| 词条 | I-4 satellite |
| 释义 |
Three I-4 satellites make up the INMARSAT BGAN, FleetBroadband and SwiftBroadband communications network. They provide Internet and telephony connections anywhere on Earth, except the polar regions. Data servicesTwo general types of data service are currently provided:
StreamingStreaming is a guaranteed delivery style of service. A terminal requests a context of X bandwidth (currently 8, 16, 32, 64, 128, or 256kbit/s) and, if the current spot beam has enough resources available, it is allocated a guaranteed chunk of the available bandwidth. So if it asks for an 8k streaming context, the terminal will at all times be able to send data at 8kbit/s. Streaming contexts are billed by time. BackgroundBackground is a best effort style of service. Each spot beam provides a certain amount of usable bandwidth. The bandwidth which is not in use by Streaming contexts is used for Background contexts. This means that the actual amount of bandwidth you receive with a background context will vary over time. The theoretical maximum bandwidth available is ~400kbit/s. Background contexts are billed by volume. {{communications-satellite-stub}} 1 : Communications satellites |
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