The performance of various channel access schemes in multihop packet radio networks with a regular structure is studied by means of simulation. The channel access schemes considered are: ALOHA (pure and slotted), Carrier Sense Multiple Access (CSMA), Busy Tone Multiple Access (BTMA), Code Division Multiple Access (CDMA), and a new hypothetical scheme introduced here for comparison purposes referred to as Coded Activity Signalling Multiple Access (CASMA). Network throughput and packet delay are evaluated, as well as the effects on performance of the nodal transmission scheduling rate, the propagation delay among nodes, and to some extent the input flow control. In this study, we consider networks in which both the topology and the traffic pattern are symmetric. This render all nodes in the network statistically identical, and thus helps reduce the complexity of the simulation task considerably without jeopardizing the objective. The performance of CSMA in such networks in shown to be rather poor as compared with its performance in fully connected networks, while relatively high performance is achieved by the CASMA scheme, the various BTMA protocols, as well as the CDMA scheme, as compared with CSMA and the ALOHA schemes.