Motorola MTS 2000 LMR connecting to e&m

[Patrick Laidlaw]

I'm working with connecting Land Mobile Radios to voice enabled networks. I've been tasked with trying to get a Motorola MTS 2000 handheld connected to it via an e&m port.

I've connected the radio to an E&M port via a modified cable which normally would connect to a handset/earbud. The e&m port is able to get the radios attention and transmit just fine but not the other way around.

The issue I'm hitting is getting the radio to get the attention of the E&M port to listen to the conversation going on. From my understanding the MTS cable we have is not capable of appliying voltage so that the E&M ports attention is gotten.

After talking to a radio tech he said I would have to use some sort of vad on the e&m port. I didn't really see any way to do this and was hopeing someone might know more.

Here is the config I have on the voice-port

voice-port 1/0/0

voice-class permanent 1

lmr e-lead voice

lmr duplex half

auto-cut-through

operation 4-wire

type 3

signal lmr

timeouts call-disconnect 3

timing hookflash-in 30

connection trunk 1100

description MTS2000 Flashport

music-threshold -10

threshold noise -90

dial-peer voice 100 voip

description MTS2000 Flashport

destination-pattern 1100

session protocol multicast

session target ipv4:234.1.100.1:30090

codec g711ulaw

vad aggressive

[shoresw]

It almost sounds as if you're trying to provide a potential client an interoperability solution (such as Twisted Pair Solutions WAVE technology) to bridge the gap between LMR, IP/Analog phones, and PC clients.

You may want to try the TCB-1. It will allow you to use a handheld radio system including the Motorola MTS 2000 Flash Port. The URL is:

http://www.link-comm.com/ftp/tcb1/TCB-1_Brochure.pdf

The reason you need this is because very few radio systems, if any, provide COR (m-lead) on recieve activity. That is why the radio guy you talked to explained that you must rely on VOX/VAD. However, VAD is bad because you will be getting the "shoot" "don't shoot" effect. The TCB-1 provides a small delay that will reduce this, if not alleviate it.

I hope this helps.

Billy