Photos: Crave pays the BBC's R&D department a visit

While this may look like something that was knocked up with a bit of coat hanger and a piece of spare wood it's actually a working transmitter.

In this photo you can see the two sets of elements, set 90 degrees apart from each other. The polarisation of these elements is part of the reason why two sets of data can be sent over the space normally used for one, effectively doubling the capacity of a single channel. While this MIMO stuff isn't especially new, this is an incredibly simple way to get something for nothing, and it really does work.

Used for very low power tests and demonstrations, it shows how the whole system works and how easy it would be to roll the system out across the country.