With the help of prioritised polling token and a local synchronisation scheme, this study proposes a quality of service (QoS)-guaranteed scheduling algorithm. It works based on distributed intelligence and schedules both intra-cluster and inter-cluster connections in a cluster-based multihop wireless ad hoc sensor network. Theoretical analyses are employed to derive the bounds for the jitter and delay of each intra-cluster and inter-cluster connection. Based on the obtained jitter bounds and delay bounds, a connection admission control scheme is proposed as the admission criterion for each newly requested connection. Both numerical and simulation results show that by taking the advantages of proposed polling-based QoS scheduling algorithm and the connection admission control jointly, the QoS requirements of all admitted intra-cluster and inter-cluster connections are guaranteed.