The next generation GPS (generically part of GNSS or Global Navigation Satellite Systems) by international agreement will broadcast a whole new range of signals – particularly if the new European system Galileo takes off. These new signals will adopt a different type of modulation called Binary Offset Carrier (or BOC). Although it is an ingenious concept, there has been a well-known difficulty in the receiver implementation. In his talk Stephen Hodgart will describe the new signals, and this problem of implementation (without heavy theory). He will also explain how the concept of a dual estimating receiver, invented here in Surrey, overcomes it. The way now seems clear for future technical development of BOC-GNSS without problems.