A communication device being a base station configured to communicate according to a protocol in which data is communicated via a series of frames, and every frame comprises: a downlink portion for transmissions by the communication device using a time division multiple access protocol, said downlink portion comprising a control portion; and an uplink portion for transmissions to the communication device using a time division multiple access protocol; and the duration of each frame is greater than one second, wherein the communication device is configured to communicate via a series of frames, each frame having the same duration, wherein the communication device is configured to communicate via a series of frames that each have a duration of 2 seconds, and wherein the communication device is configured to transmit the control portion using the lowest data rate supported by the communication device, and wherein the uplink portion has first channels for allocated uplink data transmissions in parallel with second channels allocated for uplink contended access; and wherein the control portion has an information field describing a channel structure and further has a downlink map portion that is disposed between the information field and a data portion following the control portion for sending data to terminals connected to the communication device, and that informs the terminals as to whether there is any information in the frame for each of the terminals and whether each of the terminals has an uplink slot reserved for a respective terminal to transmit information; wherein the information field includes a value indicating a length of the downlink map portion and a first spreading factor used to transmit the downlink map portion, wherein the first spreading factor corresponds to one of a lowest bit rate required by the terminals or that corresponding to the lowest bit rate supported by the communications device; wherein the downlink map portion has a table of terminal identities, a number of slots over which information for each of the terminals is spread over, information identifying a transmission mode, and information identifying second spreading factors used for transmitting the data for each of the terminals; and wherein the control portion of the downlink portion comprises an acknowledgement portion starting immediately after the downlink map portion is complete, wherein the acknowledgement portion includes data indicating acknowledgement of previous uplink transmissions, and wherein the data portion starts immediately after the acknowledgement portion is complete. a downlink portion for transmissions by the communication device using a time division multiple access protocol, said downlink portion comprising a control portion; and an uplink portion for transmissions to the communication device using a time division multiple access protocol; and the duration of each frame is greater than one second, wherein the communication device is configured to communicate via a series of frames, each frame having the same duration, wherein the communication device is configured to communicate via a series of frames that each have a duration of 2 seconds, and wherein the communication device is configured to transmit the control portion using the lowest data rate supported by the communication device, and wherein the uplink portion has first channels for allocated uplink data transmissions in parallel with second channels allocated for uplink contended access; and wherein the control portion has an information field describing a channel structure and further has a downlink map portion that is disposed between the information field and a data portion following the control portion for sending data to terminals connected to the communication device, and that informs the terminals as to whether there is any information in the frame for each of the terminals and whether each of the terminals has an uplink slot reserved for a respective terminal to transmit information; wherein the information field includes a value indicating a length of the downlink map portion and a first spreading factor used to transmit the downlink map portion, wherein the first spreading factor corresponds to one of a lowest bit rate required by the terminals or that corresponding to the lowest bit rate supported by the communications device; wherein the downlink map portion has a table of terminal identities, a number of slots over which information for each of the terminals is spread over, information identifying a transmission mode, and information identifying second spreading factors used for transmitting the data for each of the terminals; and wherein the control portion of the downlink portion comprises an acknowledgement portion starting immediately after the downlink map portion is complete, wherein the acknowledgement portion includes data indicating acknowledgement of previous uplink transmissions, and wherein the data portion starts immediately after the acknowledgement portion is complete.