It has been well over 10 years since the MMR Network was first introduced to Victoria with the initial contracts signed between the Victorian Government and Motorola in 2004. The contract called for a fully operational date of 2006, just in time for the 2006 Commonwealth Games that Melbourne hosted. The MMR Network was to replace 3 analogue UHF systems then used by Victoria Police, Metropolitan Ambulance Service and the Metropolitan Fire Brigade.
The MMR Network has consistently achieved or exceeded its required levels of availability and has been a success, despite what you read on the internet by some chap that heard from his postman, who happened to talk to his wife’s friend who worked for Telstra and had daughter who dated a guy with a CB Radio. It’s done it, time and time again.
The original remote site equipment, consisting of P25 Phase I (FDMA) Motorola Quantar Intelligent Site Repeaters, each a 19″ rack unit weighing approximately 25kg, was upgraded during the 2013 – 2014 period to Motorola GTR8000’s.
With the upgrade to the GTR8000 came the ability of Phase II (TDMA) operation, software upgrade to core switching equipment, migration to a full IP architecture including all dispatch consoles, a new high-availability IP-based logging service to capture voice radio transmissions and the ability of inter-operating with all other Phase 2 enabled networks.
For those unfamiliar with how a trunking system works it is in short a computer controlled system that allows the sharing of radio frequency channels among a group of users.
Further information here: https://en.wikipedia.org/wiki/Trunked_radio_system
Now ever since the MMR Network was first designed the Victoria Police was very adamant that any voice frequency they used had to be partitioned from other users of the network. The main reason they did this was a measure towards ensuring that no radio of theirs was ever queued and left waiting for an available talk frequency. Queuing is obviously not what you want in event of a major incident with a multitude of talk-groups being used by resources combating said incident.
Subsequently other uses of the network did the same as Victoria Police. There have basically been three different pools of ‘talk frequencies’ sitting in the system, one for each entity using the MMR Network.
Whilst this might help to ensure a low ‘queued call rate’, it is not really making good use of the frequencies and could mean agencies possibly missing out on radio resources (talk frequencies / talk-groups) when needed and available as they may not be being used by the other agencies.
There are features built in to the system to minimise ‘queued calls’.
So now here we are in 2016 and over the last few years a much clearer path has been laid in regards to the direction that the State of Victoria’s existing and future radio systems are to take, some of it in part due to the disastrous events of 2007 during what has become known as ‘Black Saturday’.
Probably the most recent of those changes that many would be familiar with is in the new RMR Network currently in use by much of the Country Fire Authority. It is near identical to the MMR Network however based on VHF for rural operations.
Another change has been the inclusion of another frequency for use by the states paging network known as the Emergency Alerting System (EAS).
The main change for the MMR Network is the possibility of a new user migrating to it, that being the State Emergency Service metropolitan units, not to be confused with their country units who are apparently earmarked for migration to the RMR Network.
That brings me to the second possible change for the MMR Network and one I touched on earlier in this post, frequency partitions.
Recently I noted a few MMR Network sites running with un-partitioned frequencies, meaning VicPol, Ambulance Victoria and MFB are all sharing the sites allocated ‘talk frequencies’ for their talk-groups, just as Motorola originally designed the system for.
So far the un-partitioned frequency operations has been noted on the Chadstone and Surrey Hills (SiD 0164h-0109) simulcast sites with reports of this also possibly occurring on Keilor (SiD 0164h-0203) and the Epping and Greensborough (SiD 0164h-0113) simulcast sites. There has been talk of a further site which I’m yet to confirm (due to distance) such activity on and that this may have been ongoing since late 2015.
With the changing face of Victoria’s communication systems it would appear that the Emergency Services Telecommunications Authority (ESTA), who manage the MMR Network on behalf of the state and will also do the same eventually for the RMR Network, are looking to free up capacity.
If they wanted to increase capacity on the MMR Network by adding additional frequencies there would be hefty price to pay one would imagine, and at a guess I’m tipping that it is cheaper to remove partitions to free up the capacity already actually there, just not being used smartly, than add to it.
Knowing how adamant that the one particular user of the MMR were for the partitions to be in place originally I’m tipping it was no easy feat to convince them to do otherwise and would’ve even taken a detailed study and report to back those wanting to undertake such practises.
If you’re after a bit of light reading you can get an idea of some of what is planned for the State of Victoria’s communication networks here: