rring, creating or deleting files or folders. Headset profile Enables audio data transfer between a device such as a mobile phone or a PDA and a wireless headset. Dial-up networking profile Enables a dial-up networking link between a PDA or other device and a remote network. LAN access profile Enables a device to gain access to network resources such as storage or printers by using point-to-point protocol (PPP) to connect to another device that is already in a LAN. Wireless PAN Standards its effectiveness in common PAN tasks, such as telephony and short-range networking has resulted in it establishing a strong position among the available PAN options. Protocol Stack The Bluetooth protocol stack is illustrated in Figure 10-2. Above the Bluetooth radio (PHY layer), the Baseband, link manager protocol (LMP) and logical link control and adaptation (L2CAP) protocols correspond to the Data Link (LLC + MAC) layer of the OSI model. The following sections describe the PHY and Data Link layers, and outline the higher level protocols up to RFCOMM and service discovery protocol (SDP). The Bluetooth stack also included protocols adopted from other sources, such as OBEX an object exchange protocol adopted from IrDA (see the Section "IrDA Optional Protocol Stack, p. 284") and WAP (Wireless application protocol) - developed by the WAP Forum to support the delivery of Internet content over wireless links, primarily to mobile phones. Including WAP in the Bluetooth stack enables the reuse by Bluetooth profiles of software from the wireless application environment developed for WAP phones. Applications TCP/IP Bluetooth Host Protocol Stack RFCOMM (Software) Logical Link Control and Adaptation Protocol (L2CAP) Host Controller Interface (HCI) Host Controller Interface (HCI) firmware Bluetooth Host Controller Link Manager Protocol (LMP) Audio (Firmware and Hardware) Baseband / Link Controller (LC) Bluetooth radio (PHY) Figure 10-2: Bluetooth Protocol Stack Chapter Ten The Bluetooth Radio At the physical layer, Bluetooth uses the IEEE 80