Broadband Global Area Network
The Broadband Global Area Network (BGAN) is a global Satellite Internet Network with telephony using portable terminals. The terminals are normally used to connect a laptop computer to broadband Internet in remote locations, although as long as line-of-sight to the satellite exists, the terminal can be used anywhere. The value of BGAN terminals is that unlike other satellite Internet services which require bulky and heavy satellite dishes to connect, a BGAN terminal is about the size of a laptop and thus can be carried easily. The network is provided by Inmarsat and uses three geostationary satellites called I-4 to provide almost global coverage.[1]
Contents |
[edit] Details
Downlink speeds of high-end BGAN terminals are up to 492 kbit/s and upload speeds are also up to 492 kbit/s - Best Effort as BGAN Background IP (BIP) is a contended (shared) channel. As with all geosynchronous satellite connections, latency is an issue. Common latency is 1–1.5 seconds round trip for the Background IP service. It is slightly better for the Streaming services at 800 ms – 1 second. This latency is mainly due to the great distance that has to be traveled before a packet can reach the Internet, but is slightly exacerbated by the back-end technology as normal latency over a VSAT system is roughly 550ms. BGAN users frequently use PEP software or other TCP packet accelerators to improve performance.
BGAN terminals are made by multiple manufacturers. They all have similar capabilities. The main two that apply to basic BGAN usage are the Standard Background IP (Internet) and Telephone Voice. Data costs from the many ISPs that offer BGAN service averages about US$7.50 per Background Megabyte. Voice calling is on average US$1 per min and varies slightly based on the destination of the call (Land lines, Cell phones, other Satellite phones which are the most expensive).
BGAN is currently the fastest global data link available via a portable terminal. It can be easily set up by anyone, and has excellent voice calling quality. It works on the L band, avoiding rain fade and other issues of traditional larger satellite systems.
[edit] Signal acquisition
The actual process of connecting a BGAN terminal to the satellite is fairly straight forward. The terminal needs a line-of-sight to the geostationary satellite so a user would normally be outside, and have a general idea of what direction the satellite would be (with a compass if necessary). Turning the terminal slowly by hand, it will give some indication when the satellite is found. Then usually with the touch of one button, the terminal auto-negotiates with the satellite and connects. The average pointing time for a BGAN unit is 2 minutes, under a minute with an experienced user and a good signal. BGAN is being used in the world today for disaster response, telemedicine, business continuity, military use, and recreational use.
[edit] Terminals
Terminal manufactures are Thrane & Thrane, EMS Technologies, Hughes Network Systems,[2] and Addvalue. Terminal cost is between US$1800 and US$5000 varying based on class and capabilities of the various systems. Depending on terminal type users can connect their computers via USB, Bluetooth, WiFi, or Ethernet connection(s). This allows them to access the Internet, check e-mail, download files, or any other Internet activity they might do at a home or office. Many come equipped with a regular RJ11 Phone Jack for making PSTN calls, using an ordinary telephone handset, and many terminals have an ISDN connection to do ISDN phone calls. Some BGAN terminals have both so users can make either type of phone call. Users can also send faxes or SMS text messages. Most BGAN terminals can support a router or switch device so users can plug in multiple computers or even VOIP phones and set up a mobile office.
[edit] Coverage and availability
The BGAN service is accessible globally, excluding the poles.[3] Click on the external link below titled "BGAN Coverage - Inmarsat" for an accurate coverage map of the BGAN service.
[edit] Variants
BGAN terminals are allowed to be used on the open ocean on a moving vessel. But because the vessel will be moving there is great chances to lose the signal and then the connection. Inmarsat informed DPs that the Core network is not blocking these connections.
Inmarsat has created the FleetBroadband service that uses the I4 satellites for maritime communication.
Standard BGAN terminals cannot be used on moving aircraft due to doppler shift effects. An alternative service using more intelligent terminals to talk to the I4 satellites, named SwiftBroadband, has been developed for aircraft use.
[edit] News coverage
Sky News correspondent Alex Crawford used BGAN equipment to provide live coverage, from a moving truck, of the news network's coverage of the liberation of Tripoli, Libya, in August 2011. This was done by the producer continuously readjusting the BGAN terminal to track the bgan satellite. In-Motion BGAN satellite terminals are often used by media outlets for streaming video on the move. Another advantage to in-motion BGAN systems are for saving precious minutes when arriving at a live event. A media vehicle equipped with an in-motion system does not require pointing time since the in-motion BGAN terminal is already locked on satellite.
[edit] See also
[edit] References
- ^ "INMARSAT: Inmarsat Broadband Goes Global". http://www.tmcnet.com/usubmit/2009/02/26/4016324.htm.
- ^ "Inmarsat BGAN Terminals — Inmarsat". http://www.inmarsat.com/Services/Land/BGAN/Terminals/default.aspx?language=EN&textonly=False.
- ^ "BGAN Coverage — Inmarsat". http://www.inmarsat.com/Services/Land/BGAN/Coverage.aspx?language=EN&textonly=False.
