There are currently products from multiple major and minor DMR equipment manufacturers to support single frequency repeater (SFR) function. They may have different names but essentially do the same thing: Repeater input on time slot 1 and output on time slot 2.
What is not certain is whether SFR is interoperable between different manufacturer equipment. From the description by each manufacturer it appears to be interoperable.
Extended Range Direct Mode enables repeater operation on a simplex radio channel. Radios on an ERDM channel transmit on one slot and receive on another slot - the frequency is the same.
With this you get:
- Repeater-like coverage
- No need for a 2nd frequency - your simplex channel can be reused.
In this configuration, dual slot operation is not possible and you need to be using a SLR series repeater. IP based dispatch solutions, like SmartPTT Plus and TRBONET Plus, are supported. It also only supports single site conventional operation so no trunking or IPSC.
This feature requires R2.7.0 firmware and is supported on all current generation MOTOTRBO radios. My understanding is that this feature will also work on other makes of DMR radios.
Full Duplex and Single Frequency Repeater
The UHF model variants of the MD785i are also available with Full-Duplex function and can thus also be used as Single Frequency Repeaters (SFR). In Repeater Mode the mobile radio boosts the range of a direct connection between conventional DMR devices without having to use a base station or repeater. In very concrete terms for users this means they now have more freedom of movement and considerably more flexibility.
Belfone: Repeater and Base Station
BF-SFR600 is our new single frequency repeater solution which is also able to function as a base station within a system. As a single frequency repeater, BF-SFR600 allocates one timeslot to receive a signal and the other to transmit it at the same frequency, using DMO mode to extend radio coverage.