Satellites and microwaves

We regularly cover live events on television, and while many countries have extensive networks capable of sending pictures back to broadcasters, that is often impractical and an alternative method is needed.

Microwaves

The easiest, quickest and cheapest method is to use a microwave link. This means the live camera or VT machine at the location is fed into a transmitter that is aimed towards a receiving dish. Microwave aerials are small, and are often mounted on the roofs of small vans.

Microwaves suffer from one major drawback – the receiving dish needs a direct view of the transmitting aerial. If there Is a hill in the way the signal will not get through. Given a clear ‘line of sight’ microwave signals can travel for as far as they can see.

However, it is possible have a series of links that ‘hop’ the signal to its final destination.

Satellites

Sometimes the outside broadcast wlil be at a place that would require a silly number of microwave links. At this point it becomes more economical to use a satellite. This involves sending the signal straight up towards a satellite in geo-stationary orbit, where it is picked up and sent back to a receiving station on the ground.

If you’ve ever tried to get a signal out from a city centre surrounded by skyscrapers you’ll know it is often easier to use satellites than microwaves.

Satellites are more expensive. Typically you hire them for a minimum 10 minutes, then by additional 5-minute time slots. It is difficult to give prices as so many variables come into the equation (bulk bookings, destinations, distances etc.), but as a guide you’ll pay around US$500 for the first 10 minutes, then $15 per minute after that. The point here is this stuff isn’t cheap, so be ready with your VTs/OBs when the lines come up (i.e. you are connected through the satellite). Don’t overrun.

Satellite up-iink dishes are much bigger than micro-wave dishes, and, while they can be mounted on trucks, they are not subtle.

Alternatives

If you don’t need to send pictures in real time (i.e. you are not doing a live link), then you can use a ‘store and forward’ device. This loads the pictures and sound into a computer memory, and uses much smaller satellites to send the pictures back to base. It takes a lot longer (typically 20 minutes to send a 2-minute piece) but it’s much cheaper to hire these data satellite links, and the original transmitting station uses a small satellite phone dish, which is more practical to carry around.

Courtesy Optex

Satellite uplink dishes are usually transported already assembled and are simply swung out of the truck and pointed (accurately) at the appropriate satellite. It is also possible to transport them in pieces, although this usually involves copious flight cases and a major excess luggage budget.

Courtesy Optex

Microwave links are much smaller and simpler, and can be mounted on basic tripods.

Apart from being much cheaper they can also, if necessary, be powered by a car battery.