xMax uses one narrowband channel, but sends more data than could possibly be fitted into that channel - and yet it does not break the laws of physics, claims Bobier. The narrowband channel does not carry the payload, it is just used to co-ordinate and synchronise the sender and receiver. The information is then transmitted in a wideband signal (which xG calls a Flash Signal), at very low power.

"Our technology uses a narrowband channel, and places a carrier there for an extremely precise clock in the receiver," says Bobier. "The transmitter also transmits information in side bands, at levels lower than ultra-wideband. We are able to get performance comparable to a wideband licensed trasmission."

The data is sent out-of-band, but at power levels that are lower than those permitted for unintentional out-of-band signals by normal transmitters. "The levels of out-of-band emissions are highly regulated," says Bobier. "Ours are even lower."

The synchronisation allows the receiver to pick out signals below the noise floor, claims Bobier, so a signal that is not registered by other spectrum users, can be picked up by the intended recipient. There is some explanation in a FAQ at xG, and an article in Microwave Engineering.

...less than one Watt, using the unlicensed 900MHz ISM band..