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Introduction to
Bluetooth Book

Introduction to Bluetooth Book

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Bluetooth Sleep Modes Diagram
Sleep mode is a process used in a radio receiver where electronic circuits (such as a receiver) are temporarily deactivated or put into a low power consumption mode (such as back lighting off) to save battery energy. Bluetooth sleep modes are used to reduce the power consumption (extend the battery life) and to free the Piconet of device activity so other devices may participate in the Piconet. Bluetooth sleep modes include short one-time hold periods, periodic sniff periods, and long time park periods.

Hold Mode - is a temporary process that is typically entered into by a device when there is no need to send voice or data information for a relatively long period time. The Bluetooth hold mode is used to release the device from actively communicating with the master. This allows the devices to sleep for short periods and allows the master control device to discover or be discovered by other Bluetooth devices that want to join other Piconets.

Sniff Mode - sniffing - is a process of listening for specific types of commands that occur periodically. Sniffing is used for devices that must continuously be in contact with the master. The Bluetooth sniff mode is used to reduce the power consumption of the device as the receiver can be put into standby between sniff cycles.

Park Mode - Parking - is the process of temporarily deactivating a device to allow its active member address to be removed (probably re-assigned) and assigning communication functions to remain inactive for extended periods of time. When the master commands the slave to park, the slave will periodically wake up and look for a beacon signal from the master unit. If this beacon signal contains the address of the parked device, the device will reactivate and become part of the Piconet again. The maximum time period that can be assigned for hold, sniff, or park sleep mode is 65,440 slots (approximately 40 seconds).

This figure shows the different types of sleep modes used in a Bluetooth system. This diagram shows that the master controls the sleep modes of the devices within the Piconet. In this example, the master in the Piconet commands a PDA to one time sleep period (hold mode) for 500 msec. The master then commands the mouse in the Piconet to sleep periodically (sniff mode) for 50 msec. The master then commands the scanner to give up its active member address and wait until 10 seconds before it will again communicate with the scanner.



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Introduction to Bluetooth Book

This book explains how Bluetooth devices can locate, authenticate, discover the capabilities, and setup connections with other Bluetooth devices. Radio packet structures, modulation types, and protocols are described and explained along with Bluetooth security pairing (authentication) and privacy (encryption) processes.

$19.99 Printed, $16.99 eBook