Satellite Internet Forum

[Robert_Brown]

Do you guys know about RaySat StealthRay Ku band outdoor receiver unit?  This is a two-way antenna which can be installed on car or train in order to provide passengers Internet access when the vehicle is mobile.

Could you please provide any other information about the products/ price/ supplier contact? I heard that its price could reach $40,000!

[mobileJohn]

It is a low gain tracking antenna which means a broad beam-width and problems with interference from adjacent satellites. You might get round this using an extra high power downlink carrier from the satellite and spread spectrum modulation. Both will greatly increase your space segment costs, possibly by as many as 8, 16 or 32 times!

Regarding uplink transmission, the are similar problems with a broad beam and spurious sidelobe radiation interference into the adjacent satellites. Before even considering transmission talk to the proposed satellite operator regarding permission to operate this specific device. Every satellite is intersystem co-ordinated with the adjacent ones so that all transmit earth stations dishes operate to the wanted satellite only. Sidelobe interference into adjacent satellites must be kept below acceptable limits. This means transmit dishes must have good off-axis discrimination: this high main beam gain versus low sidelobe pattern gain. Good x-pol isolation is also needed to avoid x-pol interference on the wanted satellite.

If you want mobile communications I recommend INMARSAT satellites and BGAN type terminals. INMARSAT satellites are spaced widely across the sky and operate in an exclusive satellite mobile frequency range so as to allow small, even hand held, antennas to operate without jamming the adjacent satellite. The latest INMARSAT network comprises three I-4 satellite, I-4 Americas at 98West, I-4 EMEA at 25East and I-4 Asia-Pacific at 143.5 Eat. Most of the time the 'adjacent satellite' will be below the horizon and your hand held antenna does not receive or cause interference to the adjacent satellite.

Ku band mobile VSAT is possible with moderately large 0.6m, 1.2m or 1.8m tracking antennas, in radomes like this:

Sea Tel - SeaTel Maritime mobile antenna

seatel-boat.png (245.12 KiB) Viewed 462 times

Smaller radomes for yachts and vehicles are possible, particularly for receive only satellite TV applications, see SeaTel antennas.

[Robert_Brown]

But the one you recommend is a very big boob

I wonder if there is a flat-plate dish installed on the top of my car so that I could have Internet access and my car looks smart!

Do you guys know about the price level?  This is my major concern. Thank you!

[acomdata]

There are flat plate type Antennas basically phased array technology BUT the development is still in my view early days and the TX part normally at best is around a 75cms efficiency , you will need either a very high power satellite or small carrier for it to work well.

[Robert_Brown]

I found from this link - SATELLITE TV BLOG ~ SPEEDRAY 3000 - that SpeedRay 3000 from RaySat just costs around $3,500!  And it seems to be under mass production. Nowadays such technology seems to be quite common. It looks smart and great!

Is what the link quotes possible?  Anybody knows about the price? Thank you!