PMR
Mixing Tetra with cordless phones W
ith an upgrade to the alarm loca- tion server from Funkwerk Security
Communications, DECT cordless phones and Tetra radios can be combined on the same server, with cross-messaging. Dietmar Schöps explains that the combination can suit work- places such as pharmaceutical plants where Tetra radios are used out on the plant but pocket-sized DECT devices may be more con- venient for workers in laboratories or offi ces. “On the DECT phone you usually have
messaging to alarm people, but if you need a verbal group communication, then you move to Tetra”, he says. “And as both technologies are using the same indoor localization beacon
Connecting DECT and Tetra: Dietmar Schöps, of Funkwerk Security Communications
and the same type of messaging and the same application server, those two technolo- gies can be combined. So if you move into a building with your Tetra terminal, you are located with the beacons which are usually used for the DECT phones which are inside the building. “In an alarm scenario, you send mes-
sages to both, and for the alarm server and the person who is dealing with the alarm it appears as one system. Even if you have a certain group in mind, which is gathered from Tetra terminals as well as DECT, you get the responses back from both. “You can create a message on the DECT
DECT cordless handsets for professional communications, by Funkwerk
phone and send it to a Tetra terminal and both technologies provide a connection to the PABX so you can talk between the systems. You can have a group conversation between the systems, so it’s seamless – both technolo-
gies integrate seamlessly. Including, as I said, messaging means you can use the DECT system also for telemetry applications. It need not necessarily be a Tetra radio.” The alarm server also handles responses to
emergency calls. “What we have here is the so-called warning alarm, which is very much used in hospitals or elderly homes to ask for help”, Mr Schöps continues. “If you are in a situation which you cannot do alone, you simply press that button. The alarm server will inform other nurses and the one who takes it retrieves the alarm from the others. So you know that this one has been taken and you don’t have to care for it any more. That can be done with DECT and Tetra in parallel. If somebody on a DECT phone takes the call, it disappears from the Tetra terminal as well.”
• Information:
www.funkwerk-sc.com
tenna specialist RFI Industries. “It measures the output power of individual transmitters after the transmit combiner”, explained Kevin Book- er. “We put a decoupler in the coaxial cable line going from the combiner to the antenna and we sample off that. “We program this with each of the frequen-
Assuring a quality PMR service for all A
unique maintenance aid for radio site op- erators was shown by the Australian an-
the values that are preset, it simply allows it to go through. “If it’s outside of those parameters, it gives you
cies, we program an upper and lower power limit, and upper and lower VSWR limits, and also an insertion loss limit. So as the transmitter transmits, part of that signal is passed through the monitor. T e monitor goes to its look-up ta- ble, has a look at the frequency, has a look at the parameters – and if the parameters are within
LAND mobile January 2013
an alarm condition. And then you can go into it and you can remotely access it by TCP/IP or the Net, and then you can have a look at what the alarm condition is. Is it a high volts alarm? A low volts alarm? T en you can make a decision about what action you need to take. “It’s unique in the fact that we are doing it
per-channel after the transmit combiner. T at takes the whole RF path into account. So you are looking at the power that is actually going to the antenna.”
• Information: www.rfi
.com.au
Kevin Booker, from RFI Industries in Australia, with a novel antenna systems monitor
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