ormed by the gate- way device that connects the two networks. Nonce: A random number used once and then discarded, for example as the seed for an algorithm used to determine encryption or authentication keys. Omnidirectional Antenna (Omni): An omnidirectional antenna has a 360 degree beamwidth in the horizontal plane (perpendicular to the axis of a vertically mounted antenna), and is used when transmission and reception is needed in all radial directions. The gain of an omni can be increased at the expense of reducing the vertical beamwidth. Glossary Orthogonal Frequency Division Multiplexing (OFDM): OFDM is a multiplexing technique in which a data stream is split into a number of parallel streams of lower bit rate which are modulated onto a set of subcar- riers and transmitted concurrently. The characteristic of orthogonality refers to the frequency separation of the subcarriers which is chosen to reduce inter-carrier interference. Packet Binary Convolution Coding (PBCC): Packet Binary Convolution Coding is a data coding and modulation scheme developed by Texas Instruments as a proposal for the 802.11g standard. OFDM was selected in preference to PBCC as it delivers 54 Mbps compared to the 33 Mbps achievable with PBCC. Pairing: The initial step in creating a link between Bluetooth devices when a PIN is entered into both devices. Pair-wise Temporal (or Transient) Keys: Encryption keys that are derived as part of a device authentication process and used by both devices to encrypt data traffic for the duration of the connection. Personal Computer Memory Card International Association (PCMCIA): The Personal Computer Memory Card International Association was formed in 1989 to define standards for portable computer expansion cards. PCMCIA cards are now known as PC cards. Piconet: An ad-hoc collection of devices in a PAN with one device acting as a master and the others as slaves. The master device sets the clock and other link parameters such as a FHSS hopping pattern. In Bluetooth piconets, each master can connect to