A SYDNEY start-up believes Bluetooth low-energy technology like Apple’s iBeacon could act as a personal digital concierge as it prepares to wire up GPT Group, which has $16.7 billion worth of assets. The nascent technology could further proliferate when AirService begins deploying mobile ordering solutions for an undisclosed restaurant chain, said to be one of Australia’s largest. AirService has a mobile app for ordering food and beverages that will be used by large property developers such as GPT and LendLease so workers do not have to leave the office to get fed.