A Technical Overview of the WirelessMAN Air Interface for Broadband Wireless Access

1. IEEE 802.16 WirelessMAN A Technical Overview of the WirelessMAN Air Interface for Broadband Wireless Access Carl Eklund Roger B. Marks Kenneth L. Stanwood Stanley Wang 資訊工程學系碩士在職專班 學號 : 492515019 姓名 : 何俊慶

2. Agenda • Why IEEE 802.16 wirelessMAN ? • IEEE 802.16 Standard • 802.16 • 802.16a • 802.16b • IEEE 802.16 theory • Physical Layer • MAC Layer • BS SS initial • Conclusion • References

3. What are WMANs? • WMAN: Wireless Metropolitan Area Network. • They are meant to provide wireless access for large residential areas. • They are designed to provide Broadband Wireless Access (BWA) services. • BWA offers integrated high-speed links supporting data, voice and video communication.

4. Applications • It comprises a “Last Mile” solution. It is a suitable cost-effective solution to replace copper and fiber last mile connections. • Buildings equipped with subscriber and base stations, SS & BS • Users connect to SS via conventional network technologies (e.g. 802.3, 802.11) • BSs connected directly to backbone • Lowers barriers to entry for new ISPs increasing competition

5. “Last Mile” solution

6. LAN PAN MAN WAN Wireless LAN Technology WWAN WPAN WLAN WMAN IEEE-802.16 2.5G,GSM/TDMA/ CDMA 3G,GPRS/WCDMA Personal Area 802.15/Bluetooth Wireless LAN 802.11x/HiperLAN Wireless MAN IEEE-802.16

7. What technologies can we choose from? • sample wireless applications (source: Cisco 2002)

8. Wireless Technologies

9. WMAN Standards

10. General Overview • Standard for wireless metropolitan area networks (WirelessMAN™) • Supports a variety of services such as IP, voice over IP, and streaming video • Protocol independent supporting ATM & packet based protocols

11. Application Presentation ISO OSI 7-layer model Session IEEE 802 standards Transport Network Logical Link Control Data Link Medium Access (MAC) Physical Physical (PHY) Standardization of Wireless Networks • Wireless networks are standardized by IEEE. • Under 802 LAN MAN standards committee.

12. IEEE 802.16 Standard • P802.16 — Air interface for fixed BWA systems at 10-66 GHz • Common MAC definition • Point-to-multipoint (PMP) operation • 2 to 134 Mbps • Bandwidth on Demand system • Requires directional line-of-sight (LOS) propagation

13. IEEE 802.16 Standard • P802.16a — 2-11 GHz licensed bands • Point-to-multipoint BWA system • 3 physical layer specs: Single Carrier, 256-point OFDM, 2048-point multi-user OFDMA • the standard tackles the Non-Line-of-Sight applications • P802.16b — License-Exempt Bands, with a focus on 5-6 GHz • Wireless High-Speed Unlicensed Metropolitan Area Networks (WirelessHUMAN) • Primary focus is 5-6 GHz (UNII band)

14. IEEE 802.16 Theory

15. 802.16 protocol layer

16. 802.16 Physical Layer • Data rates determined by exact modulation and encoding schemes • TDMA and OFDMA

17. Bit Rate Shifting in 802.16 Bit rate shifting is achieved using adaptive modulation. When you are near to the BS, you are offered high speed, when you’re far, reliability decreases, hence you’re offered lower speed.

18. 802.16 MAC • WirelessMAN operates at MAC sub-layer of Data Link Layer • MAC layer is further subdivided into three layers • Convergence sub-layer (CS) • Common part sub-layer (CPS) • Privacy sub-layer

19. IEEE 802.16 MAC layer function • Transmission scheduling : • Controls uplink and downlink transmissions so that different QoS can be provided to each user • Link initialization • Scans for a channel, synchronizes the SS with the BS, performs registration, and various security issues. • Support for integrated voice/data connections • Provide various levels of bandwidth allocation

20. 802.16 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

21. 802.16 MAC: CPS 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 TDMA • Downlink is TDM

22. 802.16 MAC: CS Layer • Interoperability requires convergence sub-layer to be service specific • Separate CS layers for ATM & packet protocols • CS Layer: • Receives data from higher layers • Classifies data as ATM cell or packet • Forwards frames to CPS layer

23. 802.16 MAC Layer FDD map relevance

24. 802.16 MAC Layer TDD map relevance

25. Physical Layer Downlink subframe structure

26. Physical Layer Upnlink subframe structure

27. BS SS initial Transition to a more robust burst profile

28. BS SS initial Transition to a less robust burst profile

29. 802.16 MAC Layer Generic MAC header format

30. 802.16 MAC Layer

31. 802.16 MAC Layer Bandwidth Request header format

32. 802.16 MAC Layer

33. Conclusion

34. WMAN Advantage • 支援可變長度資料封包傳輸 • 提供品質保證 QoS,包含頻寬需求與延遲控制、封包分級、動態連結建立 • 提供安全傳輸服務 • 提供數種傳輸速度 • 提供封包分割重整與TCP/IP相連時提供通透性連接,可直接到任何網際網路 • 建制容易,升級更新容易,成本低

35. References

36. REFERENCES [1] IEEE 802.16-2001,”IEEE Standard for Local Metropolitan Area Networks - Air Interface for Fixed Brodband Wireless Access System.”Apr.8,2002 [2] IEEE P802.16a/D3-2001:”Draft Amendment to IEEE Standard for Local and Metropolitan Area Networks – Air Interface for Fixed Wireless Access Systems – Medium Access Control Modifications and Additional Physical Layers Specifications for 2-11 GHz”Mar.25,2002 [3] IEEE 802.16.2-2001,”IEEE Recommended Practice for Local and Metropolitan Area Networks – Coexistence of Fixed Broadband Wireless Access Systems,”Sep.10,2001