A network node in a communication system which transmits at least two reservation requests in order for the node to obtain radio resources for transmitting data. In the network, downstream signals are transmitted from the central control node to identify at least one upstream request opportunity in which nodes may transmit a request signal to the central control node. When a first individual node has data to transmit, the first individual node transmits a request signal to the central control node within the at least one upstream request opportunity. Subsequent to receiving the request signal, the central control node transmits a subsequent downstream signal specifying at least one subsequent request opportunity wherein the first individual node is assigned to subsequently transmit a subsequent request signal. In response to receiving the subsequent downstream signal, the node transmits a subsequent request signal in the subsequent request opportunity assigned to the node. Subsequent to receiving the subsequent request signal from the node, the communication controller transmits an additional subsequent downstream signal which allocates resources to the node to transmit data to the communication controller.