1 Introduction to Bluetooth v1.1 (Part I) Overview Radio Specification Baseband Specification LMP L2CAP.
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Introduction to Bluetooth v1.1 (Part I)
Overview Radio Specification Baseband Specification LMP L2CAP
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Overview an always-on, short-range radio
hookup resident on microchip initially developed by Swedish
company Ericsson in 1994 > 1000 companies have signed on
to make Bluetooth the low-power, short-range wireless standard
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Business Week, Sept. 2000 “expect Bluetooth to be installed in
billions of devices by 2005” Bluetooth standards are published
by an industry consortium known as “Bluetooth SIG (special interest group)”. IEEE 802.15.1
newer version v1.2
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Goals a universal short-range wireless
capability on 2.4 GHz band (which is globally available for unlicensed low-power uses)
In 10 meters, two bluetooth devices can share up to 720Kbps rate.
Support data, audio, graphics, and even videos.
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Capability make calls from a wireless headset eliminate cables linking computers,
printers, keyboards, and mouses hook MP3 players wirelessly remotely control AC, oven, home
devices
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General Application Category data and voice access points:
effortless wireless connection cable replacement:
normally 10 m, but can be extended up to 100 meters
ad hoc networking: building a network instantly when two
bluetooth devices meet
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Networking Capability Brief up to 8 devices can communicate
in a small network called a “piconet”
10 piconets can coexist in the same coverage range with insignificant degradation
security mechanism to protect each wireless link
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Standards Documents > 1500 pages divided into two groups:
core protocol layers, architecture, radio, timer
profile each profile specification discusses the use of
the core spec. to implement a usage model. to define a standard of interoperability two categories: cable replacement and
wireless audio
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Protocol Architecture Radio:
interface, frequency hopping, modulation, transmit power
Baseband: connection establishment in a piconet,
addressing, packet format, timing, power control
Link Management Protocol (LMP): link setup, authentication, packet size
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Logical Link Control and Adaptation Protocol (L2CAP): adapts upper-layer protocols to
baseband, connectionless service, connection-oriented service
Service Discovery Protocol (SDP): device info (service, characteristic),
service query
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Usage Models in profile documents each usage model defines a set of
protocols that implement a particular Bluetooth-based application
Fig. 15.3 illustrates the highest-priority usage models.
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Piconet piconet: the basic networking unit
one master + 1~7 active slaves Master:
determining channel and timing channel: frequency-hopping sequence timing: offset and when to transmit
the decision is based on its device address as a parameter
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Frequency Hopping among Piconets Typically, FH scheme uses carriers
spacing of 1 MHz with up to 80 different frequencies.
So, with FH, there are 80 logical channels (theoretically). When two piconets choose the same
1MHz-band, collision occurs.
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Scatternet a device in one
piconet may also exist as part of another piconet as either a master or slave in each piconet
such overlapping is called a scatternet
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Radio Specification
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Key Parameters
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Transmitter Output Powers Class 1: greatest distance (100m)
1 mW (0dBm) to 100mW (+20dBm) power control mandatory
Class 2: (10m) 0.25 (-6dBm) ~ 2.4mW (+4dBm) power control optional
Class 3: (1m) lowest power, 1mW
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Frequency Availability on 2.4 GHz in ISM band sufficient to define 79 continuous
1-MHz physical channels
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Bluetooth Products
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