Enhancing the Bluetooth Service Discovery Protocol

Abstract

Bluetooth Service Discovery Protocol (SDP) enables a client application on a device to discover information about services on other Bluetooth devices. Every service is represented by a profile, identified by a 128-bit Universally Unique Identifier (UUID). A match occurs on a peer device if and only if at least one UUID specified by the client is contained in one or more of its service records. We believe that the advantages of UUID-based matching to support service discovery are restricted to ad-hoc Bluetooth networks consisting of resource constrained devices. The more common case for applications using Bluetooth networks, is the existence of one or more resource rich devices (e.g., the Compaq iPAQ) in the network. This calls for a matching mechanism that uses semantic information associated with services and attributes to decide the success or failure of a query. We present an enhanced version of Bluetooth SDP that supports semantic matching and provides service registration. We evaluate the performance of this enhanced version of SDP and compare it with regular SDP. We show that enhanced SDP performs comparably to regular SDP in terms of Round Trip Time and matching time.