10 3,1998
`
`Bluetooth—The universal radio interface for ad hoc, wireless connectivity
`_
`_
`_
`Internet directory services with click-to-dial
`
`'
`
`JambaIa—|ntel|igence beyond digital wireless
`
`ERION—Ericsson optical networking using WDM technology
`
`Access 910 system
`
`
`
`
`5-! '[ ._'I
`-_j
`Samsung Ex. 1108A iifi
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:20)
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`-
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`_I.
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`'- "ll
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`

`
` EW
`
`
`
`The telecommunications
`
`technology journal
`
`
`
`
`
`
`
`
`
`The purpose of Eticsson Review is to
`report on the research, development
`and production achievements made in
`telecommunications technology at
`Ericsson. The journal is published in
`English and Spanish and distributed
`quarterly to readers in more than 130
`countries.
`
`
`
`
`
`
`
`
`Address:
`
`
`
`Telefonaktiebolaget LM Eticsson
`S-126 25 Stockholm, Sweden
`
`Tel: +46 8 719 00 00
`
`Fax: +468 6812710
`
`Internet address:
`
`http:Hwww.ericsson.comiReview
`
`Publisher: Lats A. Stfilbetg
`
`
`
`
`
`
` Editorial board: Hans Alberg, Greget
`Berg, Torn Boothe, Mikael Back,
`Philippe Charas, Jonas Hetmansson,
`Anders I-Iidrnark, Lena Krogstad, Filip
`Linclell, Bo Malrnberg, Mats Nilsson,
`Eric Peterson, Goran Rassmuson,
`
`Contents
`
`Biuetooth—The universal radio interface for ad hoc,
`
`wireless connectivity
`
`inside
`Imagine a cheap, powenefficient radio chip that is small enough to fit
`any electronic device or machine and that provides local connectivity. Blue-tooth
`is a universal radio interface in the 2.45 GI-lz frequency band that enables
`portable electronic devices to connect and communicate witelcssly via rm’ our
`networks.
`Page 110
`
`Internet directory services with click-to~dial
`
`Internet directory services make available vast resources of the Internet, helping
`users to save valuable time in finding names, e-mail addresses, and so forth. Click-
`to—dial services allow users to invoke calls by clicking on the phone number they
`retrieve using directory services. Ericsson's solution sets up and transmits calls via
`the PSTN, but it is equally compatible with VoIP.
`Page 118
`
`Jambala—lnteI|igence beyond digital wireless
`ambala is the ncxt— eneration 22
`lication latform that o erators need to rovide
`3
`PP
`P
`P
`
`new, high—value services in an increasingly segmented end-user market. Jambala
`provides a unique combination of availability, reliability, scalability and Internet
`reatliness—all using commercially available hardware.
`Page 126
`
`ERION—Ericsson optical networking using WDM
`technology
`'
`Ericsson maintains a simple, pragmiitic approach to networking as they further ex-
`plore and exploit dense WDM technology and optical networking. Ericsson's next-
`generation transport—network technology—ERION—enables operators to derive
`maximum benefit from investments in client technology, while simplifying net-
`
`works and improving traffic protection and routing functionality.
`
`Page 132
`
`Access 910 system
`
`Ericsson's Access 910 is at general-purpose, access—network system that provides
`PSTN, Internet, VOIP, ATM, and switched video broadcast capabilities to 21 wide
`ran e of service networks. The su
`ort it
`rovides for aractical, cost-effective mi-
`8
`PP
`P
`l
`ration from narrowband to broadband services makes it ideal for
`resent-da and
`8
`Y
`future telecom environments.
`Page 133
`
`P
`
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:21)
`Samsung Ex. 1108A p. 2
`
`107
`
`
`
`
`
`Michele Schmidt, Ole Segtnan, Sture
`Sjtistrcim, Bengt Stavenow,
`I.ats~
`Gunnar Sundin, Peter Svéird
`
`Editor: Eric Peterson
`
`Production manager: Eva Katlstein
`
`Layout: Paues Media, Stockholm
`
`Printer: Ljungforetagen, Otebto
`
`ISSN: 00i4«01?1
`
`Volume: 75, 1998
`
`
`
` cover: Bltletootlt technology substitutes a
`universal sl1ort—range radio link for t|1e
`
`many proprietary cables that are presently
`used for connecting devices. But more than
`this, Bluetooth radio technology provides a
`universal bridge to existing data networks.
`a peripheral interface. and :1 mechanism for
`forming small at! bar groupings of connect-
`ed devices away from fixed network infra-
`structures.
`
`
`
`
`
`
`
`
`
`
`
`© Telefonaktiebolaget LM Eticsson
`
`Erlcsson Review No. 3. 1993
`
`
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`
`
`

`
` Bluetooth—The universal radio interface for
`
`ad hoc, wireless connectivity
`
`Jaap Haartsen
`
`Bluetooth is a universal radio interface in the 2.45 GHz frequency band that
`enables portable electronic devices to connect and communicate wirelessiy
`via short-range, ad hoc networks. Each unit can simultaneously communi-
`cate with up to seven other units per piconet. Moreover, each unit can
`simultaneously belong to several piconets.
`Bluetooth technoIogy—whlch apart from Ericsson, has gained the support
`of Nokia, IBM, Toshiba, Intel and many other manufacturers—eiiminates the
`need for wires, cables and connectors for and between cordless or mobile
`phones, modems, headsets, PDAs, computers, printers, projectors, local
`area networks, and so on, and paves the way for new and completely differ»
`ent devices and applications.
`Before guiding us through frequency-hopping technology and the channel,
`packet and physical-link definitions that characterize the Bluetooth air inter-
`face, the author briefly describes the conditions that led up to the develop-
`ment of Bluetooth. He then acquaints us with the networking aspects of
`Bluetooth technology, describing piconets and scatternets, connection pro-
`cedures, and Inter-piconet communication.
`
`Imagine a cheap, power—efficient radio chip
`that is small enough to fit inside any elec-
`t ran it device or rnacliine, that provities local
`connectivity, and that creates a (worldwide)
`i"I'll(‘|'0-'S(.‘€ill'.‘ web. Wliat applications might
`you use it in?
`lo 1994, Ericsson Mobile Communica-
`tions AB in Lund, Sweden. initiated 31. study
`to investigate the feasibility ofa low-power,
`low—cost
`radio interface between rnobilt'
`
`phones and their accessories. The intention
`
`was to eliminate cables between phones and
`PC cartls, wireless headsets, and so forth.
`The study was part ofa larger project that
`investigated multi-communicators
`con-
`nectecl to the cellular network via cellular
`telephones. The last link in the connection
`between a cornmunicator and the cellular
`network was :1 s|1ort—r:mge radio link to the
`phone-—-thus, the link was called the multi-
`communicatot link or MC link. As the MC
`link project progressed, it became clear that
`there was no limit to the kinds of applica-
`tion that could use a short—range i"JI:ll() link.
`Cheap, short-range radios would makewire-
`less communication between portable de-
`vices economically feasible.
`Current portable devices use infrared
`links (lrDA) to communicate with each
`other. Although infrared transceivers are in-
`expensive, they
`I have limited range (typically one to two
`meters);
`0 are sensitive to direction and require
`direct line-of-sight;
`0 can in principle only be Lrsed between two
`devices.
`
`By contrast, radios have mtlch greater range,
`can propagate around objects and through
`various materials, and connect to many de-
`vices simultaneously. What is more, radio
`interfaces do not require user interaction.
`in the beginning of I99?! when design-
`ers had already begun work on an MC link
`
`LAN
`
`Headset
`
`Access point
`
`A , — 2;’. -' ‘V
`
`E
`
`Mobile phone
`
`.
`
`Cellularnetwork
`
`
`
`MOUSE
`
`Printer
`
`Figure 1
`User model with local wireless connectivity.
`Applications envisioned for the near future.
`
`"*1. -
`Fmnel
`
`110
`
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:22)
`Samsung Ex. irrosiserseoo-3-1993
`
`
`

`
`
`
`Box A
`Abbreviations
`
`ACL
`ARQ
`CVSD
`DSP
`FEC
`FH
`FSK
`HEC
`HPC
`lrDA
`ISM
`MAC
`MC
`PC
`PDA
`RF
`SCO
`
`SIG
`TDD
`TDM
`
`Asynchronous connectioniess
`Automatic retransmission query
`Continuous variable slope delta
`Digital signal processor
`Forward error correction
`Frequency hop
`Frequency shift keying
`Header error correction
`Handheld personal computer
`Infrared Data Association
`industrial Scientific Medical
`Media access control
`Multicommunicator
`Personal computer
`Personal digital assistant
`Radio frequency
`Synchronous connection-
`oriented
`Special interest group
`Time division duplex
`Time division multiple:
`
`transceiver chip, Ericsson approached other
`manufacturersofportableclevices to raise in-
`terest in the teChnology—for the system to
`succeed, a critical mass of portable devices
`must use the short—range radio. In Febrtlaty
`1998,
`five promoters-—-Ericsson, Nokia,
`IBM, Toshiba and lntel—formed a special
`interest group (SIG). The idea was to achieve
`a proper mix of business areas: two market
`leaders in mobile telephony,
`two market
`leaders in laptop computing, and a market
`leader
`in
`core, digital-signal-processor
`(DSP) technology. 011 May 20 and 21,1998.
`tl1e Bluetooth consortium announced itself
`
`to thegeneral public from London. England;
`San_]osc.CaliFornia;anI:l Tokyo,_Iapan.SinCe
`then, several companies have joined as
`adopters of the technology (Box B).
`to
`The purpose of the Consortium is
`establish a riefwfo standard For the air inter-
`face and the software that controls it,
`thereby ensuring interoperability between
`devices ofdifferent mantlfacrurers. The first
`
`products to use MC link technology will
`emergent theend of1999in mobile phones,
`notebook
`computers
`and
`accessories
`(Figure 1.).
`
`Box B
`
`The Bluetooth consortium—prc-moters and adopters
`The promoters of the Bluetooth* consortium formed a special interest group [SIG] at Ericsson
`Inc.. Research Triangle Park. North Carolina. on February 4, 1998.
`The consortium was announced to the public on May 20 and 21. 1998. Many companies have
`since joined the consortium as adopters of the technology {status as of July 11. 1993):
`
`Promoter
`Promoter
`Promoter
`Promoter
`Promoter
`
`Ericsson
`Intel
`IBM
`Nokia
`Toshiba
`3Com
`Axis
`BreezeCOM
`Casio
`Cambridge consultants-:Ltd.
`CETECOM GmbH
`Cirrus Logic
`Compaq Computer Corp.
`Convergence Corporation
`Dell Computer Corp.
`lnnoi.al:is Corporation
`Jeeves Tolecom Ltd.
`Lucent Technologies UK Ltd.
`Metricom
`Motorola
`NeoParadigm Labs. Inc.
`
`Ericsscn Review No. 3. 1998
`
`Plantronics
`Psion
`Puma Technologies
`Quadriga
`Qualcomm, Inc.
`Samsung Electronics Ltd.
`Siemens Forsvarsystem A/S
`Symbian
`Symbionics Ltd.
`Tspan System
`Temic Semiconductor
`TDK
`TTP Communications Ltd.
`Universal Empowering Technologies
`VLSI Technology, Inc.
`Xircom
`
`'
`
`* The name. Bluetootn, was taken from i-lar-
`ald Blétand. a Danish Viking king from the
`early Middle Ages.
`
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:23)
`Samsung Ex. 1108A p. 4
`
`111
`
`
`
`

`
`Figure 2
`Frequency-hop/time-dlvision-duplex channel.
`
`The Bluetooth air interface
`
`The focus of user scenarios envisioned for
`
`typically on
`firsbgeneration products is
`traveling business people. Portable devices
`that contain Bluetooth radios would enable
`them to leave cables and con ncctors at home
`(Box C). Before the air interface for Blue-
`tooth could be designed, however, certain
`requirements had to be settled:
`0 The system must operate worldwide.
`0 The connection must support voice and
`clat“a—For instance, for multimedia appli-
`cations.
`" The radio transceiver must be small and
`
`operate at low power. That is, the radio
`must fit into small, portable devices, such
`as mobile phones, headsets and personal
`digital assistants (PDA).
`
`Box C User scenarios
`
`Three-in-one phone—use the same phone
`everywhere
`When you are at the office, your phone func-
`tions as an intercom [no telephony charge].
`At home,
`it functions as a cordless phone
`(fixed-line charge). when you are on the move,
`it functions as a mobile phone {cellular
`charge].
`
`Internet bridge-—-surfthe Internet regardless
`of the connection
`Use your portable PC to surf the internet any-
`where, regardless of whether you are con-
`nected wirelesslythrough a mobile phone (cel-
`lular) or through a wired connection {PSTN,
`ISDN, LAN, XDSL).
`
`Interactive conference—connect every par-
`ticlpant for instant data exchange
`In meetings and at conferences. you can
`share infonnation instantly with other penici-
`pants. You can also operate a projector
`remotely without wire connectors.
`
`The ultimate headset—a cordless headset
`keeps your hands free
`Connect a headset to your mobile PC or to any
`wired connection and free your hands for more
`important tasks at the office or in your car.
`
`PC
`the briefcase. When your portable
`receives an e-mail message. you will be noti-
`fied by your mobile phone. You can also use
`the phone to browse incoming e-mail and read
`messages.
`
`Forbidden message [hidden computing 2)
`Compose e-mail on your PC while you are on
`an airplane. when you land and are allowed
`to switch on your mobile phone, the messages
`are sent immediately.
`
`Automatic synchronization (hidden
`computing 3)
`Automatically synchronize your desktop com-
`puter, portable PC. notebook (PDA or HPC) and
`mobile phone. As soon as you enterthe office,
`the address list and calendar in your notebook
`automatically updates the files on your desk-
`top computer or vice versa.
`
`Instant postcard—send photos and video
`clips Instantly from any location
`Connect a camera cordlessly to your mobile
`phone or to any wire-bound connection. Add
`comments from your mobile phone. a note-
`book, or portable PC and send them instant-
`ly to a recipient anywhere in the world. Suit-
`able for professional and personal use.
`
`Portable PC speakerphone
`Connect cordless neadsets to your portable
`PC and use it as a speakerphone regardless
`of whether you are in the office, your car, or
`at home.
`Briefcase trick (hidden computing 1}
`Access email while your portable PC is still in
`
`cordless des|ttop—conneot all peripheral
`tools to your Pt: or the LAN
`Connect your desktop/laptop computer cord-
`lessly to printers. scanners and the LAN.
`Increase your sense of
`freedom through
`cordless mouse and keyboard connections to
`your PC.
`
`112
`
`License-free hand
`
`the required Fre-
`To operate worldwide,
`quency band must be available globally.
`Further, it must be liccnsc-free and open to
`any radio system. The only Frequency band
`that
`satisfies
`these
`requirements
`is
`at
`2.45 GH'z.—thc
`lr1dustrial—Scicntific—
`Medical (ISM) band, which ranges from
`2,400 to 2,483.5 MHZ in the US and F.u-
`rope(or1ly parts ofthis band are available in
`France and Spain), and from 2,471 to
`2,497 MHZ in japan. Consequently,
`the
`system can be I.IStZ'I'.l worldwide, given that
`the radio transceivers cover the frequency
`band betwccn 2;’-l()U and 2,500 MHz and
`that they can select the proper segment in
`this band.
`
`Frequency hopping
`Since the ISM band is open to anyone, radio
`systems operating in this band must cope
`with several unpredictable sources of inter-
`ference. such as baby monitors, garage door
`openers, cordless phones and microwave
`ovens (the strongest source of interference).
`Interference can be avoided rising an adap-
`tive scheme that finds an unused part ofthe
`spectrum, or it can be suppressccl by means
`ofspcctrum spreading. In the US, radios op-
`erating in the 2.45 GHz ISM band are re-
`quired to apply spectrum-spreading tech-
`niques if their transmitted power levels ex-
`ceed 0 dBm.
`Bluctooth radios use frequency-hop (PH)
`spread spectrum, since this technology bet-
`ter supports low—cost, low-power radio im-
`plementations. Frcquency—l1op systems di-
`vide the frcqttency band into several hop
`cltannt.-Is. During a connection, radio trans-
`ccivers hop from one channel to another in
`a pSl:uCl0—1‘ai'lCl0m fashion. The instanta-
`neous
`(hop)
`bandwidth
`is
`small
`in
`_. frequency-hop radios, but spreading is usu-
`allyobtaincdovrrthccntire frequency band.
`This results in low—cosr, narrowbancl trans—
`ccivcrs with maximum immunity to inter-
`ference. Occasionally,
`interference iams a
`hop channel,
`causing Faulty reception.
`\X/hen this occurs, c-rror—corrcction schemes
`in [he link restore bit errors.
`
`channel definition
`frequency-
`a
`use
`Bluctooth
`channels
`hop!time-division—cluplex(FHlTDD)SCh3""‘3
`(Figure 2), The channel
`is divided into
`625 ps intervals—-called slots—-where a dif-
`fercnt hop Frequency is used for each slot.
`This gives :1 nominal hop rate of 1 ,6U0 l10P5
`per second. Ont: packet can be transmitted
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:24)
`Samsung Ex. trros1selr.W5*°-3-199“
`
`

`
`Hop selection
`
`*
`
`Phase
`SEQUENCE
`
`—- Hop
`
`Offset
`
`Figure 3
`
`
`Hop selection scheme: In the selection box,
`the master identity selects the sequence,
`and the clock selects the phase.
`combined. they give the hop carrier to be
`used.
`
`per intervalfslot. Subsequent slots are alter-
`nately used For transmitting and receiving,
`which results in a TDD scheme.
`
`Two or more units sharing the same chan-
`nel form a piconet, where one unit acts as a
`master, controlling traffic on the piconet,
`and the other units act as slaves. The
`
`frequency-hop channel is determined by the
`fi'eqI.iency—hop sequence (the order in which
`hops are visited) and by the phase in this se-
`quence. In Bluetooth, the sequence is de-
`termined by the identity ofthe piconet mas-
`ter and phase is determined by the master
`unit's system clock (Figure 3). In order to
`create the master clock in the slave unit, the
`slave may add an offset to its own native
`clock. The
`repetition
`interval of
`the
`frequency—hop sequence, which is very long
`(more than 23 hours), is determined by the
`clock. If every participant on a given chan-
`nel uses the same identity and clock as input
`to the hop-selection box, then each unit will
`consistently select the same hop carrier and
`remain synchronized. Every piconet has a
`unique set of master parameters which cre-
`ate a unique channel.
`The channel makes use of several, equal-
`ly spaced,
`l MI-I2 hops. With Gaussian-
`shaped frequency shift keying {FSK) modu-
`lation. a symbol rate of 1 Mbitfs can be
`achieved. In countries where the open band
`is 80 MHZ or broader, 79 hop carriers have
`been defined. In countries where the band
`is narrower Uapan, France, and Spain), only
`23 hop carriers have been defined (Table 1).
`On average, the frequencyvhop sequence vis-
`its each cartier with equal probability.
`
`Packet definition
`
`In each slot, :1 packet can be exchanged be-
`tween the master unit and one of the slaves.
`
`Packets have a fixed format (Figure 4). Each
`packet begins with a 72-bit access code that
`is derived from the master identity and is
`unique for the channel. Every packet ex-
`changed on the channel is preceded by this
`access code. Recipients on the piconet com-
`pare incoming signals with the access code.
`If the two do not match, the received pack-
`ct is not considered valid on the channel and
`the rest of its contents are ignored. Besides
`packet identification, the access code is also
`used for synchronization and compensating
`for offset. The access code is very robust and
`resistant to interference. Correlation ofthe ac-
`
`cess Code by recipients provides similar pro-
`cessing gains as direct-sequence spreading.
`A header trails the access code. It contains
`
`important control
`
`information, such as a
`
`Ericsson Review No. 3. 1993
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`llPeak data rate
`
`Parameters
`Modulation
`
`RF bandwidth
`F band
`RF carriers
`Carrier spacing
`Peak TX power
`
`Values
`GFSK. ii 5 0.35
`1 Mbit/s
`220 kHz (—3dB), 1 MHz {-20 dB)
`2.4 GH2. ISM band
`23/?9
`1 MHZ
`S 20 dBm
`
`three-bit media-access-control (MAC) ad-
`dress, packet type, How control bits, bits for
`the automatic—retransmission-query (ARQ)
`scheme and a header-error-check (HEC)
`field (Figure 5). The header, whose length
`is fixed at 54 bits, is protected bya one-third
`rate forward-erroncorrection (FEC) code.
`Payload may or may not trail the header.
`The length of the payload may vary from U
`to 2,745 bits.
`To support high data rates, mI.1lti—sloI:
`packets have been defined. A packet can
`cover one slot, three slots, or five slots. Pack-
`ets are always sent on a single—hop carrier.
`For multi»slot packets, the hop carrier is
`used as applied in the first slot. After l:i1EI,
`multi-slot packet, the channel continues on"
`the hop as dictated by the master clock. For
`example. let us consider four slots: .e,
`.ia+ i.
`12+2 and E-1-3. Ordinarily, these would be as-
`sociated with hop frequencies fig, jg, ,. f;,,2
`andfhj. However, a three-slot packet that
`starts in slot £2 usesfk For the entire packet.
`The next packet begins in slot é+3 and uses
`Jg+3'
`
`Physical link definition
`Two types of link have been def] ned for sup-
`porting multimedia applications that mix
`voice and data:
`
`Table 1
`Radio parameters.
`
`?2 bits
`
`54 bits
`
`D-27115 hits
`
`- lml
`HCCBS5
`Packet
`C008
`header
`
`Payload
`
`Figure 4
`Fixed packet format.
`
`Figure 5
`Header fields.
`
`3
`
`4
`
`1
`
`1
`
`El
`
`' Synch ronoos connection-oriented (SCO)
`link;
`
`
`
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:25)
`Samsung Ex. 1108A p. 6
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`113
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`
`DM3
`DH3
`
`.
`
`Asymmetric
`(limit/S)
`103.3
`108.8
`1 ? 2 8
`172 .8
`384
`576.0
`4'.FT.8
`721.0
`
`86.4
`36.3
`57.6
`
`Achlovahle data rates (In ltbit/s} on the AOL
`link.
`
`Flgure 6
`S00 and AOL links In a piconet with one
`master and two slaves.
`
`0 asynchronous connectionless (ACL) link.
`SCO links support symmetrical, circuit-
`switched, point-to-point connections typi-
`cally used for voice. These links are defined
`on the channel by reserving two consecutive
`slots (forward and return slots) at fixed in-
`tervals.
`AC]. links support symmetrical or asym-
`metrical,
`packet—switchecl,
`point-to-
`multipoint connections typically used for
`bursty data transmission. Master units use
`a polling scheme to control AC1. connec-
`tions.
`
`A set of packets has been defined for each
`physical link.
`0 For SCO links, three kinds ofsingle-slot
`voice packet have been defined, each of
`which carries voice at a rate of 64 kbitls.
`Voice is sent unprotected, but if the SCO
`interval
`is decreased, a forward—error-
`correction rate of 2,8 or US can be se-
`lected.
`For AC1. links, 1—slot, 3-slot, and 5-slot
`data packets have been defined. Data can
`be sent either unprotected or protected by
`a 2J3 forward—error-correction rate. The
`maximum data rate—?2l kbitls in one
`direction and 57.6 kbitfs in the reversedi—
`rection—is obtained from an unprotect-
`ed, 5-slot packet. Table 2 summarizes the
`data rates that can be obtained from ACL
`links. DMx represents x-slot, EEC-
`encoded data packets; DI-Ix represents in n-
`protected data packets.
`Figure 6 depicts mixed SCO and ACL links
`on a piconet with one master and two slaves.
`Slave 1 supports an ACL link and an SCO
`link with a si:-t—slot SCO interval. Slave 2
`only supports an ACL link. Note: slots may
`be empty when no data is available.
`
`Interference Immunity
`As mentioned above, the Bluetooth radio
`must operate in an open band that is sub-
`
`ject to considerable uncontrolled interfer-
`ence. Thus, the air interface has been opti-
`mized to deal with interference.
`0 Frequency hopping techniques are ap-
`plied with a high hopping rate and short
`packet lengths (1,600 hopsls for single-
`slot packets). If a packet is lost, only a
`small portion of the message is lost.
`0 Packers can be protected by forward error
`control.
`
`I Data packets are protected by an ARQ
`scheme in which lost data packets are an-
`tomatically retransmitted. The recipient
`checks each received packet for errors. if
`errors are detected, it indicates this in the
`header of the return packet. This results
`in a fast ARQ scl1eme——dc-lays are only
`one slot in duration, and only packets that
`have been lost need to be retransmitted.
`Voice is never retransmitted. instead, a ro-
`bust voice-encoding scheme is used. This
`Scheme, which is based on continuous
`variable slope delta (CVSD) modulation,
`follows the audio waveform (Figure 7"} and
`is very resistant to hit errors—errors are
`perceived as background noise, which in-
`tensifies as bit errors increase.
`
`Networking
`Plconets
`Bluetooth units that are within range ofeach
`other can set up aid but connections. In prin-
`ciple, each unit is a peer with the same hard-
`ware capahilities (unlike cellular systems,
`there is no distinction between terminals
`and base stations). Two or more Bluetooth
`units that share a channel form a piconet. To
`regulate traffic on the channel, one of the
`participating units becomes a master of the
`piconet. Any unit can become a master, but
`by definition, the unit that establishes the
`,_. piconet assumes this role. All other partici-
`pants are slaves. Participants may change
`roles ifa slave unit wants to take over the
`master role. Nonetheless, only one master
`may exist in a piconet at any time.
`Every unit in the piconet uses the master
`identity and clock to track the hopping
`channel. Each unit also has its own (native).
`free—running clock. When a connection is
`established, a clock offset is added to syn-
`chronize the slave clock with the master
`clock. The native clock is never adjusted.
`however, and offsets are solely valid for thfi
`duration of the connection.
`Master units control all traffic on a chan-
`nel. They allocate capacity for SCO links by
`reserving slots. For ACL links, they use 3
`
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:26)
`Samsung Ex. iri98i4&e1r.w7*°-3-199“
`
`

`
`polling scheme. A slave is only permitted to
`send in the slave-to~master slot when it has
`
`been addressed by its MAC address in the
`preceding rnaster—to—slave slot. A master-to-
`slave packet implicitly polls the slave; that
`is, an ordinary traffic packet addressed to a
`slave polls the slave automatically. If no in-
`formation to the slave is available, the mas-
`ter can use a POLL packet to poll the slave
`explicitly. POLL packets consist ofan access
`code and header only. This central polling
`scheme eliminates collisions between sieve
`transmissions.
`
`Establishing connection
`W/hen units are not participating in a picn-
`net, they enter standby mode, from which
`state they periodically listen for page mes-
`sages. From the total set of79 (23) hop cat-
`riers, a subset of 32 (16) wake-up carriers
`l1as been defined. The subset, which is cho-
`sen pseudo-randomly. is determined by the
`unit identity. Over the wake-up carriers. a
`wake-up sequence visits each hop carrier
`once: the sequence length is 52 (16) hops.
`Every 2,048 slots (L28 5), standby units
`move their wake—up hop carrier forward one
`hop in the wake-up sequence. The native
`clock ofthe unit determines the phase ofthe
`wake-up sequence. During the listening in-
`terval, which lasts for IS slots or 11.25 ms,
`the unit listens on a single walce—up hop car-
`rierand correlates incomingsignalswith the
`access code derived from its own identity. If
`the cotrelator triggers—that is, if most of
`the received bits match the access code—the
`unit
`activates
`itself
`and
`invokes
`a
`con nection-setup procedure. Otherwise, the
`unit returns to sleep until the next wake-up
`event.
`
`in standby
`Units connecting to a unit
`mode must know the standby unit's identi-
`ty and preferably its native clock
`' to generate the required access code
`(which constitutes the paging message);
`0 to derive the walte—up sequence;
`0 to predict the phase of this sequence.
`Since paging units cannot accurately know
`the native clock ofa recipient. they must re-
`solve the time~frequency uncertainty, They
`do so by transmitting the access code con-
`tinuously—not only in the hop in which
`they expect the recipient to wake up, but
`also in hops before and after. For a period of
`10 ms. paging units transmit the access code
`sequentially on several hop frequencies
`around the expected hop Qarrier. Note: the
`access code is only 72 bits long (72 ms).
`Therefore, many codes can be sent in the
`
`Ericsson Review No. 3. 1998
`
`
`
`11000000101111l0l0Cl0Cl111Cl0C|101D10 . .
`
`.
`
`.
`
`. ..
`
`Flgure T
`Continuous variable slope delta {OVSD} wave-
`form coding.
`
`space of 10 ms. The 10 ms train of access
`codes on different hop carriers is transmit-
`ted repeatedly until the recipient responds
`or a time—out is exceeded.
`Wllen a paging unit and recipient select
`the same wal<e—up carrier. the recipient te-
`ceives the access code and returns an ac-
`
`then
`knowledgement. The paging unit
`sends a packet containing its identity and
`its current clock. After the recipient ac-
`knowledges this packet, each unit uses the
`paging unit's parameters for hop selec-
`tion—thereby establishing a piconet
`in
`which the paging unit acts as the master.
`To establish a connection, the paging unit
`must obtain the identity of units within
`transmission range. Therefore. it executes an
`inquiry procedure: the paging unit trans-
`mits an inquiry access code (which is com-
`mon to all Bluetooth devices) on the inquiry
`wake-up carriers. \X/hen a recipient receives
`the inquiry, it returns .1 packet containing
`its identity and cloclt—tl1e very opposite of;
`the paging procedure. After having gath-
`ered each response, the paging unit can then
`select a specific unit to page (Figure 8).
`
`Scatternet
`
`Users ofa channel must share capacity. Al-
`though channels are 1 MHz wide, as more
`and more users are added, throughput per
`user quickly drops to less than a few tens of
`lcbitfs. Fu rthermore. although the medium
`available bandwidth is 80 MHz in the US
`and Europe (slightly less in Japan, France
`and Spain),
`it cannot be used efficiently
`when every unit must share the same 1 MHZ
`hop channel. Therefore, another solution
`was adopted.
`
`Flgure 8
`connection-establishment procedure and
`maximum time associated with establishing
`a connection.
`
`
`
`Typical
`Max.
`
`5.12 5
`
`15.36 s
`
`0.64 5
`
`"L53 s
`
`0.1-300 minutes
`—
`
`(cid:54)(cid:68)(cid:80)(cid:86)(cid:88)(cid:81)(cid:74)(cid:3)(cid:40)(cid:91)(cid:17)(cid:3)(cid:20)(cid:20)(cid:19)(cid:27)(cid:36)(cid:3)(cid:83)(cid:17)(cid:3)(cid:27)
`Samsung Ex. 1108A p. 8
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`
`piconet need only be shared by users of that
`piconet. Because individual piconets hop
`differently, different piconets can simultaw
`neously use different hop channels. Conse-
`quently, units in one piconet do not share
`their 1 MHz channel with units in another
`piconet. The aggregate throughput
`(the
`total throughput accumulated over all pi-
`conets) increases as more piconets are added.
`Collisions do occur, however, when two pi~
`conets use the same hop channel simultane-
`ously. As the number of piconets increases,
`performance in the frequency-hop system
`degrades gracefully. Simulations of ii scat-
`ternetconsisring oflopiconets ind icate that
`reduction in throughput per piconet is less
`than 10%.1n thescatternet, the radio medi-
`um is shared; in a piconet, the channel and
`information are shared.
`
`Since every piconet uses the same band-
`width, each shares the 80 MHz in an aver-
`age sense. Provided they select different hop
`channels, however, no two piconets must si-
`multaneously share the same 1 MHz chan-
`nel.
`Let us assume there are 100 risers. Ifeath
`
`belonged to the same network, all 100 users
`would have to share the same 1 MHz chan-
`nel. Thus, average throughput per user
`would be 10 kbit/S and aggregate through-
`put would be I Mbitfs. However, if not
`everyone wanted to talk to each other, we
`could Split the piconet
`into independent
`piconets. For example, if the users separat-
`ed themselves into groups of five, then we
`could create 20 independent piconets. With
`only five users sharing the l MI-12. hop chan-
`nel,
`throughput per user
`increases
`to
`200 kbitfs and aggregate throughput in—
`creases to 20 Mbitfs. Obviously, this as-
`sumes ideal conditions, where no two pico-
`nets select the same hop channel at the same
`, time. In reality——because the piconets hop
`independent1y—collisions will occur,
`re-
`ducing effective throughput. Nonetheless.
`the final throughput obtained from multi-
`ple piconets exceeds that of a single piconet-
`The maximum number of units that can
`actively participate on a single piconet is
`eight: one master and seven slaves. The
`MAC address in the packet header, which is
`used to distinguish each unit, is limited to
`three hits. Figure 9 illustrates the SCattel'l‘lE‘E
`approach applied to the scenario shown in
`Figure 1.
`
`Inter-plconet communication
`Different piconets
`adhere
`to different
`freqL1ency—hop sequences and are controlled
`
`Access point-,
`
`
`
`Figure 9
`A scattarnet of four piconets applied to the
`scenarlo described In Figure 1.
`
`Units that share the same area and that
`are within range of one another