Wireless Mobile Communications: Part 1 Wireless LAN

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Wireless Mobile Communications Part 1
Wireless LAN

• Jae H. Kim, Ph.D.
• Manager/Associate Technical Fellow
• Boeing Phantom Works
• jae.h.kim_at_boeing.com
• [phone]

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Placeholder for Boeing Phantom Woks Overview
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Outline

• PART 1
• Introduction
• Wireless LAN
• IEEE 802.11
• HIPERLAN
• Bluetooth
• HomeRF
• Ultra-Wide Band (UWB)

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Industries are Converging
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Wireless LAN - Market Drivers
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Cellular - Market Drivers

• Cellular systems are deploying packet data
• A foundation for integrating Mobile IP

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Wireless LANIEEE 802.11
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IEEE Standard 802.11
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IEEE 802.11 Layers

• Wireless LAN standard
• IEEE 802.11 for 2.4 GHz ISM band (1, 2 Mbps)
• IEEE 802.11B for 2.4 GHz ISM band (5.5, 11, 20
  Mbps)
• IEEE 802.11A for 5.3/5.8 GHz ISM band (54 Mbps)
• compatible MAC at transmission rates up to 20
  Mbit/s
• coordinate with BRAN (ETSI Broadband Radio Access
  Network)
• PHY Layer
• Direct Sequence Spread Spectrum (DSSS)
• Frequency Hopping Spread Spectrum (FHSS)
• Infrared (IR)
• MAC Layer
• Carrier Sense Multiple Access w/ Collision
  Avoidance (CSMA/CA)
• Automatic Repeat Request (ARQ)
• MAC Management, Power Saving Mode
• Wireless Equivalent Protection (WEP) 128-bit
  encryption

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IEEE 802.11 - Physical layer

• 3 versions 2 RF Radio (typ. 2.4 GHz), 1 IR
• FHSS (Frequency Hopping Spread Spectrum)
• Spreading, despreading, signal strength,
  typically at 1.4 Mbps data rate
• Min. 2.5 frequency hop/s (USA), two-level GFSK
  modulation
• DSSS (Direct Sequence Spread Spectrum)
• DBPSK modulation for 1 Mbit/s (Differential
  Binary Phase Shift Keying), DQPSK for 2 Mbps
  (Differential Quadrature PSK)
• preamble and header of a frame is always
  transmitted with 1 Mbit/s, rest of transmission 1
  or 2 Mbit/s
• Max. radiated power 1 W (USA), 100 mW (EU), min.
  1mW
• Infrared
• 850-950 nm, diffuse light, typ. 10 m range
• Carrier detection, energy detection,
  synchonization

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Spread Spectrum Technology
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IEEE 802.11 Wireless LAN

• Applications nomadic Internet access, portable
  computing, ad hoc networking (multihopping)
• IEEE 802.11 standards define MAC protocol
  operating at unlicensed frequency spectrum bands
  900MHz, 2.4GHz
• Like a bridged LAN (flat MAC address)

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Wireless LAN Configurations
No Base Station
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WaveLAN Features

• IEEE 802.11B compliant
• Direct Sequence Spread Spectrum (DSSS)
• Frequency Band 2.4 GHz
• Throughput 11 Mbps (54 Mbps in IEEE 802.11A)
• Covering Range
• 300 - 800 ft (Indoor with optional range
  extender)
• 800 - 1000 ft (Outdoor with range extender)
• 3-5 mile (Outdoor with omni / directional
  antenna)
• 10 miles (Outdoor with parabolic antenna)
• 40-bit (Silver PCMCIA) and 128-bit (Gold PCMCIA)
  WEP Encryption Capability

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WLAN P-to-P Infrastructure Mode
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WLAN P-to-MP Infrastructure Mode
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Wireless LANHIPERLAN
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HIPERLAN

• ETSI Broadband Radio Access Networks (BRAN)
  specified HIPERLAN 1-4
• HIPERLAN 1
• High-speed wireless LAN
• 2.4 GHz ISM band, data rates up to 23.5 Mbps
• Support both Ad hoc and infrastructure modes
• Provide ranges up to 50m using omni-directional
  antenna
• HIPERLAN 2
• Wireless access to ATM or IP networks
• 5.1-5.3 GHz band, data rates up to 54 Mbps
• Support both Ad hoc and infrastructure modes
• Provide ranges of 50-100m using omni-directional
  antenna

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HIPERLAN (cont.)

• ETSI Broadband Radio Access networks (BRAN)
  specified HIPERLAN 1-4
• HIPERLAN 3 (HIPERACCESS)
• Wireless Local Loop (WLL) to cover last mile to
  customers via a fixed radio link,
  point-to-multipoint with directional antenna
• Alternative to cable modems or xDSL technologies
• 5.1-5.3 GHz with ranges up to 5km, data rates up
  to 54Mbps
• HIPERLAN 4 (HIPERLINK)
• Connect different HIPERLAN or HIPERACCESS nodes
• Provide a fixed point-to-point connection with
  directional antenna
• 17.2-17.3 GHz with ranges to 150m, data rates up
  to 155 Mbps

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HIPERLAN - 2

• Goal is to support all existing and planned
  applications in enterprise, public, and home
• Address the combined WLAN market
• Smooth interworking with 3G
• Affordable technology
• 5 GHz technology, up to 54 Mbit/s
• Generic architecture support Ethernet, IEEE1394,
  ATM, 3G
• Connection-oriented with QoS per connection
• Security - authentication encryption
• Plug-and-play radio network using DFS
• Optimal throughput scheme

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Spectrum Allocation in 5 GHz
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H2GF - The vision
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HIPERLAN2 Global Forum (H2GF)

• Drive the adoption of HIPERLAN-2 as the global
  broadband wireless technology in 5 GHz band,
  providing untethered connectivity for mobile
  devices in corporate, public and home
  environments
• A consortium of 50 companies
• Launched September 1999
• Marketing and education
• Interoperability on system level
• Protect and harmonize spectrum worldwide
• http//www.hiperlan2.com

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HIPERLAN2 Technology

• MAC scheduler at AP
• Centralized control
• Supports uniform traffic load
• Inter Intra system interference mitigation
• Dynamic Frequency Selection (DFS)
• Link Adaptation
• Transmit Power Control (TPC)
• Support of smart (sectored) AP antennas

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HIPERLAN2 - MAC Layer

• Access Point centralized control
• Time Division Duplex - TDMA
• Up and Down link slots allocated dynamically
  based on need
• Data (up/down) transmitted in dedicated slots
• Contention allowed in random access slots

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Wireless LANBluetooth
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Wireless Personal Area Network

• IrDA
• Around since 1994
• Available on every PC and lots of devices
• gt20 million existing IrDA devices
• Camera, PDAs, cellphones, printers, keyboards
• Exploding market fueled by Bluetooth momentum
• Bluetooth wireless technology is a defacto
  standard
• Proliferation of smart devices, convenience of
  cable replacement, and new usage scenarios

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What is Bluetooth ?

• Bluetooth wireless technology is a global,
  RF-based (ISM 2.4GHz band), short-range,
  connectivity technology and solution for
  portable, personal devices
• It is not just a radio
• Create piconets on-the-fly (approximately 1Mbps)
• Piconets may overlap in time and space for high
  aggregate bandwidth
• The Bluetooth spec comprises
• A hardware and software protocol specification
• Usage case scenario profiles and
  interoperability requirements
• To learn more http//www.bluetooth.com

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What Bluetooth does?
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Bluetooth Features

• Cable Replacement

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WLAN Interference with Bluetooth

• Bluetooth hops over nearly all of the 2.4-GHz ISM
  band, making time - frequency collisions with
  802.11B inevitable
• Collision probability varies according to
  factors, e.g.,
• 802.11b data rate and packet length
• Bluetooth activity level and mode
• Impact varies with geometry (e.g., distance
  between nodes) and multiple system parameters
  (e.g., transmit power)
• Bluetooth 802.11B WLAN Interference
• Bluetooth has a greater effect on 802.11B than
  vice versa

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WLAN Throughput with Bluetooth
Source TrueRadio Technology
Low interference to 3 meters, but it is
significant at 10 meters Almost 90 degradation
of 802.11b throughput at 30 meters
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WLAN Throughput with Bluetooth
Source TrueRadio Technology
802.11b max. throughput maintained through 30
meters Only 13.5 degradation over typical
range (withTrueRadio)
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Wireless LANHomeRF
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What is HomeRF ?
To enable the existence of a broad range of
interoperable consumer devices, by establishing
an open industry specification for unlicensed RF
digital communications for PCs and consumer
devices anywhere, in and around the home

• No new wires
• Simple to Install
• Easy to Use
• Low Cost 200 for 2 PCs
• Bandwidth To Support Common Home Applications
• Industry Standards

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Enabling the Vision
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SWAP Network
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HomeRF Origin
DECT Digital Enhanced Cordless
Telecommunications
CSMA/CA Carrier Sense Multiple Access with
Collision Avoidance
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HomeRF - Device Types
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HomeRF - PHY Layer

• Nominal 100 mW transmit power
• Minimum receiver sensitivity of -76 dBm (2FSK)
• Range gt50 m in typical homes/yards
• Sensitivity of -85 dBm typical
• Cost effective filter requirements
• Use MAC to reduce PHY cost
• Makes single-chip integration simpler

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HomeRF - MAC Layer

• MAC provides good support for voice and data
• Leverages existing DECT technology for voice
• Excellent integration with TCP/IP protocols
• easy integration with Ethernet
• Supports broadcast, multicast and fragmenting
• Data security - Basic/Enhanced encryption
• Basic 24-bit Network ID and Frequency Hopping
• Enhanced Basic LFSR algorithm
• Extensive power management for ultra-portable
  devices
• Optimizes existing technology for home use

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Wireless LANUltra-Wide Band (UWB)
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What is Ultra-Wide Band (UWB)?

• UWB signals are typically modulated pulse trains
• Very short pulse duration (lt1 ns)
• Uniform or non-uniform inter-pulse spacing
• Pulse repetition frequency (PRF) can range from
  hundreds of thousands to billions of
  pulses/second
• Modulation techniques include pulse-position
  modulation, binary phase-shift keying and others

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Time Modulated Ultra-Wide Band
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Large Relative Bandwidth

• UWB is a form of extremely wide spread spectrum
  where RF energy is spread over gigahertz of
  spectrum
• Wider than any narrowband system by orders of
  magnitude
• Power seen by a narrowband system is a fraction
  of the total
• UWB signals can be designed to look like
  imperceptible random noise to conventional radios

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Preliminary RO Limits

• Indoor and outdoor communications devices have
  different out-of-band emission limits

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Very Low Power Spectral Density

• FCC limits ensure that UWB emission levels are
  exceedingly small
• At or below spurious emission limits for all
  radios
• At or below unintentional emitter limits
• Lowest limits ever applied by FCC to any system
• Part 15 limits equate to -41.25 dBm/MHz
• For comparison, PSD limits for 2.4 GHz ISM and 5
  GHz U-NII bands are 40 dB higher per MHz
• Total emissions over several gigahertz of
  bandwidth are a small fraction of a milliwatt

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UWB Emission Limit (Indoor)
GPS Band Limit
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UWB Emission Limit (Outdoor)
Limit for Outdoor Hand-held UWB Systems
GPS Band Limit
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Handheld UWB Systems
FCC Spectrum Mask
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FCC UWB Device Classifications

• UWB Report Order (Adopted February 2002)
  authorizes 5 classes of devices Different
  limits for each
• Imaging Systems
• Ground penetrating radars, wall imaging, medical
  imaging
• Thru-wall Imaging Surveillance Systems
• Communication and Measurement Systems
• Indoor Systems
• Outdoor Hand-held Systems
• Vehicular Radar Systems
• collision avoidance, improved airbag activation,
  suspension systems, etc.

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FCC Rules Summary

• Significant protection for sensitive systems
• GPS, Federal aviation systems, etc.
• Lowest Limits Ever by FCC
• Incorporates NTIA recommendations
• Allows UWB technology to coexist with existing
  radio services without causing interference
• The RO rules are designed to ensure that
  existing and planned radio services, particularly
  safety services, are protected.

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Placeholder for UWB Applications
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Co-existance with Legacy Radios ?
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References

• References
• IEEE 802.15-02/133r1 Document, Ultra-Wideband
  Tutorial, edited by Matthew Welborn and Kai
  Siwiak, March 2002.
• UCLA Course note, Ad-hoc Nets MAC Layer Part
  1, CS 218- Fall 2002.
• UCLA Course note, Ad-hoc Nets MAC Layer Part
  2, CS 218- Fall 2002.
• Books
• James D. Solomon, Mobile IP The Internet
  Unplugged, Prentice Hall, 1998.
• Charles E. Perkins, Mobile IP Design Principles
  and Practices, Addison-Wesley, 1998.
• Christian Huitema, Routing in the Internet,
  Prentice Hall, 2000.
• Jochen Schiller, Mobile Communications,
  Addison-Wesley, 2000.
• Charles E. Perkins, Ad-Hoc Networking,
  Addison-Wesley, 2001.
• IETF Working Group URL
• http//www.ietf.org/html.charters/mobileip-charter
  .html