Karizma + Fault

[Roger99]

It seems to me that they are more worried about 862 not 868. However it was an intresting read.

For some info certain makes run with agility hopping.

If you look at the frequency spectrum in the various links you will find that the 868 MHz band is also affected by radiation from 4g transmissions, but to a slightly lesser extent.

If by agility hopping you mean frequency hopping, this will not help at all because the 4g out-of-band radiation is inherently broadband and will cover the entire available 868 MHz band. Frequency hopping is only effective against similar narrow-band transmissions.

This is an issue that primarily affects equipment manufactures as they look to find alternatives.

As an installer, all you will be able to do is ensure that any radio-based accessories are kept close to the main panel so that high signal levels are maintained. If the sensor is far from the panel its relatively weak signal may be blocked by the 4g transmissions. Although this won't cause an immediate false alarm if the signalling protocol has been correctly designed, the blocking will produce a similar situation to a deliberate jamming attack. My understanding is that radio-based systems are designed to alarm under such conditions.

Anyway this is getting away from my OP. I was just explaining why I wouldn't personally install a radio-based alarm system.

[Oxo]

Some hate RF some love it.

I like it, it has its place when fitted correctly.

Texecom do what is called Ricochet, and uses each item as a extension so would avoid most of what you mention.

Although you can cause a "blockage" if there is a limited amount of items near the panel and one has to "work harder". But it does seem the way forward.

( Adrian cash is preferred and in used notes).

But as you say too many are crowding the limited bands available and the internet revolution and now 4G is not going to help for sure.

[Roger99]

I've had a quick look at that Texecom.

It's probably the best way to go because mesh systems are inherently resistant to interference. However as a radio engineer I know when it's best to stick to copper wires and I'm going to do so in this case!

[Oxo]

Not dissagreeing, but have had cases where WF was the only option. G1 listed building for example.

Also fire oficer demanded door closers, but the doors were 300 yrs old. So had to fit Perko`s. Was a bad day when some of the plaster arichtrave fell out. But we restored it.

As I say, it has its place. Where you can of course hard wire.

And you of all people know a bit of copper is a good antenna.

[AdrianMealing]

Latecomer to this thread, but we have tested our Ricochet equipment at BT's Baldock facility in preparation for the 4G roll-out, i am happy to say the results were exactly as expected, yes 4G will interfere, BUT only if you happen to have the transmitters and base stations turned up to full whack and you are within a couple of metres of the source, in most cases there will be no issues, unless of course most mobile phone users on 4G stand right next to a device for more than 15 minutes causing a polling failure, once the source of the interference has gone the next poll will go through, of course with a mesh system, there will always be other routes for the signal to get through, so the likely failure of a poll message, or any other message is unlikely.

[Oxo]

Cash, as I said.

Big pinkies will do

[AdrianMealing]

Yeah right, how much was it again

[Oxo]

12 of em to start with.

And that beer we never had

[Roger99]

Latecomer to this thread, but we have tested our Ricochet equipment at BT's Baldock facility in preparation for the 4G roll-out, i am happy to say the results were exactly as expected, yes 4G will interfere, BUT only if you happen to have the transmitters and base stations turned up to full whack and you are within a couple of metres of the source, in most cases there will be no issues, unless of course most mobile phone users on 4G stand right next to a device for more than 15 minutes causing a polling failure, once the source of the interference has gone the next poll will go through, of course with a mesh system, there will always be other routes for the signal to get through, so the likely failure of a poll message, or any other message is unlikely.

That sounds encouraging. I'm sure you are justified in saying that a mesh topology will have the best chance of surviving in a 4g environment.

What erp and bandwidth was the 4g base station running at?

One point I would slightly disagree with. When you say

in most cases there will be no issues, unless of course most mobile phone users on 4G stand right next to a device for more than 15 minutes causing a polling failure

4g is of course being promoted as a broadband data carrier, so it's likely that a laptop or smart phone might be running 4g for extended periods near to an alarm terminal. And it may even be permanently installed in an M2M (machine to machine) environment. These will be much more severe tests than occasional phone calls.

Interesting times.

[AdrianMealing]

The 4G test facility was run at various parameters from typical to worst case power output, and right across the full bandwidth, even with laptops and phones running at extended periods in reality if they are more than a meter away the disruption is likely to be minimal, you are correct in a previous post about the protocol used,, the design of the protocol is critical in minimising the impact, most well designed wireless from major manufacturers will have few problems, The biggest unknown at this point is how all of the providers will implement the service, we have only tested with BT under their conditions and test regime, other providers may not work the same way....