Following a 2.5-year conversion of their conventional UHF radio system to a trunked DMR network from Tait, LG&E and KU chose Mimomax 900 MHz Tornado radios for their voice backhaul for a selection of sites in remote mountainous areas of Kentucky and Virginia.


The Challenge

With a team of line technicians requiring stable communications links to dispatch during service restoration or line work, it was imperative a solution be found for sites where there was no ability to connect to the utility’s existing microwave or fiber networks.

“The terrain in some of these areas is difficult. Two of the sites were co-located with water tank facilities, out in the mountains and miles off the road up with no cabling available at all,” said LG&E and KU Telecom Engineer John Pulliam.


The Solution

The Mimomax radios were selected for the voice backhaul due to their performance at sites with terrain challenges, plus the high capacity offered by the MIMO and full duplex operation. Modelling showed that the paths could comfortably carry a DMR Control Slot plus three DMR Voice Slots and could utilize 64QAM in a 12.5 kHz channel as a minimum, while offering higher than Five Nine’s (99.999%) two-way time availability.


“The team at Mimomax had demonstrated that with the data capacity of their radios, we could support far more voice channels than previously and with Five Nines availability. We went from a single channel that everyone had to share to now supporting three simultaneous conversations, with the ability to expand to more channels in future if we required,” added Pulliam.


Upon completion of two days of training, the LG&E and KU team were ready to deploy the backhaul radios which had arrived pre-configured for quick deployment. “We’re now working to identify coverage gaps in our DMR network where we might want to add new sites. When it comes to areas that are difficult to connect, the Mimomax radios are an ideal fit,” Pulliam said.

Pulliam noted that the LG&E and KU team are currently working with Mimomax to replace communications at another site where their carrier is no longer offering support for the T1 that had been used for voice backhaul. “Given this site is our furthest site in Virginia and therefore the one with the greatest distance to get a team out to if the site goes down, we’re keen to swap the T1 for the stability of a Tornado radio.”

Find out more: download the LMR Backhaul Linking brochure.