I received the following item on 31 January 2000 from the folks who are building the new 800T statewide system for Pennsylvania. Seems like cutting edge stuff. ========================= Peter, Thanks for your interest; sorry for my delay in replying. Responses by number to your questions:

1. The system is capable of full-duplex operation, but most agencies will not use full-duplex. Consoles have priority for voice access over field units. Consoles can monitor any number of desired talk groups simultaneously, depending on the hardware and software configuration selected by the using agency.

2. The trunked system automatically prevents "doubles" from occurring; only one user is granted "talking rights" to a given talk group at any time. No special provisions are necessary.

3. Any mobile unit may have its configuration modified remotely by a "dispatcher" with appropriate permission and access to the appropriate computer hardware. As you can imagine, this will most likely not be done by all dispatchers, nor will it be done often.

4. Your information regarding the vehicular repeater is correct. Actually, the portable radio detects loss of signal, switches to the v.r., and activates it. The v.r. makes use of the TDMA protocol's ability to talk during some time slots, and listen during others, to accomplish this feat. The v.r. is actually two mobile radios, back-to-back, with additional controlling software. The use of different time slots greatly reduces the receiver desense problem that limited most legacy v.r. equipment.

Hope this helps, and thanks again for your interest.