Eating my words - cellular based radio

[cedd]

We've got a new radio system at work. I was a pretty vocal opponent to it, as it's cellular based, using 4g connected android devices (specifically designed for push to talk applications). I was all for a digital trunked system to replace our analogue duplex channels, but this felt like a step too far in to the unknown. 

It's brilliant! 

We've got 80 odd handsets on site. All dual sim, and wifi as well, so multiple routes to the server. Pretty much unlimited numbers of groups, direct calls between handsets, monitoring of multiple groups etc. All handsets can be geofenced to kill them if they leave site. Equally if you wanted you could use them anywhere in the world and it'd be as if they were on site. Dispatcher software on a laptop can see the location of all handhelds on a map. Options for things like emergency buttons, fall detection etc. (that sends a google map link to where you are to other users on the channel). The dispatcher can have a mic connected and talk to multiple channels at once. Text messaging features. Options to be able to send photos etc. 
The audio quality is excellent. Noticeably better. There's a touch of latency - maybe half a second. When you PTT you've got to wait maybe a second for it to establish connection to the server and then beep to say you can talk, but if anything that has actually improved our radio traffic, as everybody now waits for the beep and there are no clipped transmissions. You can do over the air updates to all of the handsets to change functionality, permissions, groups etc. so no more having to gather up all the radios to reprogram. 

The handsets are more expensive than a UHF radio, but not ridiculously so. The main expense then is software licensing. Maybe not a viable alternative for an independent theatre with a dozen radios, but a larger event centre, group of theatres buying one license, or something else along those lines would definitely benefit. 

Our users seem to love it, and the site coverage is perfect.
Not going to share details of the system we've bought publicly on here, but if anyone wants to know more they can DM me. Sharing as an engineer who's spent his career maintaining analogue and digital radio systems and has seen the future! 

[paulears]

With the slight delay, does this wipe out vox operation? I’ve got a little job coming up where I need a radio to transmit where the user will not have a free hand. It’s a drone pilot who needs to give a cue to a distant camera, and the path is marginal. With the need to listen for the system open beep, is vox even possible?

[cedd]

8 hours ago, paulears said:

With the slight delay, does this wipe out vox operation? I’ve got a little job coming up where I need a radio to transmit where the user will not have a free hand. It’s a drone pilot who needs to give a cue to a distant camera, and the path is marginal. With the need to listen for the system open beep, is vox even possible?

That's a good question that I don't know the answer to! We don't have headsets on ours, although I know they can connect to them. 

Fir your use case I think this one might not be the best solution - with software license costs etc. it leads itself to a larger system where the cost is shared out a little more. 

Can give you their details though if you'd like to have a talk? 

[sunray]

I'm a member of Raynet, an Amateur radio emergency service, and as training facilities we cover events with comms.

One such event is a right royal PITA due to the deep valleys and to cover an area less than 10 miles in diameter we use 3 linked repeaters. For the service we expect a 'donation'. Having covered this event for about 10 years the organisers were approached by Icom and lent enough handsets for each marshal point, back up vehicle, official, controls staff etc. I guess about 30-40 sets.

The write up in several trade magazines by an 'independent provider' were a glowing testimony to the amazing system... except we knew from experience the cellular coverage in the area was appalling (I think it's better now) however the organisers asked us to be in attendance the following year and ever since as they had very poor coverage.

I have very successfully used such sets/systems and agree they can be amazing, and as mentioned, over considerable distances. Furthest being Alton Towers/Longleat/home as the family had gone off in different directions for a weekend. Of course there is only one limitation and that is having a good internet connexion and as already mentioned that can be via pretty much any route.

Basically they are only a form of VOIP, just like internet based telephone systems and some of the handsets are able to interconnect with phones.

Some systems are much slower than others to connect, one of the ambulance services (similar to St John etc) ditched (actually decommissioned and disposed of) their FM radios in favour of the donated facility and very quickly found it wasn't as promised with anything up to around 15 seconds to connect. They very quickly moved back.

[sunray]

33 minutes ago, cedd said:

That's a good question that I don't know the answer to! We don't have headsets on ours, although I know they can connect to them. 

Fir your use case I think this one might not be the best solution - with software license costs etc. it leads itself to a larger system where the cost is shared out a little more. 

Can give you their details though if you'd like to have a talk? 

I've seen VOX attempted but sadly in a control room situation where there was too much noise. So yes at least some sets have the facility and all that's required is to make enough 'rhubarb' for long enough to make the connexion.

[paulears]

The drone operator will be on one side of a hill, and a cameraman on the other needs to know when it will pop up. Radio should be easy, but the camera position is next to a rather nasty pager site and it wipes out VHF, and the third harmonic also spaces around on UHF - UHF works but is a bit unpredictable. Network radio, with a Vox could be a solution.

[TomHoward]

I've seen similar handset setups used by our local volunteer Search & Rescue guys, where they've moved from UHF to 4G. I had a look at one of their handsets and also with them, the handsets were not a major cost factor but the server / central cloud service they all connected to was.

I didn't have a close look at them, but I did wonder whether it'd be viable to host your own server for these? I assume the working is somewhat like streaming, is there a standard protocol they work on that maybe one day the software licensing won't be needed as an ongoing cost or you could self host?
 

Obviously a feature set in a pro environment with all the permissions etc you're still going to need a more complete package, but for less professional / more back-to-back UHF replacement without all the trunking is it viable to program/host your own?

[Paul TC]

One comment if using in a small number of rural areas, that the LTE radio site may be using satellite back haul which will add delays to the voice transmission in addition to any other latency in the solution.

[Jivemaster]

Let's just hope that your mobile (sim) has a high enough priority indicator. During the London tube bombings the mobile phones went off including the bomb disposal teams phones.