Concept Request Automatic connection of customer smart phone to merchant tablet not via internet

Project description This is a concept request to identify how to automatically connect a customer using a smart phone to merchant using a table in close proximity. Scenario Customer with App AndrewsConnect(Customer Version) walks into Store Phone connects to Merchant Tablet using App AndrewsConnect(Merchant Version) Merchant Tablet displays Customer Name in list time entered so Merchant can greet the customer Merchant will enter value if a purchase is made by the Customer or customers feedback Details of data recorded somewhere cloud or tablet your opinion please. Note: The merchant does not have Internet so the phone and table need to connect by another method. Merchant needs to use a tablet is Bluetooth an option? What I need to know is this possible and what technology will be used approximate cost of simple app. Need a quote to provide me with solution to my concept I will write a specification for an App AndrewsConnect(Customer/Merchant Versions)