Because of the short-range characteristics of UWB or 802.15.3 networks (around 10 m), it is highly desirable to have a range extension technology for future wireless personal area networks (WPANs). In the 802.15.3 standard, coverage extension is achieved by creating child or neighbor piconets from a parent piconet. One of the main disadvantages of this approach is that it does not make use of the multi-channel capability provided by the underlying physical layer (e.g. multi-band OFDM) as both the dependent and parent piconets operate on the same channel. As a result the capacity of the wireless medium is not fully utilized and the service quality of high rate A/V applications will suffer. This paper first describes a device association scheme to avoid unreachable communication pairs in network initialization. It then proposes a mesh network architecture and a simple, low-cost method for establishing communications across multiple piconets via multi-hop connections. It can be used to extend network coverage through connecting piconets on multiple channels.