In this paper, we propose a bandwidth routing algorithm in a multi-hop packet radio environment, which is not necessarily a cellular structure network and could have no fixed base stations. Each mobile station has the responsibility to transfer packets for others. The wireless network can be either stand-alone, or connected to the wired network such as ATM. To emulate cellular structure, we divide all the mobile stations into clusters. Bandwidth calculation is based on a reservation-TDMA scheme and the clustering structure. In this algorithm, every mobile station builds a routing table for every possible destined station, with knowledge of bandwidth information for each recorded path. The key issue in path bandwidth calculation in this multihop wireless environment is that the bandwidth of a path consisting of several links, is not simply the minimum bandwidth of these links. Additional consideration on the common free slots of these links may decrease the path bandwidth. By this more precise calculation, the packet loss rate can be very low and the call dropping rate is controlled. This is very important for the connection quality to be guaranteed and thus makes the QoS routing possible for real time traffic in local multi-hop packet radio environment. It also makes this environment compatible with the wired network, such as ATM.