Uncapped VSAT launched by MWEB Business

[Fulcrum29]

Speed increase also increases to massive costs whereby it simply isn't feasible for regular but becomes extremely remote business case use only.

Also I believe services pushing those higher speeds aren't VSAT in the traditional sense.

I don't know how they class these services, only know about certain local developments and plans, the max they have on VSAT is 16 Mbit/s and above this is regarded as experimental.

Yep, then there are these recent developments, herewith a Wiki link:

http://en.wikipedia.org/wiki/Satell...encies.2C_but_lower_speeds.2C_of_lower_orbits

Acceptable latencies, but lower speeds, of lower orbits

Medium Earth orbit (MEO) and low Earth orbit (LEO) satellites do not have such great delays. For example:

• The current LEO constellations of Globalstar and Iridium satellites have delays of less than 40 ms round trip, but their throughput is less than broadband at 64 kbit/s per channel. The Globalstar constellation orbits 1,420 km above the earth and Iridium orbits at 670 km altitude.
• The proposed O3b Networks MEO constellation scheduled for deployment in 2013 would orbit at 8,062 km, with RTT latency of approximately 125 ms. The proposed new network is also designed for much higher throughput with links well in excess of 1 Gbit/s (Gigabits per second).
• The planned COMMStellation, scheduled for launch in 2015, will orbit the earth at 1,000 km with a latency of approximately 7 ms. This polar orbiting constellation of 78 microsatellites will provide global backhaul with throughput in excess of 1.2 Gbit/s.

Unlike geostationary satellites, low and medium Earth orbit satellites do not stay in a fixed position in the sky. Consequently, ground based antennas cannot be easily locked into communication with any one specific satellite. As with GPS, the small orbits may cause a low Earth orbit satellite to only be in the sky for an hour or less before it goes over the horizon and out of range, so a complex relaying and passing-off needs to be done to hand over the fixed-position terrestrial signal to other satellites passing overhead.

Communications with MEO or LEO satellites that are moving in the sky can be done in two ways:

• More diffuse or completely omnidirectional ground antennas capable of communicating with one or more satellites visible in the sky at the same time, but at significantly higher transmit power than fixed geostationary dish antennas (due to the lower gain), and with much poorer signal to noise ratios for receiving the signal.
• Tracking, high-gain, narrow beam antennas, but the tracking requires more expensive solutions like a motorized antenna mount or a dynamic phased array antenna that can steer the beam electronically, and complex software that can predict the path of each satellite in the constellation.

Google also invested into O3b Networks.

In relation with traditional satellite services:

The average latency is estimated as 638 ms,

Max upload is 10 Mbit/s, (average - 256 Kbit/s)
Max download is 1 Gbit/s (average - 1 Mbit/s)

My brother in Canada have their internet powered by Xplornet (Telesat Canada) which utilised the KA band system:

The KA band system uses 'Spot Beams' to manage bandwidth concerns, linking to multiple satellite ground stations connected to the Internet.

The idea behind these Spot Beams are round trip latencies lower than 500 – 600 msec and high-speed. Here is a nice resource on O3B Networks, http://www.o3bnetworks.com/media/21...satellitecommunicationssystemfinalversion.pdf (PDF).

Note that they are trialling something (satellite service) in SA that is more than 30 Mbps.

 

[SauRoNZA]

Yeah but those fall very much in the "laboratory conditions" version of reality.

Like I said though the moment cost comes into play nobody but the military cares to afford those speeds and even they kick back.

As the wiki says with 60 satellites spinning around the earth the handover and interconnect between them is very complex and we have people complaining about dropped calls all the time. Data is less noticeable but still it's problematic.

Also V-Sat is heavily affected by weather unlike L-band and Ka-band. V-Sat is Ku-band as I recall but I might have mixed them up a bit now.

Geostationary is the most solid and stable and I know Inmarsat are also launching new satellites for a high speed (mobile) service at the moment that promises speeds up to 60mbit with a smallish dish system.

Hardware will come at astronomical cost though, unlike the relatively cheap V-Sat. But then again mobile is always more expensive.

Stationary mounted system do pose a massive increase in bandwidth but I'm yet to see real work latency that is consistently below 750-800ms.

Average of 638ms seems a bit optimistic, but I would be very happy if that is the case.