In one novel aspect, a plurality of synchronization signal (SS) anchors within a block of a contiguous spectrum is configured in a wireless network. Each SS anchor is a primary SS anchor or a secondary SS anchor. The UE performs an initial access by detecting a first primary SS anchor and receives one or more virtual carrier configurations with corresponding SS anchors within the block of the contiguous spectrum. In another novel aspect, the UE performs an initial access through a first RF band with a first bandwidth and a first center frequency, receives a switching signal to switch from the first RF band to a second RF band with a second bandwidth and a second center frequency, the second bandwidth is different from the first bandwidth, and performs a RF bandwidth adaptation from the first RF band to the second RF band based on the adaptation signal.