Abstract: A method of and system for providing a service to a user includes receiving (500), by a first service provider terminal (132(i)), an account number (PAN; DAN) stored in a chip of a mobile device (102; 112; 103), which mobile device is configured to be used in open-loop financial transactions; checking (501), by the first service provider terminal (132(i)) if the received account number (PAN; DAN) is present on a closed-loop list, the closed-loop list identifying account numbers for which a closed-loop service is supported; if so, forwarding (503), by the first service provider terminal (132(i)), the received account number to a service provider server (134(j)) configured to either approve or deny, respectively, the closed-loop service and receiving, from the service provider server (134(j)), either an approval signal (508) or a denial signal (506).

Abstract: In a server system, a computer-implemented method of initiating a proximity-based communication protocol involving a first and one or more second client devices. For each of plural candidate second devices location coordinates are retrieved and an associated axis aligned bounding box AABB is calculated. When AABB of such candidate second devices overlap with an AABB for the first device, the candidate is presented to the user of the first device. Next, a selection of one or more candidate second devices is received from the first device and causing the protocol to be initiated between the first device and the one or more selected candidate second devices.