diffusion of Technology, Broadband Technologies, Development of National Policies and Pricing Issues

Survey of unified approaches to integrated-service networks

The increasing demand for communication services, coupled with recent technological advances in communication media and switching techniques, has resulted in a proliferation of new and expanded services. Currently, networks are needed which can transmit voice, data, and video services in an application-independent fashion. Unified approaches employ a single switching technique across the entire network bandwidth, thus, allowing services to be switched in an application-independent manner. This paper presents a taxonomy of integrated-service networks including a look at N-ISDN, while focusing on unified approaches to integrated-service networks.The two most promising unified approaches are burst and fast packet switching. Burst switching is a circuit switching-based approach which allocates channel bandwidth to a connection only during the transmission of "bursts" of information. Fast packet switching is a packet switching-based approach which can be characterized by very high transmission rates on network links and simple, hardwired protocols which match the rapid channel speed of the network. Both approaches are being proposed as possible implementations for integrated-service networks. We survey these two approaches, and also examine the key performance issues found in fast packet switching. We then present the results of a simulation study of a fast packet switching network

Investigating e-business practices in tourism :a comparative analysis of three countries

This study examined the behaviour of tourist companies in relation to the adoption of e-business technologies and applications. The study aimed to identify groups of companies with homogenous behaviour among three European countries (Greece, Portugal and Norway). Based on data from a European survey, the study employed two-step cluster analysis which revealed 14 clusters of common behaviour (five clusters in Greece, five in Portugal and four in Norway). These clusters were named as: Leaders’ ‘Technology Experts’, ‘Fast Adopters’ ‘Beginners’, ‘Late Adopters’. In Norway, the group ‘Late Adopters’ also included companies characterised as ‘Beginners’ in the other two countries. We suggest further investigation among European countries in order to reveal more groups of similar behaviour toward e-business adoption

Communication systems supporting multimedia multi-user applications

Multimedia multi-user applications are becoming more and more important. Intensive research is underway on the design of protocols and protocol entities for future communication systems supporting multimedia multi-user applications. The development of a service description ensures that protocol designs actually produce the required functional behavior. The authors explain the approach to the description of a multimedia multi-user service. An example illustrates the use of the service description in the design of communication systems. Next, they present the basic requirements of multimedia and multi-user communications. A call model underlies and structures the service description. Finally, the authors describe the service in terms of service element