5. Satellite Communication Concept Note : HPA – High Power Amplifier (Earth station equipment that amplifies the transmit RF signal. ) CPE – customer premises equipment ( eg. Telephone, PABX, Ethernet hub, host server, etc.) Transmitting Earth Station Receiving Earth Station Uplink 6 GHz Downlink 4 GHz HPA Up Converter Satellite Modem CPE PSTN LNA Down Converter Satellite Modem CPE PSTN C Band – 6/4GHz Ku Band -14/12GHz Ka Band – 30/20GHz
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10. Type of VSAT technology TDMA Time-division Multiple Access FDMA Frequency Division Multiple Access SCDC Single-carrier per Channel VSAT TECHNOLOGY DAMA Demand Assigned Multiple Access CDMA Code Division Multiple Access PAMA Pre-Assigned Multiple Access FDMA
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12. TDMA (time-division multiple access) The VSAT Hub communicates with all dispersed VSATs (typically a 1.8-meter diameter parabolic-shaped dish) on an outgoing channel of up to 512kbps based on the TDM scheme. The incoming or return channel from the dispersed VSATs uses the TDMA channel technology that enables a large number of the respective VSATs to share this single return channel. The incoming routes typically operate at 128kbps, and can go up to a maximum bandwidth of 256kbps. Copyright Maxis
13. TDMA (time-division multiple access) Petrol stations, information providers, retail chains, financial institutions and any large corporation that requires transfers of low to medium rate data applications between its head office and, local and outstation branch offices. Example of Point of Sales (POS transactions), Credit Card Verification, Reservations Systems Financial and Banking applications (teller, loans, ATM) etc. Copyright Maxis
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15. SCDC (single-carrier per channel) In the Hub-to-Remote configuration, one end of the VSAT link (normally the customer's HQ) is connected to the 11-meter VSAT Hub (Earth Station) via a terrestrial leased line. A VSAT antenna at the remote end or the distant end (normally the branch office) of the VSAT link is then interconnected to the VSAT hub via the satellite. Copyright Maxis
16. SCDC (single-carrier per channel) VSAT links with a Remote-to-Remote configuration bypass the VSAT Hub and has a stand-alone VSAT antenna at both ends of the link. Typical VSAT antenna size ranges from 1.8m to 2.4m. Copyright Maxis