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

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

SZEROKOPASMOWE SATELITARNE SIECI DANYCH W KONTEKŚCIE DOSTĘPNYCH PROTOKOŁÓW I PLATFORM CYFROWYCH

Satellites are the transmission medium for providing connectivity and building global, continental, or regional networks around the world (satellite operators effectively use satellites to support Internet traffic), and point-to-point connections are also possible. In practical use, there are combinations of VSAT networks with terrestrial wireless extensions, allowing end users to increase the capabilities offered via satellite. This paper provides selected information on broadband satellite networks using VSAT technology, including available protocols and transmission platforms. The aim of the article is also to present the chosen technical aspects of satellite networks working with the usage of VSAT technology.Satelity stanowią medium transmisyjne dla zapewnienia łączności i budowy sieci globalnych, kontynentalnych czy regionalnych na całym świecie (operatorzy satelitarni efektywnie wykorzystują satelity do obsługi ruchu internetowego), przy czym możliwe są także połączenia typu punkt-punkt. W praktycznym użyciu są kombinacje sieci VSAT z bezprzewodowymi rozszerzeniami naziemnymi, co pozwala zwiększyć użytkownikom końcowym możliwości oferowane za pośrednictwem satelity. W artykule zamieszczono wybrane informacje na temat szerokopasmowych sieci satelitarnych z wykorzystaniem technologii VSAT, z uwzględnieniem dostępnych protokołów i platform transmisyjnych. Celem artykułu jest także przedstawienie wybranych aspektów technicznych sieci satelitarnych pracujących z wykorzystaniem technologii VSAT

Data distribution satellite

A description is given of a data distribution satellite (DDS) system. The DDS would operate in conjunction with the tracking and data relay satellite system to give ground-based users real time, two-way access to instruments in space and space-gathered data. The scope of work includes the following: (1) user requirements are derived; (2) communication scenarios are synthesized; (3) system design constraints and projected technology availability are identified; (4) DDS communications payload configuration is derived, and the satellite is designed; (5) requirements for earth terminals and network control are given; (6) system costs are estimated, both life cycle costs and user fees; and (7) technology developments are recommended, and a technology development plan is given. The most important results obtained are as follows: (1) a satellite designed for launch in 2007 is feasible and has 10 Gb/s capacity, 5.5 kW power, and 2000 kg mass; (2) DDS features include on-board baseband switching, use of Ku- and Ka-bands, multiple optical intersatellite links; and (3) system user costs are competitive with projected terrestrial communication costs

Satellite-based delivery of educational content to geographically isolated communities: A service based approach

Enabling learning for members of geographically isolated communities presents benefits in terms of promoting regional development and cost savings for governments and companies. However, notwithstanding recent advances in e-Learning, from both technological and pedagogical perspectives, there are very few, if any, recognised methodologies for user-led design of satellite-based e-learning infrastructures. In this paper, we present a methodology for designing a satellite and wireless based network infrastructure and learning services to support distance learning for such isolated communities. This methodology entails (a) the involvement of community members in the development of targeted learning services from an early stage, and (b) a service-oriented approach to learning solution deployment. Results show, that, while the technological premises of distance learning can be accommodated by hybrid satellite/wireless infrastructures,this has to be complemented with (a) high-quality audio–visual educational material, and (b) the opportunity for community members to interact with other community members either as groups (common-room oriented scenarios) or individuals (home-based scenarios), thus providing an impetus for learner engagement in both formal and informal activities

Empowering geographically isolated communities with instant access to learning and training through satellite

Enabling learning for members of geographically isolated communities such as agrarian, or maritime communities presents benefits in terms of promoting regional development and cost savings for governments and companies. We present a methodology for designing a satellite and wireless based network infrastructure and learning services to support distance learning for such isolated communities. This methodology entails (a) the involvement of community members in the development of targeted learning services from an early stage and (b) a service-oriented approach to learning solution deployment. Here this methodology is applied in the context of the European research project BASE2 (BASE2 2006), in which the following two types of geographically isolated communities are considered: agrarian and maritime

Flexibility for Internet Protocol Backbone Network for Airspace Management Agency Using Dense Wave Division Multiplexing (DWDM)

With the increasing emphasis on service quality in the network of Airspace Management Agencyin the world, coupled with the extensive growth in internet traffic globally it has become a necessity to enhance the backbone network of Airspace Agency with flexibility of Internet Protocol using the Dense Wave Division Multiplexing (DWDM). This is to enhance the backbone network with a resilience of IP-DWDM in case of failure. The IP-DWDM network merges the IP and optical layers making network flexibility possible. The measurement, analysis and evaluations of the backbone network were carried out using simulation method. The throughput, latency and data loss were evaluated and analyzed. The result obtained shows that the Dense Wave Division Multiplexing has relatively high throughput, low latency and less packet drop which resulted in high transmission rate over a long distance and low cost in running the network. The paper therefore, proposes the use of embedded flexibility of the network in achieving an increase in the efficiency and utilization of the bandwidth of the interconnecting core routers of the networks

Satellite-enabled educational services specification and requirements analysis based on user feedback

Advanced tele-education services provision in remote geographically dispersed user communities (such as agriculture and maritime), based on the specific needs and requirements of such communities, implies significant infrastructural and broadband connectivity requirements for rich media, timely and quality-assured content delivery and interactivity. The solution to broadband access anywhere is provided by satellite-enabled communication infrastructures. This paper aims to present such satellite-based infrastructures that are capable of addressing the core requirements of rich media educational services in remote areas. The paper proceeds to examine a set of services that will realise such satellite-based distance learning systems and to assess the targeted users’ interest in such services. The presented work is undertaken within the framework of the EU-funded Broadband Access Satellite Enabled Education (BASE2) project. Furthermore, requirements analysis, based on the Volere template (Robertson) and on user feedback, is undertaken