1. 26 April 2006 1 Broadband Wireless Access: A Brief Introduction to IEEE 802.16 and WiMAX Prof. Dave Michelson davem@ece.ubc.ca UBC Radio Science Lab

2. 26 April 2006 2 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

3. 26 April 2006 3 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?

4. 26 April 2006 4 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?

5. 26 April 2006 5 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

6. 26 April 2006 6 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

7. 26 April 2006 7 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

8. 26 April 2006 8 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

9. 26 April 2006 9 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.

10. 26 April 2006 10 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.

11. 26 April 2006 11 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

12. 26 April 2006 12 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.

13. 26 April 2006 13 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.

14. 26 April 2006 14 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

15. 26 April 2006 15 The WiMAX Value Chain IEEE 802.16 – Standards Working Group WiMAX forum – Industry Advocacy Group Chip Vendors Equipment Vendors System Integrators/VARs Carriers/Service Providers End Users Certification Labs Consultants Information Providers A Brief History of IEEE 802.16 and WiMAX - 10

16. 26 April 2006 16 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.

17. 26 April 2006 17 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

18. 26 April 2006 18 Key Features of WiMAX - 3 WiMAX supports flexible frequency allocation and use of system profiles

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

20. 26 April 2006 20 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

21. 26 April 2006 21 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

22. 26 April 2006 22 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

23. 26 April 2006 23 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

24. 26 April 2006 24 Our Research Interest in Fixed Wireless - 2 Existing channel models do not completely capture the dynamics of fixed wireless channels

25. 26 April 2006 25 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. 26 April 2006 26 Our Research Interest in Fixed Wireless - 3 Current Sponsors Graduate Students: –Joy Zhang, Jin Ng, Howard Huang, Anthony Liou

27. 26 April 2006 27 5. Probing Further IEEE 802.16 - www.ieee802.org/16/

28. 26 April 2006 28 Probing Further - 2 WiMAX Forum - www.wimaxforum.org

29. 26 April 2006 29 Probing Further - 3 WiMAX @ Intel - www.intel.com/go/wimax

30. 26 April 2006 30 Probing Further - 4 Other industry portals, e.g., –www.wimaxpro.comwww.wimaxpro.com –www.wimax-industry.comwww.wimax-industry.com –www.wimax.comwww.wimax.com Booksellers, e.g., –www.chaptersindigo.cawww.chaptersindigo.ca –www.amazon.cawww.amazon.ca WiMAX conferences Vendors (white papers, etc.)

31. 26 April 2006 31 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

32. 26 April 2006 32 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.

33. 26 April 2006 33 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.

34. 26 April 2006 34 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