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VSAT Networks: Second Edition covers all the important issues involved with the installation of VSAT systems.
Since the first edition was published, the VSAT market has continued to expand steadily. VSAT technologies have advanced, prompting an increase in the take-up of VSAT services.
Offering a comprehensive introduction to the topic followed by a detailed exploration of multiple access protocols, delay analysis and system dimensioning, this edition is a highly relevant update of VSAT Networks. Written by a well respected and established member of the satellite community, it will be welcomed be academics and engineers alike.
- Covers important issues of services, economics and regulatory aspects
- Provides a detailed technical insight on networking and radio frequency link aspects, therefore addressing the specific features of VSAT networks at the three lower layers of the OSI Reference Layer Model for data communications
- This timely second edition is fully updated with new figures, improvements and revised chapter on future developments
This book will appeal to students of telecommunications, electronics and computer science. Practising telecommunications engineers and technical managers involved in the planning, design and operation of VSAT networks and systems will also find this book a valuable reference source.
selected upon the minimum required values of the EIRP and G/T which allow the requested link performance. Third, a check of all station pointing angles (azimuth and elevation) should be performed for all planned sites in such a way that no obstacles prevent the earth station from accessing the satellite, once installed. Finally, the selection procedure includes negotiations related to regulatory and ﬁnancial matters. Table 2.2 indicates typical values of EIRP and G/T for geostationary satellites,
THE CUSTOMER’S CONCERNS A VSAT network most often replaces an existing leased line data network. The reasons for using VSAT services are, in order: cost savings, ﬂexibility, reliability, data rates supported and no other services meet needs. This section attempts to list some aspects to be looked at when considering VSAT technology. 86 3.2.1 OPERATIONAL ASPECTS Interfaces to end equipment The indoor unit (IDU) is the part of the network most visible to the user, as it is most often
VSAT station as a back-up to the failed one. Some systems provide as an option automatic dial-up in case of short term outage for rerouteing of the ongoing connection to the diverse VSAT, via a terrestrial network which will route data from the failed VSAT to the hub station. Service is automatically restored when the failed VSAT is returned to service. Sun transit Sun transit occurs when the conjunction of the satellite and the sun is effective at the site of the earth station. Then the sun
indicating regions where the radiation may exceed 10 Wm−2 (= 1 mWcm−2 ). 18.104.22.168 Protection of hardware against ill-intentioned people Fences are a solution (see Figure 3.3), but it is safer if the outdoor equipment is not easily accessible, although this renders maintenance more difﬁcult. 3.2.13 Cost The cost of a VSAT per month per site has been shown to be dependent on the number of VSATs in the network (see Chapter 1, section 1.8), and the cost of the space segment is a sensitive issue.
receiving equipment (K−1 ) ﬁgure of merit of earth station receiving equipment (K−1 ) maximum value of (G/T)ES ﬁgure of merit of satellite receiving equipment (K−1 ) H total number of bits in the frame header (and trailer if any) i Ix orbit inclination received cross polar interference on X-polarisation (W) input back-off input back-off for inbound carrier input back-off for outbound carrier input back-off per carrier with multicarrier operation mode total input back-off with multicarrier