LIPD's, eh? What could possibly go wrong?

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https://www.smh.com.au/national/western-...51305.html

Perth's Lakeside Joondalup shopping centre management believe they have partly solved the mystery of what was preventing people in their car park from being able to lock and unlock their keyless entry cars.

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Local pdf of SMH page in case it disappears:


  Authorities locate device jamming keyless entry signals at Lakelands Joondalup.pdf (Size: 179.32 KB / Downloads: 468)

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Mmm

Radiocommunications (Low Interference Potential Devices) Class Licence 2015

https://www.legislation.gov.au/Details/F2015L01438

A plan that maybe does not work out as it is supposed to.

70cm repeaters of course never suffer from interference from LIPDs on their input frequencies.

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From the linked legislation:-

Note 1       A transmitter operated under this Class Licence can be expected to be operating in parts of the radiofrequency spectrum used by other radiocommunications devices.  A receiver tuned to the transmitter will not be afforded protection from interference caused by other radiocommunications devices.  A low interference potential device operated under this Class Licence is generally not expected to suffer interference, however an individual low interference potential device may experience interference arising from the particular circumstances of the device’s operation.

And yet the ACMA and who knows who else are out in force working on the problem while ham's get stuck with the suck it up approach.

Usual story - money talks and b******t walks.

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Perth sunday times said it was a pager thing that tells people when their script is ready

They give you a dongle? thing? and you walk around shop and it lights up when script is ready?

so you walk around with a lipd receiver in your hand

lots of fun

vk6ro

e&oe

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If that's the case it is no doubt similar to the systems used in bistro's and clubs.

Only they may have 'upped' the output so it works in other shops in the shopping centre.

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The thing about this story is that we don't actually know which LIPD allocation is being used by the keyless access devices in these modern vehicles..

An extract from https://www.acma.gov.au/-/media/Spectrum....pdf?la=en , titled Radiocommunications (Low Interference Potential Devices) Class Licence 2000 

....
15 All transmitters 1. 70–70.24375 2. 77.29375– 77.49375 3. 150.7875– 152.49375 4. 173.29375–174 100 mW 
16 All transmitters 1. 225–242 2. 244–267 3. 273–303.95 4. 304.05–328.6 5. 335.4–399.9 10 µW 
17 All transmitters 433.05–434.79 25 mW 
18 All transmitters 915–928 3 mW 
19 All transmitters 2400–2483.5 10 mW 19A All transmitters 5725–5875 25 mW 
20 All transmitters 1. 10500–10550 2. 24000–24250 100 mW 
.....

The local assumption is that it is the section 17 values of 433.05 to 434.79 but who really knows ?
The 25mW limit might have been the issue .. and was replaced by a significantly higher power level in practice.

Also 
"4 Class Licence (1) This Class Licence authorises a person to operate a transmitter included in a class of transmitters mentioned in an item in Schedule 1, subject to the following conditions: (a) the transmitter must be operated: (i) on a frequency, or within a range of frequencies, mentioned in the item; and (ii) at a radiated power that does not exceed the maximum EIRP mentioned in the item; and (iii) within the limitations (if any) mentioned in the item; "

So that becomes 25mW EIRP.................

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Car access systems are 433.92 MHz, although in Europe, they are opening up 868MHz for use as well.