When you turn on your cell phone, the first thing you see is the message looking for service. During the delay to follow your phone is busy locating the network and negotiating admission to it. This is called programming service discovery interfaces; it is not easy, but it's a prerequisite for all telecom services. This title teaches developers how to do it right. It explains and compares competing platforms: Bluetooth, Jini, Salutation, SLP and UPnP.