System and method for providing scheduled data communications in a communication system

A communication system comprising:

• a fixed network;
• a plurality of communication units synchronized in time with one another, each of the plurality of communication units being capable of communicating with the fixed network via a controlled access channel, the controlled access channel being delineated into a plurality of slots and a plurality of microslots;
• and
• a plurality of mobile devices, each of the plurality of mobile devices being coupled to one of the plurality of communication units;
• wherein each of the plurality of mobile devices comprises at least one application capable of generating a scheduled data message indicating when the data message is to be transmitted by a communication unit, the scheduled data message having a message payload, destination information, and a header having an hour field comprising information indicative of an hour during which the data message is to be transmitted by the communication unit, a minute field comprising information indicative of the minute during which the data message is to be transmitted by the communication unit, and a slot field comprising information indicative of a slot number during which the scheduled data message is to be transmitted by the communication unit;
• and
• wherein each of the plurality of communication units is configured to receive data messages from an associated device, determine that a received data message is a scheduled data message, and transmit the scheduled data message at a transmission time based on information in the hour field, the minute field, and the slot field of the header.