1. IEEE and

2. Outline An overview An insight into IEEE 802.16 WiMAX
An introduction to Bluetooth
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3. Background: Wireless Landscape
High-Speed Connectivity
&
Hierarchy of Networks
Low Cost &
Complexity
Personal Area
Network
Local Area Networks
(e.g )
Fixed Broadband Wireless (e.g )
Cellular Mobile Networks (e.g. GPRS,3G)
Satellite
Global Area Network
High Cost &
Complexity
Increasing Coverage Area
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4. Background: Wireless Technologies
WAN
(Wide Area Network)
MAN
(Metropolitan Area Network)
LAN
(Local Area Network)
PAN
(Personal Area Network)
PAN
LAN
MAN
WAN
Standards
Bluetooth, UWB
802.11
HiperLAN2
802.16
MMDS, LMDS
GSM, GPRS,
CDMA, 2.5-3G,
Speed
< 1Mbps
11 to 54 Mbps
11 to 100+ Mbps
10 to 384Kbps
Range
Short
Medium
Medium-Long
Long
Applications
Peer-to-Peer
Device-to-Device
Enterprise networks
T1 replacement, last mile access
PDAs, Mobile Phones, cellular access
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5. What is WiMAX? WiMAX (Worldwide Interoperability for Microwave Access)
BWA (Broadband Wireless Access) Solution
Standard (IEEE 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
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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
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7. Comparing Technologies
WiFi
WiMAX
Mobile-FI
UMTS 3G
Bandwidth
11-54 Mbps shared
Share up to 70 Mbps
Up to 1.5 Mbps each
384 Kbps – 2 Mbps
Range (LOS) Range (NLOS)
100 meters
30 meters
30 – 50 km
2 - 5 km (’07)
3 – 8 km
Coverage is overlaid on wireless infrastructure
Mobility
Portable
Fixed (Mobile - 16e)
Full mobility
Frequency/ Spectrum
2.4 GHz for b/g
5.2 GHz for a
2-11 GHz for a
11-60 GHz for
<3.5 GHz
Existing wireless spectrum
Licensing
Unlicensed
Both
Licensed
Standardization
802.11a, b and g standardized
802.16, a and REVd standardized, other under development
in development
Part of GSM standard
Availability
In market today
Products 2H05
Standards coming Product late ‘06
CW in 6+ cities
Backers
Industry-wide
Intel, Fujitsu, Alcatel, Siemens, BT, AT&T, Qwest, McCaw
Cisco, Motorola, Qualcom and Flarion
GSM Wireless Industry
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8. Potential Services 802.11 WiFi 802.16 WiMAX 802.20 Mobile-FI UMTS 3G
VoIP
Limited, QoS concerns
Yes
Video
Yes, in home
Possible, QoS concerns No
Possible, via HSDPA
Data/Internet
WLAN
Yes, small scale
Yes, large scale
Security
WEP & i
Developing WEP
None (today)
WEP
QoS
802.11e
802.16b in development
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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
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10. An Insight into IEEE

11. IEEE 802.16 Evolution Fixed BWA at 10-66hz Line of sight
None line of sight
Revision of
Combine previous standards
Mobile BWA based on (802.16a)
Roaming with vehicular speed
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12. IEEE Specifications
802.16a
use the licensed and license-exempt frequencies from 2 to 11Ghz
Support Mesh-Network
802.16b
Increase spectrum to 5 and 6GHz
Provide QoS (for real- time voice and video service)
802.16c
Represents a 10 to 66GHz system profile
802.16d
Improvement and fixes for a
802.16e
Addresses on Mobile
Enable high-speed signal handoffs necessary for communications with users moving at vehicular speeds
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13. IEEE 802.16 Basics 802.16a/REVd 802.16e Completed 802.16a: Jan 2003
802.16REVd: Q3’04
Approved on Dec.7, 2005
Spectrum
< 11 GHz
Channel Conditions
Non line of sight
Bit Rate
Up to 75 Mbps at 20MHz
Modulation
OFDM 256 sub-carriers
QPSK, 16QAM, 64QAM
OFDMA
OFDM
Mobility
Fixed
Pedestrian mobility
High-speed mobility
Channel Bandwidths
Selectable channel bandwidths between 1.25 and 20 MHz
Same as d with sub-channelization
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14. IEEE 802.16 Operation WiMAX consists of two parts
A WiMAX tower, similar in concept to a cell-phone tower - A single WiMAX tower can provide coverage to a very large area -- as big as 3,000 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 access is today
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15. How WiMax Works WiMax can provide 2 forms of wireless services:
- Non-LOS, Wi-Fi sort of service, where a small antenna on a computer connects to the tower. Uses lower frequency range (2 to 11 GHz).
- LOS, where a fixed antenna points straight at the WiMax tower from a rooftop or pole. The LOS connection is stronger and more stable, so it is able to send a lot of data with fewer errors. Uses higher frequencies, with ranges reaching a possible 66 GHz.
Through stronger LOS antennas, WiMax transmitting stations would send data to WiMax enabled computers or routers set up within 30 (3,600 square miles of coverage) mile radius.
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16. WiMax Spectrum Broad Operating Range
WiMax Forum is focusing on 3 spectrum bands for global deployment:
Unlicensed 5 GHz: Includes bands between 5.25 and 5.85 GHz. In the upper 5 GHz band (5.725 – GHz) many countries allow higher power output (4 Watts) that makes it attractive for WiMax applications.
Licensed 3.5 GHz: Bands between 3.4 and 3.6 GHz have been allocated for BWA in majority of countries.
Licensed 2.5 GHz: The bands between 2.5 and 2.6 GHz have been allocated in the US, Mexico, Brazil and in some SEA countries. In US this spectrum is licensed for MDS and ITFS.
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17. Benefits of Licensed and License-Exempt Solutions
Licensed Solution
License-Exempt Solution
Better QoS
Fast Rollout
Better NLOS reception at lower frequencies
Lower Costs
Higher barriers for entrance
More worldwide options
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18. Technical Similarities and Differences Between Licensed and License-Exempt Bands
Both solutions are based on IEEE standard, which uses OFDM in the physical (PHY) layer.
OFDM provides benefits such as increased SNR of subscriber stations and improved resiliency to multi-path interference.
For creating bi-directional channels for uplink and downlink, licensed solutions use FDD while license exempt solutions use TDD.
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19. Time Division Duplexing (TDD)
Description
A duplexing technique used in license-exempt solutions, which uses a single channel for uplink and downlink.
Advantages
Enhanced flexibility, easier to pair with smart antenna technologies, asymmetrical.
Disadvantages
Cannot transmit and receive at the same time.
Usage
“Bursty”, asymmetrical data applications, environments with varying traffic patterns, where RF efficiency is more important than cost.
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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
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21. Frequency Division Duplexing (FDD)
Description
A duplexing technique used in licensed solutions that uses a pair of spectrum channels, one for the uplink and another for the downlink.
Advantages
Proven technology for voice, designed for symmetrical traffic, does not require guard time.
Disadvantages
Cannot be deployed where spectrum is unpaired, spectrum is usually licensed, higher cost associated with spectrum purchase.
Usage
Environments with predictable traffic patterns, where equipment costs are more important than RF efficiency.
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22. Frequency Division Duplexing (FDD)
In case of FDD both uplink and downlink channels are on separate frequencies
The capability of downlink to be transmitted in bursts simultaneously supports two different modulation types
Full Duplex SS's (which can transmit and receive simultaneously
Half Duplex SS's (which cannot)
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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
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24. Line-of-Sight Backhaul Telco Core Network or Private (Fiber) Network
P2MP Architecture
Base
Station
Non Line-of-Sight
Point to Multi-Point
Line-of-Sight Backhaul
802.16d
802.16
Telco Core Network or Private (Fiber) Network
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INTERNET
BACKBONE

25. Mesh Architecture
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26. Reference Model
Supports multiple services (e.g. IP, voice over IP, video) simultaneously, with different QoS priorities
Covers MAC layer and PHY layer
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27. MAC Layer Wireless MAN: Point-to-Multipoint and optional mesh topology
Connection-oriented
Connection ID (CID)
MAC layer is further subdivided into three layers
Convergence sub-layer (CS)
Common part sub-layer (CPS)
Privacy sub-layer
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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
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29. MAC PDU Each MAC packet consists of the three components,
A MAC header, which contains frame control information.
A variable length frame body, which contains information specific to the frame type.
A frame check sequence (FCS), which contains an IEEE 32-bit cyclic redundancy code (CRC).
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30. MAC PDU Types Data MAC PDUs Management MAC PDUs BW Req. MAC PDUs
HT = 0
Payloads are MAC SDUs/segments, i.e., data from upper layer (CS PDUs)
Transmitted on data connections
Management MAC PDUs
Payloads are MAC management messages or IP packets encapsulated in MAC CS PDUs
Transmitted on management connections
BW Req. MAC PDUs
HT = 1; and no payload, i.e., just a Header
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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
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32. MAC CS Sub-layer
Interoperability requires convergence sub-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
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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
DAMA: Demand Assigned Multiple Access
TDM: Time-Division Multiplexing
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34. MAC Privacy Sub-layer Provides secure communication
Data encrypted with cipher clock chaining mode of DES
Prevents theft of service
SSs authenticated by BS using key management protocol
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35. How It Works
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36. 802.16 Network Entry Scanning Ranging Registration
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)
Registration
Result in establishment of secondary management connection (for transfer of standard based management messages such as DHCP, TFTP )
Establishment of transport connection
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37. IEEE 802.16 Features Scalability QoS Range Coverage WiMAX vs. Wi-Fi
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38. IEEE 802.11 vs. IEEE 802.16 (1/4) Scalability 802.11 802.16
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.
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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
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40. IEEE vs. IEEE (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 0.8μ seconds
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
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41. IEEE 802.11 vs. IEEE 802.16 (4/4) Coverage 802.11 802.16
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
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42. Introduction to Bluetooth
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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 the cable(s) connecting portable and/or fixed electronic devices
conceived initially by Ericsson in 1994, set to commercially come out in bulk around 2002
a standard for a small , cheap radio chip to be plugged into computers, printers, mobile phones, etc
The Bluetooth Special Interest Group (SIG) was founded by Ericsson,IBM,Intel,Nokia and Toshiba in February 1998, to develop an open specification for short-range wireless connectivity
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44. Bluetooth
Bluetooth radio modules operate in the unlicensed ISM band centered at at 2.45GHz. RF channels:2402+k MHZ, k=0..78.
Bluetooth devices within 10m of each other can share up to 720kbps of capacity
Projected cost for a Bluetooth chip is ~$5. Plus its low power consumption, means you could literally place one anywhere.
Can operate on both circuit and packet switching modes, providing both synchronous and asynchronous data services
It is intended to support an open-ended list of applications, including data, audio, graphics and even video.
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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 access while the PC is still in the briefcase; when PC receives an , you are notified thru the mobile phone. Use the mobile phone to browse the .
Cordless desktop: connect your desktop/laptop cordlessly to printers, scanner, keyboard, mouse, etc.
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46. IEEE
In 1999, IEEE established a working group for wireless personal area networks (WPAN)
Contains multiple subgroups
IEEE
Standardizes the lower layers of the Bluetooth (together with the Bluetooth consortium)
Bluetooth also specifies higher layers
IEEE
Focuses on the coexistence of WPAN and WLAN
Proposes the adaptive frequency hopping (used since version 1.2) that requires a WPAN device check for the occupied channels and exclude them from their hopping list
IEEE
For high-rate at low-power low cost
IEEE
Low-rate low-power consumption WPAN enabling multi-year battery life
Zigbee consortium tries to standardize the higher layers of
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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 simultaneous synchronous speech channels or one channel that transfers asynchronous data and synchronous speech simultaneously
Support both packet-switching and circuit-switching
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48. Personal Area Network (PAN)
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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 networks and deliver synchronicity between personal devices
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50. Characteristics of Bluetooth Technology
79 frequencies, each channel is used
for 625 microseconds
2M is expected for Bluetooth 2
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51. Bluetooth Topology
Bluetooth-enabled devices can automatically locate each other
Topology is established on a temporary and random basis
Up to eight Bluetooth devices may be networked together in a master-slave relationship to form a piconet
One is master, which controls and setup the network
All devices operate on the same channel and follow the same frequency hopping sequence
The slave of one piconet can be the master of another piconet
Two or more piconet interconnected to form a scatternet
Only one master for each piconet
A device can’t be masters for two
piconets
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52. A Typical Bluetooth Network
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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 some milliseconds
8-bit for parked nodes
No id for standby nodes
Standby nodes do not participate in the piconet
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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 the master’s hop sequence
The master of a piconet can join another piconet as a slave; in this case, all communication within in the former piconet will be suspended
When leaving a piconet, a slave notifies the master about its absence for certain amount of time
Communication between different piconets takes place by devices jumping back and forth between these nets
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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? fk
fk+1
fk+2
fk+3
fk+4
fk+5
fk+6 M S M S M S M fk
fk+3
fk+4
fk+5
fk+6
M (3-slot packet) S M S M fk
fk+1
fk+6 M
S (5-slot packet) M
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56. Physical Links
Synchronous Connection Oriented (SCO) : allocates a fixed bw between a point-to-point connection involving the master and one 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-multipoint link 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
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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 a retransmission
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58. Benefits Cable Replacement Ease of file sharing
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, cell phones, etc.
Bridging of networks
Cell phone connects to the network through dial-up connection while connecting to a laptop with Bluetooth.
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