Communication

 

The soccer server provides a challenging communication environment for teams of agents. With a single, low-bandwidth, unreliable communication channel for all 22 agents and limited communication range and capacity, agents must not rely on any particular message reaching any particular teammate. Nonetheless, when a message does get through, it can help distribute information about the state of the world as well as helping to facilitate team coordination.

All CMUnited-98 messages include a certain amount of state information from the speaker's perspective. Information regarding object position and teammate roles are all given along with the confidence values associated with this data. All teammates hearing the message can then use the information to augment their visual state information.

The principle functional uses of communication in CMUnited-98 are

• To ensure that all participants in a set play are ready to execute the multi-step plan. In this case, since the ball is out of play, time is not a critical issue.
• To assign defensive marks. The captain of the defensive unit (the goaltender in most formations) determines which defenders should mark or track which opponent forwards. The captain then communicates this information periodically until receiving a confirmation message.

For a detailed specification of the communication paradigm as it was first developed for CMUnited-97, see [10].