i'm doing a project on nurse call device.. consist of transmitter and receivers. each patient will have their own transmitter but at the nurse call station there's only 1 receiver getting the signal.. however we encounter problem when two transmitter send signal at the same time.. both of the signal will be rejected.. i need to know if anyone out here know any multi-channel RF receiver. and also i might need help with interfacing the 8051 with the receiver.