I remembered I asked one of security people, what Mobile Phone Technology (MPT) mean, and unfortunately he did not know !

Now, with the help of Google I found more info about MPT:
The Path Intelligence FootPath system consists of a small number of discreet monitoring units installed throughout the centre. These units calculate the movement of consumers without requiring the shopper to wear or carry any special equipment. The units measure signals from the consumers' mobile phones using unique technology that can locate a consumer's position to within a few metres. These units feed this data (24 hours a day 7 days a week) to a processing centre, where the data is audited and sophisticated statistical analysis is applied to create continuously updated information on the flow of shoppers throughout the centre. At any time the shopping centre management can access the data via PI's secure web-based reporting system.
"Our FootPath™ technology allows us to monitor the path you take as you travel through premises belonging to any of our clients.
FootPath™ works by detecting a randomly generated, frequently changing signal from your mobile phone. This random signal is detected by a number of our units within the premises. We combine the information detected from the mobile phone signal with a proprietary mathematical algorithm developed by us. This allows us to determine your path through premises equipped with our receiver units.
Importantly, our detector units do not allow us to obtain your telephone number, to listen to any of your calls, read any SMS messages read or sent by you, or to log details of any calls or SMS messages made or received by you. Neither does any of the information received allow us to identify you or any group of individuals."

Path Intelligence
Foot Path Technology
Shopping centres track customers with mobile technology