Through the terrestrial network, the fixed station connects to a LES. The LES sends a signaling message to the NCS, which in turn pages the MES via the NCSC. The MES receives the session oriented signaling message with its Forward MESID, and sends a response back to the NCS with its Return MESID. The NCS in turn sends a channel assignment signaling message to both the MES and LES, and both stations will tune to the assigned traffic channel, where the session will take place. The traffic channel carries all user data (voice, fax, data) plus signaling messages as required. At the end of the session, the traffic channel is released and the LES informs the NCS, that the channel is free again. The NCS returns the assigned channel and channel equipment to its pool of available resources.