AbstractThis paper proposes a new spreading code protocol (GBCR protocol) suitable for ad hoc DS/CDMA wireless data networks, which is co‐ordinated by a central station (CS) that tracks user's status. Users are divided into groups, each of which is assigned a ‘group‐based common’ (GBC) code used by transmitters in the group to acquire the current state of their targets from the CS. Data communication is allowed only after a positive ACK packet from the CS is received, so that all successful terminals are effectively sheltered by the CS from third‐party colliding packets, which are encoded by the same receiver‐based code. Analytical results reveal that the GBCR protocol can improve network stability and throughput‐delay performance, while still keeping the hardware as simple as possible. Copyright © 2001 John Wiley & Sons, Ltd.