WiMAX Bluetooth

8/6/2019 WiMAX Bluetooth

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IEEE 802.16 and 802.15

10/6/2008 2

Outline

• An overview

• An insight into IEEE 802.16 WiMAX

• An introduction to Bluetooth

10/6/2008 3

Background: Wireless Landscape

Satellite

Global Area Network

Fixed Broadband Wireless (e.g.802.16)Cellular Mobile Networks (e.g. GPRS,3G)

Local Area Networks(e.g. 802.11)

Personal AreaNetwork

Increasing Coverage Area

High Cost&

Complex i ty

High-Speed Connectivity

&Hierarchy o f NetworksLow Cost &

Complex i ty

10/6/2008 4

Background: Wireless Technologies

PAN(Personal Area

Network)

LAN(Local Area Network)

MAN(Metropolitan Area Network)

PDAs, Mobile Phones,PDAs, Mobile Phones,cellular accesscellular access

T1 replacement, lastT1 replacement, lastmile accessmile access

Enterprise networksEnterprise networksPeer Peer --toto--Peer Peer

DeviceDevice--toto--DeviceDeviceApplicationsApplications

LongLongMediumMedium--LongLongMediumMediumShortShortRangeRange

10 to 384Kbps10 to 384Kbps11 to 100+ Mbps11 to 100+ Mbps11 to 54 Mbps11 to 54 Mbps< 1Mbps< 1MbpsSpeedSpeed

GSM, GPRS,GSM, GPRS,CDMA, 2.5CDMA, 2.5--3G,3G, 802.16802.16

802.16802.16MMDS, LMDSMMDS, LMDS

802.11802.11HiperLAN2HiperLAN2

Bluetooth, UWBBluetooth, UWBStandardsStandards

WANWANMANMANLANLANPANPAN

WAN(Wide Area Network)

10/6/2008 5

What is WiMAX?

• WiMAX (Worldwide Interoperability for Microwave

Access)

– BWA (Broadband Wireless Access) Solution

– Standard (IEEE 802.16 is the standard) for constructing Wireless

Metropolitan Area Networks (WMANs)

– Can go places where no wired infrastructure can reach

– Backhauling Wi-Fi hotspots & cellular networks

– Offers new and exciting opportunities to established and newly

emerging companies

• Incorporate cable (wired technology) standard

• Comply with European BWA standard

10/6/2008 6

WiMAX Overview

• Complement the existing last

mile wired networks (i.e. xDSL,

cable modem)

• Fast deployment, cost saving

• High speed data, voice and

video services

• Fixed BWA, Mobile BWA



10/6/2008 7

Comparing Technologies

Cisco, Motorola,

Qualcom and

Flarion

Standards coming

Product late ‘06

802.20 in

development

Licensed

<3.5 GHz

Full mobility

3 –8 km

Up to 1.5 Mbps each

802.20Mobile-FI

GSM Wireless

Industry

CW in 6+ cities

Part of GSM

standard

Licensed

Existing wireless

spectrum

Full mobility

Coverage is overlaid

on wireless

infrastructure

384 Kbps –2 Mbps

UMTS3G

Products 2H05In market todayAvailability

802.16, 802.16a and 802.16

REVd standardized, other

under development

802.11a, b and g

standardizedStandardization

BothUnlicensedLicensing

Intel, Fujitsu, Alcatel,

Siemens, BT, AT&T,

Qwest, McCaw

2-11 GHz for 802.16a

11-60 GHz for 802.16

Fixed (Mobile - 16e)

30 –50 km

2 - 5 km (’07)

Share up to 70 Mbps

802.16WiMAX

Industry-wideBackers

2.4 GHz for 802.11b/g

5.2 GHz for 802.11a

Frequency/

Spectrum

PortableMobility

100 meters

30 meters

Range (LOS)

Range (NLOS)

11-54 Mbps sharedBandwidth

802.11WiFi

10/6/2008 8

Potential Services

None (today)

None (today)

No

Yes

No

Limited, QoS

concerns

802.20Mobile-FI

WEPDeveloping WEPWEP &

802.11iSecurity

802.16b in

development

Yes, large scale

Yes

Possible, QoS

concerns

Limited, QoS

concerns

802.16WiMAX

None (today)802.11eQoS

NoYes, small scaleWLAN

YesYesData/Internet

Possible, via

HSDPAYes, in homeVideo

YesLimited, QoS

concernsVoIP

UMTS3G

802.11WiFi

10/6/2008 9

Benefits of WiMAX

● Speed

– Faster than broadband service

● Wireless – Not having to lay cables reduces cost

– Easier to extend to suburban and rural areas

● Broad coverage – Much wider coverage than WiFi hotspots

An Insight into IEEE 802.16

10/6/2008 11

IEEE 802.16 Evolution

• Fixed BWA at 10-66hz

• Line of sight

• Fixed BWA at 2-11hz

• None line of sight

• Revision of 802.16

• Combine previous 802.16 standards

• Mobile BWA based on 802.16-2004 (802.16a)

• Roaming with vehicular speed

10/6/2008 12

IEEE 802.16 Specifications• 802.16a

– use the licensed andlicense-exemptfrequencies from 2 to11Ghz

– Support Mesh-Network• 802.16b

– Increase spectrum to 5and 6GHz – Provide QoS(for real-

time voice and videoservice)

• 802.16c

– Represents a 10 to 66GHz system profile

• 802.16d

– Improvement and fixes for 802.16a

• 802.16e

– Addresses on Mobile

– Enable high-speed signal handoffs necessary for communications with users movingat vehicular speeds



10/6/2008 13

IEEE 802.16 Basics

Same as 802.16d with sub-channelization

Pedestrian mobility

High-speed mobility

OFDMA

OFDM

Up to 75 Mbps at 20MHz

Non line of sight

< 11 GHz

Approved on Dec.7, 2005

802.16e

FixedMobility

Non line of sightChannelConditions

< 11 GHzSpectrum

802.16a: Jan 2003

802.16REVd: Q3’04

Completed

Selectable channel bandwidthsbetween 1.25 and 20 MHz

ChannelBandwidths

OFDM 256 sub-carriers

QPSK, 16QAM, 64QAM

Modulation

Up to 75 Mbps at 20MHzBit Rate

802.16a/REVd

10/6/2008 14

IEEE 802.16 Operation

• WiMAX consists of two parts

– A WiMAX tower, similar in concept to a cell-phone tower - A singleWiMAX tower can provide coverage to a very large area -- as big as3,000 square miles

– A WiMAX Receiver The receiver and antenna could be a small box or PCMCIA card, or they could be built into a laptop the way WiFi accessis today

10/6/2008 15

How WiMax Works

• WiMax can provide 2 forms of wireless services:

- Non-LOS, Wi-Fi sort of service, where a small antenna ona computer connects to the tower. Uses lower frequencyrange (2 to 11 GHz).

- LOS, where a fixed antenna points straight at the WiMaxtower from a rooftop or pole. The LOS connection isstronger and more stable, so it is able to send a lot of datawith fewer errors. Uses higher frequencies, with rangesreaching a possible 66 GHz.

Through stronger LOS antennas, WiMax transmittingstations would send data to WiMax enabled computers or routers set up within 30 (3,600 square miles of coverage)

mile radius.10/6/2008 16

WiMax Spectrum

• Broad Operating Range

• WiMax Forum is focusing on 3 spectrum bands for globaldeployment:

• Unlicensed 5 GHz: Includes bands between 5.25 and 5.85GHz. In the upper 5 GHz band (5.725 – 5.850 GHz) manycountries allow higher power output (4 Watts) that makes itattractive for WiMax applications.

• Licensed 3.5 GHz: Bands between 3.4 and 3.6 GHz havebeen allocated for BWA in majority of countries.

• Licensed 2.5 GHz: The bands between 2.5 and 2.6 GHzhave been allocated in the US, Mexico, Brazil and in someSEA countries. In US this spectrum is licensed for MDS

and ITFS.

10/6/2008 17

Benefits of Licensed andLicense-Exempt Solutions

More worldwide optionsHigher barriers for entrance

Lower CostsBetter NLOS receptionat lower frequencies

Fast RolloutBetter QoS

License-Exempt SolutionLicensed Solution

10/6/2008 18

Technical Similarities and Differences BetweenLicensed and License-Exempt Bands

• Both solutions are based on IEEE 802.16-2004standard, which uses OFDM in the physical(PHY) layer.

• OFDM provides benefits such as increased SNRof subscriber stations and improved resiliency tomulti-path interference.

• For creating bi-directional channels for uplinkand downlink, licensed solutions use FDD whilelicense exempt solutions use TDD.



10/6/2008 19

Time Division Duplexing (TDD)

“Bursty”, asymmetrical data applications,environments with varying traffic patterns,where RF efficiency is more important thancost.

Usage

Cannot transmit and receive at the sametime.

Disadvantages

Enhanced flexibility, easier to pair with smartantenna technologies, asymmetrical.

Advantages

A duplexing technique used in license-exempt solutions, which uses a singlechannel for uplink and downlink.

Description

10/6/2008 20

Time Division Duplexing (TDD)

● In case of TDD both uplink and downlink transmissions share the

same frequency but are separated on time

● A TDD frame has a fixed duration and also consists of one uplink

and one downlink frame

● TDD framing is Adaptive

10/6/2008 21

Frequency Division Duplexing(FDD)

Usage

Disadvantages

Advantages

Description

Environments with predictable traffic patterns,

where equipment costs are more important thanRF efficiency.

Cannot be deployed where spectrum isunpaired, spectrum is usually licensed, higher cost associated with spectrum purchase.

Proven technology for voice, designed for symmetrical traffic, does not require guard time.

A duplexing technique used in licensedsolutions that uses a pair of spectrum channels,one for the uplink and another for the downlink.

10/6/2008 22

Frequency Division Duplexing (FDD)

• In case of FDD both uplink and downlink channels are on separatefrequencies

• The capability of downlink to be transmitted in bursts simultaneouslysupports two different modulation types

– Full Duplex SS's (which can transmit and receive simultaneously

– Half Duplex SS's (which cannot)

10/6/2008 23

Architecture

● P2MP (Point to Multi point)

– Wireless MAN

– BS connected to Public Networks

– BS serves Subscriber Stations (SS)

– Provides SS with first mile access to Public Networks

● Mesh Architecture

– Optional architecture for WiMAX

10/6/2008 24

P2MP Architecture

Line-of-Sight

Backhaul802.16d

802.16

Telco Core

Network or

Private (Fiber)

Network

Non Line-of-Sight

Point to Multi-Point

BaseStation

INTERNET

BACKBONE



10/6/2008 25

Mesh Architecture

10/6/2008 26

Reference Model

• Supports multiple services (e.g. IP, voice over IP, video)simultaneously, with different QoS priorities

• Covers MAC layer and PHY layer

10/6/2008 27

MAC Layer

• Wireless MAN: Point-to-Multipoint andoptional mesh topology

• Connection-oriented

– Connection ID (CID)

● MAC layer is further subdivided intothree layers – Convergence sub-layer (CS)

– Common part sub-layer (CPS)

– Privacy sub-layer

10/6/2008 28

MAC Addressing

● SS has 48-bit 802.3 MAC address

● BS has 48-bit base station ID – Not a MAC address

● Connection ID (CID) – 16 bit – Used in MAC PDU – Connection Oriented Service

10/6/2008 29

MAC PDU

• Each MAC packet consists of the three components,

– A MAC heade r, which contains frame control information.

– A variable length frame bod y, which contains information specific to theframe typ e.

– A frame check sequence (FCS), which contains an IEEE 32-bit cyclic

redundancy code (CRC).

CRC(optional)MAC PDU payload (optional)

Generic MACHeader

(6 bytes)

LENmsb(3)

HT

CID msb (8)LEN lsb (8)

Generic MAC Header Format(Header Type (HT) = 0)

BW Req. Header Format(Header Type (HT) =1)

msb lsb

EC

Type (6 bits)rsv

CI

EKS(2)

rsv

HCS (8)CID lsb (8)

BW Req.msb (8)

HT

CID msb (8)BWS Req. lsb (8)

EC

Type (6 bits)

HCS (8)CIDlsb (8)

10/6/2008 30

MAC PDU Types

● Data MAC PDUs

– HT = 0

– Payloads are MAC SDUs/segments, i.e., data from upper layer (CSPDUs)

– Transmitted on data connections

● Management MAC PDUs

– HT = 0

– Payloads are MAC management messages or IP packets encapsulatedin MAC CS PDUs

– Transmitted on management connections

● BW Req. MAC PDUs

– HT = 1; and no payload, i.e., just a Header



10/6/2008 31

MAC PDU Transmission

● MAC PDU’s are transmitted on PHY bursts

●

The PHY burst can contain multiple FEC blocks

● Concatenation – Multiple MAC PDU's can be concatenated into a single transmission in

either uplink or downlink direction

● Fragmentation – Each MAC SDU can be divided into one or more MAC PDU's

● Packing – Packs multiple MAC SDU's into a single MAC PDU

10/6/2008 32

MAC CS Sub-layer

● Interoperability requires convergencesub-layer to be service specific

● Separate CS layers for upper layer (ATM & packet) protocols

● CS Layer:

– Receives data from higher layers

– Classifies data as ATM cell or packet

– Forwards frames to CPS layer

10/6/2008 33

MAC CPS Sub-layer

● Performs typical MAC functions such as

addressing

– Each SS assigned 48-bit MAC address

– Connection Identifiers used as primary

address after initialization

● MAC policy determined by direction of

transmission

– Uplink is DAMA-TDM

– Downlink is TDM

● Data encapsulated in a common format

facilitating interoperability

– Fragment or pack frames as needed

– Changes transparent to receiver 10/6/2008 34

MAC Privacy Sub-layer

● Provides secure communication

– Data encrypted with cipher clockchaining mode of DES

● Prevents theft of service

– SSs authenticated by BS using keymanagement protocol

10/6/2008 35

How It Works

http://www.networkworld.com/news/tech/2001/0903tech.html

10/6/2008 36

802.16 Network Entry

• Scanning

– Scan for BS downlink channel

– Synchronize with BS

– Specifies channel parameters

• Ranging – Set PHY parameters correctly

– Establish the primary management channel (for negotiation, authentication,

and key management)

• Registrat ion

– Result in establishment of secondary management connection (for transfer

of standard based management messages such as DHCP, TFTP )

• Establishment of transport connection



10/6/2008 37

IEEE 802.16 Features

• Scalability

• QoS• Range

• Coverage

• WiMAX vs. Wi-Fi

10/6/2008 38

IEEE 802.11 vs. IEEE 802.16 (1/4)

• Scalability

– 802.11• Channel bandwidth for 20MHz is fixed

• MAC designed to support 10’s of users

– 802.16• Channel b/w is flexible from 1.5 MHz to 20 MHz.

• Frequency re-use.

• Channel bandwidths can be chosen by operator (e.g. for sectorization)

• MAC designed to support thousands of users.

10/6/2008 39

IEEE 802.11 vs. IEEE 802.16 (2/4)

• Quality Of Service (QoS)

– 802.11• No QoS support today (802.11e working to standardize )

• Contention-based MAC (CSMA/CA) => no guaranteed QoS

– 802.16• QoS designed in for voice/video

• Grant-request MAC

• Supports differentiated service levels.

– e.g. T1 for business customers; best effort for residential.

• Centrally-enforced QoS

10/6/2008 40

IEEE 802.11 vs. IEEE 802.16 (3/4)

• Range – 802.11

• Optimized for users within a 100 meter radius

• Add access points or high gain antenna for greater coverage

• Designed to handle indoor multi-path delay spread of 0.8μseconds

– 802.16• Optimized for typical cell size of 7-10km

• Up to 50 Km range

• No “hidden node” problem

• Designed to tolerate greater multi-path delay spread (signal

reflections) up to 10.0μ seconds

10/6/2008 41

IEEE 802.11 vs. IEEE 802.16 (4/4)

• Coverage – 802.11

• Optimized for indoor performance

• No mesh topology support within ratified standards

– 802.16• Optimized for outdoor NLOS performance (trees, buildings,

users spread out over distance)

• Standard supports mesh network topology

• Standard supports advanced antenna techniques

10/6/2008 42

Introduction to Bluetooth



10/6/2008 43

Bluetooth

• named after a Danish Viking and King, Harald Blåtand

• it is a cable-replacement technology: new technology

using short-range radio links, intended to replace thecable(s) connecting portable and/or fixed electronic devices

• conceived initially by Ericsson in 1994, set to commerciallycome out in bulk around 2002

• a standard for a small , cheap radio chip to be pluggedinto computers, printers, mobile phones, etc

• The Bluetooth Special Interest Group (SIG) was foundedby Ericsson,IBM,Intel,Nokia and Toshiba in February 1998,to develop an open specification for short-range wirelessconnectivity

10/6/2008 44

Bluetooth

• Bluetooth radio modules operate in the unlicensedISM band centered at at 2.45GHz. RF

channels:2402+k MHZ, k=0..78.• Bluetooth devices within 10m of each other canshare up to 720kbps of capacity

• Projected cost for a Bluetooth chip is ~$5. Plus itslow power consumption, means you could literallyplace one anywhere.

• Can operate on both circuit and packet switchingmodes, providing both synchronous andasynchronous data services

• It is intended to support an open-ended list of applications, including data, audio, graphics andeven video.

10/6/2008 45

Bluetooth

• Bluetooth must be able to:• Recognize any other Bluetooth device in radio range• Permit easy connection of these devices• Be aware of the device types • Support service discovery• Support connectivity aware applications

• Examples of Bluetooth uses:• Briefcase email : access email while the PC is still in

the briefcase; when PC receives an email, you arenotified thru the mobile phone. Use the mobile phoneto browse the email.

• Cordless desktop : connect your desktop/laptop

cordlessly to printers, scanner, keyboard, mouse, etc.10/6/2008 46

IEEE 802.15• In 1999, IEEE established a working group for wireless

personal area networks (WPAN) – Contains multiple subgroups

• IEEE 802.15.1 – Standardizes the lower layers of the Bluetooth (together with the

Bluetooth consortium)

– Bluetooth also specifies higher layers

• IEEE 802.15.2 – Focuses on the coexistence of WPAN and WLAN

– Proposes the adaptive frequency hopping (used since version 1.2) thatrequires a WPAN device check for the occupied channels and excludethem from their hopping list

• IEEE 802.15.3 – For high-rate at low-power low cost

• IEEE 802.15.4

– Low-rate low-power consumption WPAN enabling multi-year battery life – Zigbee consortium tries to standardize the higher layers of 802.15.4

10/6/2008 47

Bluetooth is a PAN Technology

• Offers fast and reliable transmission for both voice and data

– Can support either one asynchronous data

channel with up to three simultaneoussynchronous speech channels or one channelthat transfers asynchronous data andsynchronous speech simultaneously

– Support both packet-switching and circuit-switching

10/6/2008 48

Personal Area Network (PAN)



10/6/2008 49

Bluetooth is a standard that will …

• Eliminate wires and cables between both

stationary and mobile devices• Facilitate both data and voice

communications

• Offer the possibility of ad hoc networksand deliver synchronicity betweenpersonal devices

10/6/2008 50

Characteristics of BluetoothTechnology

2M is expected for Bluetooth 2

7 9 f r e q u e n c i e s , e a c h

c h a n n e l i s u s e d

f o r 6 2 5 m i c r o s e c o n d s

10/6/2008 51

Bluetooth Topology• Bluetooth-enabled devices can

automatically locate each other

• Topology is established on atemporary and random basis

• Up to eight Bluetooth devices maybe networked together in amaster-slave relationship to forma piconet – One is master, which controls and setup

the network

– All devices operate on the same channeland follow the same frequency hoppingsequence

– The slave of one piconet can be themaster of another piconet

• Two or more piconet interconnectedto form a scatternet Only one master for each picon A device can’t be masters for two

piconets

10/6/2008 52

A Typical Bluetooth Network

10/6/2008 53

Piconet• Master sends its globally unique 48-bit id and clock

– Hopping pattern is determined by the 48-bit device ID

– Phase is determined by the master’s clock

• Why at most 7 slaves? – Active member address is 3-bit

• Parked and standby nodes – Parked devices can not actively participate in the piconet but are

known to the network and can be reactivated within somemilliseconds

– 8-bit for parked nodes

– No id for standby nodes

– Standby nodes do not participate in the piconet

10/6/2008 54

ScatterNet• FH-CDMA to separate piconets within a scatternet

• More piconets within a scatternet degrades performance – Possible collision because hopping patterns are not coordinated

• A device participating in more than one piconet – At any instant of time, a device can participate only in one piconet

– If the device participates as a slave, it just synchronize with themaster’s hop sequence

– The master of a piconet can join another piconet as a slave; in thiscase, all communication within in the former piconet will besuspended

– When leaving a piconet, a slave notifies the master about itsabsence for certain amount of time

• Communication between different piconets takes place bydevices jumping back and forth between these nets



10/6/2008 55

Frequency Selection• FH is used for interference mitigation and media access;

TDD is used for separation of the transmission directions – In 3-slot or 5-slot packets, why frequency does not change? Why

some frequencies are skipped?

M S M S M S M

f k f k+1 f k+2 f k+3 f k+4 f k+5 f k+6

M (3-slot packet) S M S M

f k f k+3 f k+4 f k+5 f k+6

M S (5-slot packet) M

f k f k+1 f k+6

10/6/2008 56

Physical Links

• Synchronous Connection Oriented (SCO) : allocates a fixedbw between a point-to-point connection involving the master andone slave.

– The master reserves slots periodically.

– It primarily supports time-bounded information like voice.

– SCO packets do not include a CRC and are never retransmitted.

– The master can support up to 3 simultaneous SCO links

• Asynchronous connectionless (ACL) : a point-to-multipointlink between the master and all slaves in the piconet.

– Packet-switch style of connection

– No bw reservation possible

– Delivery may be guaranteed thru error detection and retransmission

– Only single ACL link can exist

10/6/2008 57

Physical Links

• Synchronous connection-oriented link (SCO)

– Reserve two consecutive slots at fixed intervals

• Asynchronous connectionless Link (ACL)

– Polling scheme – master polls each slave

• Error recovery

– ACK a packet in the slot following the packet

– Negative ACK or timeout signals aretransmission

10/6/2008 58

Benefits

• Cable Replacement – Replace the cables for peripheral devices, USB 1.1 and 2.0, printers,

etc

• Ease of file sharing – Panel discussion, conference, etc.

• Wireless synchronization – Synchronize personal information contained in the address books

and date books between different devices such as PDAs, cellphones, etc.

• Bridging of networks – Cell phone connects to the network through dial-up connection while

connecting to a laptop with Bluetooth.

Documents

WiMAX Bluetooth