Anti baggage theft alarm

Hi u guys, its been a while...
I am thinking of working on a small project over the winter here to kill boredom...
I was planning to make a anti theft baggage alarm, which is basically a unit which you put in your bags and it alerts you whenever you are 'x' meters(upto say 20m?) away from the bag.
I was looking at various tech thats available to use for the system like Bluetooth 4, but the problem with these would be range is not always a constant(say if I put the Transmission unit inside the bag) and connection can be dropped at anytime. So is there a some tech which could give me a fail safe method? Or maybe the safest bet among the tech available?
What are the other technologies I should look at? Rfid(Very low range) or zigbee maybe?

Is there anyone here who has worked on something similar or own a device similar to these? Any help would do... I am just looking for new directions... :slight_smile:

Thanking you guys in advance... :slight_smile:

A quick question, will these items of luggage ever go on board an aircraft?
if so, be very careful with RF transmissions as this is not only a possible safety issue but I suspect you will also get pulled aside at many airports due to a piece of luggage with lots of electronics bits and pieces inside it.

UnoDueTre:
A quick question, will these items of luggage ever go on board an aircraft?
if so, be very careful with RF transmissions as this is not only a possible safety issue but I suspect you will also get pulled aside at many airports due to a piece of luggage with lots of electronics bits and pieces inside it.

hmm... havent thought of that... but it would ideally be a small Tx unit. and the base station could be a keychain or a mobile phone running an app...

This topic - monitor how far is X is from Y - seems to come up fairly often and there is no simple "general purpose" solution. There are options if you have line-of-sight but not for a situation like luggage in an airport or railway station.

The gadgets like these are already on the market with coin like sensors which are standalone with BLE 4.0 utilised in the design to not run the coin cell these sensors work on then coupled with an app Android or iOS and even windows phone app ,the app generates an alarm if the proximity to any of the BLE tags is lost.
last Year a California based startup made a Million dollars by developing this and then many others came up!

@Nishant..
I know its already out there... but point is, is it accurate enough to detect distances and all? I have seen tag and so on which helps you find the stuff which are in a vicinity... I want to have a device which would cause an alarm if you move out of a region. It needs to consistantly do that with no false triggers or droppages... I was wondering if it could be done with this accuracy...

There needs to be a lot of clever programming to achieve it because technically the way even these million dollar making people use that bluetooth rssi signal as the proximity calculation basis which if you ask any experienced developer here would be condemned as a choice for knowing the proximity but stilk these gadgets employ this way and it works so it should be some clever algorithmic code back there.

Rssi is very easily miss addressed with metal gates aand even tree leaves and magnetic zones created by high tension electricity flowing wires.