Techniques are described that provide for the collaborative co-existence of LTE-U base stations and access points associated with technologies, such as WiFi, that use unlicensed frequency spectrum. In one implementation, a LTE-U device may select a frequency block, in an unlicensed frequency spectrum, based on measured signal strengths and decoded Master Information Blocks (MIBs) that are broadcast in the unlicensed frequency spectrum. The LTE-U device may initiate communications via the selected frequency block by transmitting a MIB that includes a token identifier field that identifies the selected frequency block.