This paper discusses a new approach to spectrum sharing being developed in Europe and the USA. To date sharing of bands has been undertaken on a hierarchical basis with the incumbent use having priority over new uses. This does not provide some potential new users, and in particular wireless broadband operators, with the quality of service and certainty of availability they require. A new approach is required to sharing that treats the incumbent and the newcomer in a symmetrical way – so they both have quality of service guarantee and legal certainty over access rights.