A method and apparatus for admission control in a wireless train communication system with TDMA are disclosed. The method and apparatus according to one embodiment of the present invention identifies neighboring devices within neighborhood of a given device that use the time slot. The frequency and location information for the intended device and the unintended devices are used to determine whether to grant the time slot. In another embodiment according to the present invention, the receive signal strength information at the neighboring devices is used, instead of the distance information, for admission control.