Yes. TETRA System Releases 6 and above from Airbus DS include ISI functionality.
Yes. Multivendor implementations are possible.
Yes. In addition to group calls and one-to-one calls, the ISI standard includes covers status and text messages.
The physical connection is via fractional E1. A call occupies a 64 kbit/s E1 slot.
As long as the two networks support ISI functionality that adheres to the current ETSI standard, communication across network borders is possible even when the two networks have a different vendor.
Smooth communication across network borders is possible when the vendors providing TETRA interconnectivity have similar commitment to ISI.
Critical communications / 31 January 2023
Critical communications / 15 December 2022
Critical communications / 29 November 2022