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Low Rate Wireless Personal Area Networks
Wireless Communications Low Rate Wireless Personal Area Networks Objectives • Describe a wireless personal area network (WPAN) • List the different WPAN standards and their applications • Explain how IrDA, Bluetooth, and ZigBee work • Describe the security features of low-rate WPAN technology What is a WPAN? • Wireless personal area network (WPAN) – Group of technologies that are designed for shortrange communications – Eliminates the need for wires or cables to interconnect multiple devices • Applications for WPAN technology include: – – – – Synchronizing PDAs, cellular, and Smartphones Home control systems (smarthome) Cordless telephones Portable device data exchange What is a WPAN? (continued) • Applications for WPAN technology include (continued): – Industrial control systems – Location — smart tags used to locate people at home or at the office – Security systems – Interactive toys – Inventory tracking • Advantages – WPAN devices use very little power – Short range helps maintain security and privacy Infrared WPANs (IrDA) • Most common infrared connection today – Based on the IrDA specifications • IrDA specifications – Define both physical devices and network protocols • IrDA devices’ characteristics – Provide walk-up connectivity – Provide a point-to-point method of data transfer • Between only two devices at a time Infrared WPANs (IrDA) (continued) Infrared WPANs (IrDA) (continued) • Serial Infrared (Version 1.0) – Designed to work like the standard serial port on a PC – Uses a UART (Universal Asynchronous Receiver/Transmitter) • Microchip that also controls a computer’s serial interface • Fast Infrared (FIR) (Version 1.1) – Extends the data rate to Mbps – When two IrDA devices first communicate • They both transmit using SIR • Then they shift to FIR speed RF WPANs • Offer functionality beyond that of IR devices • Include – Bluetooth – 802.15.4 (ZigBee) IEEE 802.15.1 and Bluetooth • Industry specification – Bluetooth Special Interest Group (SIG) • Defines small-form-factor, low-cost wireless radio communications • IEEE licensed this wireless technology – To adapt and copy a portion of the specification as the base material for 802.15.1 • 802.15.1 standard – Approved in March 2, 2002 – Fully compatible with Bluetooth version 1.1 Bluetooth Protocol Stack • Bluetooth RF layer – Defines how the basic hardware that controls the radio transmissions functions – Data bits (0 and 1) are converted into radio signals and transmitted • Radio module – – – – A single radio transmitter/receiver (transceiver) Only hardware required for Bluetooth to function Bluetooth can transmit at a speed of up to Mbps Bluetooth version 2.0 transmits at or Mbps 10 Bluetooth Protocol Stack (continued) 11 Bluetooth Protocol Stack (continued) 12 Bluetooth Protocol Stack (continued) 13 Bluetooth Protocol Stack (continued) • Network topologies (continued) – Scatternet • Group of piconets in which connections exist between different piconets – To communicate in each different piconet • Device must use the master device address and clock of that specific piconet – Bluetooth device can be a slave in several piconets • But can be a master in only one piconet – A master and slave can switch roles in a piconet 14 Bluetooth Link Manager Layer (continued) • Link between Bluetooth devices (continued) – Bluetooth power usage (continued) • Power-saving modes – Active – Sniff – Hold – Park 15 Low Rate WPAN Security • Security should be of little concern with WPANs • One of the most serious concerns is social engineering • Designing security in WPANs – Much more difficult task than in other networking technologies • Public key infrastructure (PKI) – Unique security code, or key, provided by a certificate authority • Certificate authority – Private company that verifies the authenticity of users 16 Security in Infrared WPANs • Limited to the line-of-sight characteristic of this type of connection • IrDA specification makes no provision for encrypting data or protecting the connection – Users may encrypt a file before exchanging it • IrDA devices support open access – So that anyone can transmit files without first notifying the device’s owner • Open access can be a major security concern • Bluetooth provides security at the LMP layer – Using authentication • Authentication is based on identifying the device itself • Authentication scheme is a challenge-response strategy • Encryption is the process of encoding communications – And ensures that the transmissions cannot be easily intercepted and decoded 17 Summary • The most common infrared connection today is based on the IrDA standard – IrDA devices cannot send and receive at the same time – IrDA is easy to use • Bluetooth is a wireless technology that uses shortrange radio frequency (RF) transmissions – Supported by over 2,500 hardware and software vendors 18 ... Describe a wireless personal area network (WPAN) • List the different WPAN standards and their applications • Explain how IrDA, Bluetooth, and ZigBee work • Describe the security features of low- rate. .. ZigBee work • Describe the security features of low- rate WPAN technology What is a WPAN? • Wireless personal area network (WPAN) – Group of technologies that are designed for shortrange communications... Bluetooth Special Interest Group (SIG) • Defines small-form-factor, low- cost wireless radio communications • IEEE licensed this wireless technology – To adapt and copy a portion of the specification