Interest on using mobile autonomous agents has been growing, recently, due to their capacity to cooperate for diverse purposes, from rescue to demining and security. However, such cooperation requires the exchange of state data that is time sensitive while achieving timeliness with RF communication is intrinsically difficult due to the openess of the medium. This paper describes a communication layer that improves the timeliness of periodic data exchanges among the team reducing the chances of lost packets caused by collisions between team members. In particular, the paper extends a previous proposal for an adaptive TDMA protocol with new self-configuration capabilities according to the current number of active team members. This feature further reduces the likelyhood of collisions within the team. Several experimental results with an actual system implementation show the effectiveness of the proposed solution.