Connecting radios all over the world

Mimer RadioServer

When you need to access your devices from several WAN or Internet based dispatchers.
The RadioServer will manage multiple TCP connections for you.

The RadioServer expands your system so that operators can be placed at different sites all around the world. The special satellite version also helps with the jitter that sat-links experience.

Mimer SoftRadio

Using the RadioServer

The Mimer RadioServer is needed in larger systems were TCP is used (usually when running over the Internet). A Mimer Network Interface can handle just one TCP-connected dispatcher PC at a time. (In local systems using UDP to connect, you can have many operators without a server)

The RadioServer solves this limitation. By installing a Mimer RadioServer at the base station site, multiple TCP-connected dispatchers can share each device.

The server can also be installed at a dispatcher central to distribute radio resources to other dispatchers over the Internet.

This is perfect when you have for example a taxi company with local dispatchers during the day and remote dispatchers at night. Or you have dispatchers that need to work from home.

Technical

The Mimer RadioServer Mk3 has a capacity of 256 connections each configurable for radio or dispatcher. Like this:

  • 2 radios x 128 operators
  • 4 radios x 64 operators
  • 8 radios x 32 operators
  • 16 radios x 16 operators
  • 32 radios x 8 operators
  • 64 radios x 4 operators
  • 128 radios x 2 operators

The Mimer RadioServer Mk3 is delivered as a self contained small Linux computer running on 12VDC. It will start by itself if there has been a power failure. It has low power consumption and is easy to install also with power back up.

Due to delivery shortage of PC components, the RadioServer might also be delivered in an alternative hardware. It meets all the same demands as the standard hardware.

Mimer RadioServer Mk3

Mimer RadioServer Mk3

Dimensions:
200x120x50mm, plus connectors
1050grams

Power:
Runs on 12VDC, 3,5A,  through
an adaptor that needs 100-240VAC

Alternative housing for the Mk3 RadioServer

Technical Issues

We gather technical questions and answers on this page!

Setup instructions can be downloaded from the technical download page.

Mimer RadioServer, front side

The old Mk2 version of the RadioServer

Virtual RadioServer

Mimer RadioServer is, as standard, delivered pre-installed on a SolidStateDisk mounted in a compact industrial x86 computer, as described above.

However some customers prefer to run the RadioServer on a hardware platform they are used to. The RadioServer can therefor also be delivered as an VDMK-file to be run on a virtual computer using Oracle Virtual Box or VMWARE. The Virtual machine will run a 32-bit Debian Linux machine. The virtual disk will be up to 4GB in size and requires at least 1GB of RAM (2GB recommended).

The current virtual machine file has been created and tested using Virtual Box version 6.1.

RadioServer Satellite Version

Takes care of high latency and high jitter.

Already in the standard version of the Mimer RadioServer, much higher levels of latency and jitter can be handled than in the standalone Network Interface.

For connections with extra demands there is also a special version of the RadioServer that improves this even more. Recommended for users with Satellite connections! If you are using an encrypted VPN tunnel over satellite, you must have the satellite version.

Windows has an “improvement” that causes problems for connections with a long delay, called “TCP Slowstart”. Sat providers usually can implement something called “TCP Spoofing” to counteract that, but if you have an encrypted VPN they cannot do that, and then you once again get broken audio. The solution is to use the Radio Server in Satellite mode together with the Network Repeater.

The satellite version of the RadioServer uses UDP Unicast for the communication, for this reason you always need a Mimer NetworkRepeater at the dispatch end. Please see drawings below.

RadioServer setup window

RadioServer – Web browser setup

Web browser setup menu

The Mimer RadioServer has a web browser based setup interface.

All settings of connected radios, IP addresses etc are easily done through a standard web browser. You can also change name, password etc.

There is also a list of previous settings so that it easy to revert to an earlier state.

RadioServer – Web browser status window

Web browser status window

The Mimer RadioServer has a web browser function were you can connect and see the status of the server.

You just need to browse the IP of the server and it will give you information on connected radios and connected operators.

It will also show what radios the operator is monitoring and if the operator is transmitting.

No changes can be made to the server from this interface, it is “look only”.

RadioServer / NetworkRepeater

In some cases a NetworkRepeater is the correct choice and not the RadioServer. In other cases you even need a combination of both. When using the satellite version, you always need a NetworkRepeater on the land side.

Read about the NetworkRepeater here.

Download a description off the differences between Mimer RadioServer and Mimer NetworkRepeater from the Technical Download Page.

System Examples

Showing some different examples where a RadioServer in needed.

System with operators at different sites

Connection with a Mimer RadioServer at the base station site.
The server can handle one or many radios at the same site and many dispatchers at different places.

System with operators at different sites, showing the TCP and UDP connections

Showing two of the radios connection through UDP to the RadioServer and two of the operators connection through TCP to the RadioServer.

Operator in City A talks to a car in City B over DMO

Example with several police stations with their own small systems. They are also connected together through their own WAN. With help of the RadioServers, operators at other police stations can remotely connect to each others radios.

In this case for operating a remote Tetra radio in DMO if the Tetra net does not function.

System Examples over satellite

Showing an example where a satellite version RadioServer is needed.

Mimer RadioServer in satellite mode

Connecting radios ofshore through a satellite link with the help of a Mimer RadioServer .

Mimer RadioServer in satellite mode, showing the IP connections

Showing how the ofshore equipment connect with UDP Unicast to the onshore equipment.

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