ver the full range of technical capabilities present in the final user group - from the most technically savvy, whose performance expectations will be hardest to meet, to those who may be less demanding on performance but will have a natural focus on ease of use. Taking account of a wide diversity of views on how well the solution meets the full range of user requirements may make the implementation task more challenging, but will ultimately result in wider user acceptance of the end result. Wireless PAN Security Although a wireless PAN will generally have a more limited range than a WLAN (with the possible exception of ZigBee networks), ensuring security will remain an important implementation issue, since most wireless PAN technologies are potentially vulnerable to a variety of security threats. The following sections summarise the security features and known vulnerabilities of various PAN technologies, and provide guidance on security set-up during implementation. Bluetooth Security Bluetooth Security Overview Bluetooth includes comprehensive security measures designed to ensure that access to services is protected and only granted to another device after appropriate authorisation. Three types of service security levels are defined, as shown in Table 11-4. The first step in the process of establishing a secure Bluetooth connection is authentication, which occurs after the initial pairing and results in the Implementing Wireless PANs Table 11-4: Bluetooth Service Security Levels Security Service type Security level Open services These services can be accessed by any device. There are no security requirements and authentication and encryption are bypassed. Authentication only These services can only be accessed by services authenticated devices. Authentication and These services may only be accessed by trusted authorisation services devices. creation of a semi-permanent authentication key that is shared by the two devices. Authorisation is the second step, and may be required before a device will give another de