Advice on Ajax Intruder Alarm system

[benawhile]

Before I install security cameras I want to set up an intruder alarm system. In spite of there being a myriad of manufacturers and installers I have been able to exclude a large amount of them because of my requirements and limitations.
I do not want a monitored system and do not want to pay for installation, in fact professional installation isn’t feasible at present because we have just embarked on major alterations to the house.
I like the idea of a system hub that communicates to and receives from a mobile phone app both by Ethernet or GPRS/SIM. My Internet cable is quite exposed and could easily be cut so SIM backup could be useful.
I also want something with central keyboard control rather than always having to control via the app.

Yale, for example don’t seem to do GPRS. ERA Response systems “HomeGuard” dual channel is wifi only and not Ethernet.

I have tried to understand the various communication methods from home to mobile phone and have devised this block diagram and would welcome comments on whether it is roughly accurate:

Sensor>Hub>Ethernet/Wifi >Internet>local Wifi >Phone>App

Sensor>Hub>Ethernet/Wifi >Internet>GPRS >mobile data >Phone>App

Sensor>Hub >SIM >mobile phone network >mobile data >Phone>App

I am quite impressed by Ajax equipment as supplied by DDS and wondered if anyone would comment on them. They also supply UniView cameras which share the same app.

I have also found this mini system below which might meet my needs, apart from not having Ethernet connection, but would welcome comments:

GSM/3G & WIFI Security Alarm System, Wireless Smart Home Burglar Security System, Large Touch Screen, 99 Wireless Defense Zones, Works with Smart Socket, APP Control, with Wireless Siren: Amazon.co.uk: DIY & Tools

I am in UK

 

[Old Timer]

I like the simply safe alarms, they might be worth looking at. I don't know if they have service in the UK?

I use them for alarms in outbuildings like tower sites and communications huts.
The only one I have had that failed ended up getting replaced for free 4 years after I bought it.

 

[benawhile]

I should have added that this will be for a medium sized detached property

 

[Old Timer]

Looking at simply safe, I don't see where they talk about anything across the pond.

 

[benawhile]

Home Security Systems & Products | SimpliSafe

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simplisafe.co.uk

Looks like we have then here, will look

 

[DanielUK]

I’m in the UK and have self installed the Ajax system.

It’s Ethernet, WiFi and 2x SIM cards from different network providers.. 1 goes down the other would hopefully stand up.

I’ve found it to be flawless. Totally user friendly and expandable as an when/if your needs ever required it. I hide a motion sensor in my car too so when it’s parked up if someone tries nicking it, it sets off the house alarm as well as it’s own alarm/immobiliser.

Loads of things you can do with it.

My house is a 2500m2 property so not small and it has really good coverage.