A media access protocol, CSMA/CD-W (Carrier Sense Multiple Access with Collision Detection for Wireless) is proposed to support broadcasting and point-to-point communication in mobile robot based distributed robotic systems (DRS). Distinct from many existing experimental systems built with off-the-shelf wireless communication products for computers, no centralized mechanism such as a communication server, or "ground support" is used, which is consistent with basic principles of DRS. The proposed protocol supports wireless data communication among mobile robots on a shared radio communication channel. It differs from CSMA and its variations with the capability of detecting, in a wireless network, collisions of broadcast (undesignated) messages without using any centralized devices. Satisfactory performance of the protocol is demonstrated with a rigorously designed discrete event simulation.