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					        Broadband Wireless Access:
          A Brief Introduction to
         IEEE 802.16 and WiMAX
                Prof. Dave Michelson
                 davem@ece.ubc.ca
               UBC Radio Science Lab

                       26 April 2006                  1




                   Introduction
• The IEEE 802.16/WiMAX standard promises to
  revolutionize wireless delivery of broadband services:
   – an alternative to DSL and cable modems
   – backhaul for access points and base stations
   – long-range connections for private networks
• With standards, development, and certification well-
  advanced, the next major challenge is deployment.
• Now is a good time for wireless professionals to
  become familiar with WiMAX wireless technology

                       26 April 2006                  2




                                                           1
                    Introduction - 2

• What is IEEE 802.16/WiMAX?
  – a wide area alternative to IEEE 802.11/WiFi?
  – a threat to cellular telephony (voice and data)?
  – a method for breaking wireline monopolies?
  – a method for providing backhaul to IEEE
    802.11/WiFi access points?
  – a single standard or a family of standards?
  – a universal solution for broadband wireless access?


                       26 April 2006                 3




                    Introduction - 3

• How is IEEE 802.16/WiMAX different from (or better
  than) other wide area wireless standards?
   – use of OFDM with provision for OFDMA and
     MIMO?
   – support for a wide range of channel bandwidths
     (and, as a result, performance levels)?
   – implementation of differentiated QoS?
   – support for multiple usage models?
   – use of system profiles to manage design options?

                       26 April 2006                 4




                                                          2
                      Objective
 This presentation introduces IEEE 802.16/WiMAX by:
    1. Briefly reviewing its history
    2. Summarizing its key features (and the key
        players)
    3. Reviewing alternative use cases and deployment
        scenarios
    4. Suggesting sources of additional information




                        26 April 2006                    5




1. A Brief History of IEEE 802.16/WiMAX
 • In the mid-1990’s, various groups began to promote
   “last-mile” fixed wireless access solutions.
 • Multiple goals:
    – Provide the capacity and reliability of wireline
      but with the flexibility and ease of deployment
      of wireless
    – Provide a versatile system for corporate or
      institutional backhaul/distribution networks
    – Break the monopolies of incumbent carriers


                        26 April 2006                    6




                                                             3
       A Brief History of IEEE 802.16/WiMAX - 2

Interest soon focused in two approaches.
• LMDS (in Canada, LMCS)
   – operates in mm-wave spectrum under LoS conditions
   – uses conventional QAM modulation with ATM-
     derived upper layers to provide high speed service
• MMDS (and other nearby bands)
   – operates near 2 GHz, usually under LoS conditions
   – may use any of various PHY, MAC, and NET layers


                        26 April 2006                7




      A Brief History of IEEE 802.16 and WiMAX - 3

• High costs, lack of standards and fear of vendor
  lock-in drove off potential LMDS customers.
• In 1999, IEEE 802.16 was formed to address these
  issues by developing open standards for LMDS.
• In 2001, the IEEE 802.16 standard for BWA systems
  operating in the 10-66 GHz range was released!
• Since then, however, interest has shifted to a new
  version of the IEEE 802.16 standard for BWA
  systems operating in the range 2-11 GHz


                        26 April 2006                8




                                                          4
      A Brief History of IEEE 802.16 and WiMAX - 4

• Early BWA concepts were based on early WLAN
  technology and had limited capability.
• In the mid-1990’s, AT&T developed a proprietary
  “last-mile” access solution (Project Angel) that:
   – operated near 2 GHz under either LoS or NLoS
     conditions
   – used OFDM and other advanced concepts
   – delivered high capacity, throughput, and QoS.



                        26 April 2006                  9




      A Brief History of IEEE 802.16 and WiMAX - 5

• By the late 1990’s, many other manufacturers began
  to pursue development of similar products.
• In response, IEEE 802.16 formed a subgroup to
  extend the LMDS standard to the range 2-11 GHz.
• Our work at AT&T led to the propagation and
  channel models adopted by IEEE 802.16.
• IEEE 802.16a was published in 2003.
• IEEE 802.16a/b/c and various updates were
  incorporated into IEEE 802.16-2004.


                        26 April 2006                 10




                                                           5
      A Brief History of IEEE 802.16 and WiMAX - 6

• IEEE 802.16e seeks to provide the additional
  features required to serve mobility users.
• Use of Scalable OFDMA, MIMO, etc. permits 63
  Mbps DL and 28 Mbps UL in a 10 MHz channel.
• Optimized handover ensures latency < 50 ms.
• Flexible key management ensures security.
• South Korea’s WiBro is based upon IEEE 802.16e.
• IEEE 802.16e was ratified in December 2005



                        26 April 2006                11




      A Brief History of IEEE 802.16 and WiMAX - 7

• IEEE 802.16’s approach is being used by many other
  groups including IEEE 802.20, 802.22, 3GPP - LT
• For example, IEEE 802.20 (Mobile Broadband
  Wireless Access) was established on 11 Dec 2002.
• Aim – specify an air interface designed for IP-based
  services operating in bands below 3.5 GHz with peak
  data rates of over 1 Mbit/s.
• A draft IEEE 802.20 specification was balloted and
  approved on 18 Jan 2006.


                        26 April 2006                12




                                                          6
      A Brief History of IEEE 802.16 and WiMAX - 8

• In 2001, the WiMAX Forum was formed to address
  issues beyond standards development, e.g.,
   – marketing and promotion
   – development of system profiles
   – development of certification procedures
   – government lobbying
• In January 2005, the WiMAX Forum selected
  Cetecom Spain as its official certification laboratory.



                        26 April 2006                   13




      A Brief History of IEEE 802.16 and WiMAX - 9

• Many pre-WiMAX and WiMAX networks have
  been trialed and deployed in recent months.
• Pre-WiMAX has several meanings:
   – compliant but not yet certified
   – compliance is possible after a firmware upgrade
   – mostly compliant, but not completely




                        26 April 2006                   14




                                                             7
        A Brief History of IEEE 802.16 and WiMAX - 10

            The WiMAX Value Chain
•   IEEE 802.16 – Standards Working Group
•   WiMAX forum – Industry Advocacy Group
•   Chip Vendors
•   Equipment Vendors           • Certification Labs
•   System Integrators/VARs     • Consultants
                                • Information Providers
•   Carriers/Service Providers
•   End Users

                          26 April 2006                   15




            2. Key Features of WiMAX
• Major goal of IEEE 802.16 (2-11 GHz): provide a
  “universal” solution for broadband wireless access
   – point-to-multipoint, LoS or NLoS
   – ranges of “several” km; urban, suburban, rural
• Problem: Can one size really fit all? Different
  applications have different requirements and
  constraints for spectrum and performance!
• Solution: Allow choice of options within a consistent
  framework. Offer a limited set of standard profiles.


                          26 April 2006                   16




                                                               8
               Key Features of WiMAX - 2

•   Operating Frequency: 2 – 11 GHz***
•   Allocations: Licenced and Unlicenced**
•   Channel Bandwidth: 1.25 – 20 MHz
•   Modulation: Single carrier*, 256 OFDM, 2048 OFDMA
    – BPSK*, QPSK, 16-QAM, 64-QAM, 256-QAM*
• Antenna system support: Diversity, MIMO, SDMA
• Duplexing: FDD, H-FDD, TDD**
• Data Rates: From T1 (1.5 MB/s) to over 70 Mb/s


                       26 April 2006                 17




               Key Features of WiMAX - 3

• WiMAX supports flexible frequency allocation and
  use of system profiles




                       26 April 2006                 18




                                                          9
                Key Features of WiMAX - 4
                                        BPSK, QPSK, 16QAM, 64QAM
 52 carriers,          4 BPSK Pilots
  312.5 kHz
   spacing
                                                       802.11a (18 MHz)
200 carriers,
   90 kHz                               BPSK, QPSK, 16QAM, 64QAM
                       8 BPSK Pilots
  spacing
      .
      .
      .
200 carriers,                           .              802.16 (20 MHz)
  6.7 kHz                               .                          :
                                        .                      10 MHz
  spacing                                                      7.0 MHz
                                                               3.5 MHz
                                                                   :
                                                              1.5 MHz
                        26 April 2006                              19




                Key Features of WiMAX - 5

  • An estimate of the maximum data rate of a WiMAX
    system operating in the 5 GHz band using OFDM
  • System parameters
     – BW = 20 MHz
     – SCM = 64-QAM (1 symbol = 6 bits)
     – No. of data subcarriers = 192
     – Raw data rate = 100 Mb/s
     – After accounting for coding/MAC/TDD overhead,
       the effective data rate is closer to 70 Mb/s

                        26 April 2006                              20




                                                                          10
                 Key Features of WiMAX - 6

The IEEE 802.16 MAC layer supports
• OFDM and OFDMA
• ARQ (Automatic Repeat Request)
• Dynamic Frequency Selection
• Mesh Networking
• Advanced Antenna Systems
• Differentiated Quality of Service
• Enhanced Security


                         26 April 2006                  21




          3. Key Deployment Scenarios
•   Links from carriers to major customers
•   Backhaul for access points and cellular base stations
•   Long-range connections for private networks
•   Supervisory control and data acquisition
•   An alternative to DSL and cable modems
•   An alternative to cellular data services




                         26 April 2006                  22




                                                             11
4. Our Research Interest in Fixed Wireless
• As systems move to higher frequencies, are deployed in
  more challenging environments, or become more
  complex, models must be updated and extended
• Past work has shown that the fixed wireless channel can
  range be extremely harsh.

    Transmitted Signal




                           26 April 2006                23




          Our Research Interest in Fixed Wireless - 2
• Existing channel models do not completely capture the
  dynamics of fixed wireless channels




                           26 April 2006                24




                                                             12
         Our Research Interest in Fixed Wireless - 3

• Fixed wireless channel dynamics is concerned with the
  measurement and simulation of the time-varying
  properties of the channel over the long and short-term.
• Issues include:
   – physical-statistical description of the channel,
   – effect of alternative antenna configurations,
   – development of impairment mitigation strategies,
   – development of more effective radio resource
     management schemes.


                          26 April 2006                25




         Our Research Interest in Fixed Wireless - 3

• Current Sponsors




• Graduate Students:
  – Joy Zhang, Jin Ng, Howard Huang, Anthony Liou



                          26 April 2006                26




                                                            13
5. Probing Further
• IEEE 802.16 - www.ieee802.org/16/




                         26 April 2006    27




                    Probing Further - 2
• WiMAX Forum - www.wimaxforum.org




                         26 April 2006    28




                                               14
                   Probing Further - 3
• WiMAX @ Intel - www.intel.com/go/wimax




                        26 April 2006                        29




                   Probing Further - 4

                                • Other industry portals, e.g.,
                                   – www.wimaxpro.com
                                   – www.wimax-industry.com
                                   – www.wimax.com
                                • Booksellers, e.g.,
                                   – www.chaptersindigo.ca
                                   – www.amazon.ca
                                • WiMAX conferences
                                • Vendors (white papers, etc.)



                        26 April 2006                        30




                                                                  15
                      Summary
• IEEE 802.16/WiMAX broadband wireless access
  supports:
   – channel bandwidths between 1.5 and 20MHz
   – data rates ranging from 1.5Mbps to over 70Mbps
   – the available spectrum and channel widths in
     different countries or licensed to different providers
   – advanced quality-of-service features that ensure
     high performance for data, voice and video
   – system profiles that permit a certain degree of
     customization within the IEEE 802.16 framework

                        26 April 2006                   31




                       Summary - 2

• The IEEE 802.16/WiMAX community has already
  achieved several significant milestones:
   – the IEEE 802.16 standard has been released and
     refined.
   – the WiMAX forum is addressing the needs of
     industry for promotion, certification, etc.
   – vendors have developed silicon and equipment.
• As rollout begins, operators will begin addressing
  issues that arise during deployment and operation.


                        26 April 2006                   32




                                                              16
                     Summary - 3

What will it take for WiMAX to be successful?
• Equipment must perform as advertised:
   – Coverage, reliability, and interoperability
   – Quality of service, throughput and capacity
• Deployment must be straightforward; design rules
  should reduce the need for network tuning
• WiMAX must return value (e.g., performance/cost)
  that is an order of magnitude higher than existing
  technology can.

                       26 April 2006                   33




                      Next….
• Andrew Tsui (Bell Canada) will describe one of the
  largest pre-WiMAX rollouts to date
• Angela Choi (Industry Canada) will summarize
  spectrum allocation and regulatory issues
                    After a break…
• Ben Zarlingo (Agilent Technologies) will describe
  WiMAX test and measurement solutions
• Angela Ikemoto and Michael Fite (Agilent) will
  demonstrate measurement of actual WiMAX signals


                       26 April 2006                   34




                                                            17

				
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Description: Wi-MAX (ie 802.16) technology since 2001 began to develop, now began to appear on the market related products, it is within 30 miles with the most wired LAN provides the same data transfer rate. This technology is considered a large number of broadband connections will be introduced to remote areas or to more decentralized communication covers enterprise and campus area method.