Month 1998 doc IEEE 802 11 00175 5

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Month 1998 doc. : IEEE 802. 11 -00/175 5 -GHz Unified Protocol (5 -UP)

Month 1998 doc. : IEEE 802. 11 -00/175 5 -GHz Unified Protocol (5 -UP) Proposal OFDM Extensions for 802. 11 a Bill Mc. Farland, billm@atheros. com Greg Chesson, greg@atheros. com Carl Temme, ctemme@atheros. com Atheros Communications 01758 E-5 -UP Proposal 1 John Doe, His Company

July 2000 doc. : IEEE 802. 11 -00/175 5 -UP Objectives • Expand Wireless

July 2000 doc. : IEEE 802. 11 -00/175 5 -UP Objectives • Expand Wireless LAN applications space 1. Achieve 100 Mb/s data rate 2. Enable low-cost, low-power, low-speed radios 3. Improve Qo. S and scalability • Provide coexistence and interoperability 1. Between low-end and high-end devices 2. Between legacy and extended systems 3. Compatible extensions to 802. 11 a and Hiper. LAN 2 01758 E-5 -UP Proposal 2 Mc. Farland, Chesson, Atheros Communications

Month 1998 doc. : IEEE 802. 11 -00/175 Overview • • More channels for

Month 1998 doc. : IEEE 802. 11 -00/175 Overview • • More channels for more bandwidth Carrier groups for bandwidth sharing Single-carrier for low power/cost/speed Unified MAC for range of applications 01758 E-5 -UP Proposal 3 John Doe, His Company

July 2000 doc. : IEEE 802. 11 -00/175 Increased Bandwidth • No changes to

July 2000 doc. : IEEE 802. 11 -00/175 Increased Bandwidth • No changes to existing PHY – Identical carriers, OFDM, pilots, modulation, etc. – Use 2 adjacent OFDM channels: 108 Mb/s – Potentially more than 2 channels • Make compatible with single-channel systems – Replicated beacons and protocols – AP/Stations operate in both dual/single modes – Build upon (expected) DFS extensions 01758 E-5 -UP Proposal 4 Mc. Farland, Chesson, Atheros Communications

Month 1998 doc. : IEEE 802. 11 -00/175 5 -UP Mode for 802. 11

Month 1998 doc. : IEEE 802. 11 -00/175 5 -UP Mode for 802. 11 a • • Carrier groups 5 -UP Beacon Single-carrier devices Range Robustness PHY issues: frequency lock, power Topology MAC protocol concepts 01758 E-5 -UP Proposal 5 John Doe, His Company

July 2000 doc. : IEEE 802. 11 -00/175 Carrier Groups 5 -UP Beacon 0

July 2000 doc. : IEEE 802. 11 -00/175 Carrier Groups 5 -UP Beacon 0 1 2 Downlink Uplink 0 1 2 } } 3 } 4 5 } } Carriers • • • } 3 Groups 4 5 IDs Each group includes 1 or more carriers. Group ID assigned by AP. ID’s appear in beacon. Multiple-carrier: OFDM with selected bins nulled. Single-carrier: less complex, low-power/cost/speed. Simultaneous transmission of carrier groups. 01758 E-5 -UP Proposal 6 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 5 -UP Beacon carriers PCF 5

July 2000 doc. : IEEE 802. 11 -00/175 5 -UP Beacon carriers PCF 5 -UP Beacons DCF Period • • Downlink Uplink DCF Period PCF Beacon reserves media time for 5 -UP mode. 5 -UP Beacons control carrier group transfers. Polled data transfers. TDMA also possible. 01758 E-5 -UP Proposal 7 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 One 5 -UP Period 1 carrier

July 2000 doc. : IEEE 802. 11 -00/175 One 5 -UP Period 1 carrier Downlink Uplink 1 carrier 20 carriers 24 carriers 01758 E-5 -UP Proposal 8 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 Proposed Carrier Usage 0 1 2

July 2000 doc. : IEEE 802. 11 -00/175 Proposed Carrier Usage 0 1 2 3 4 5 0 3 1 2 3 4 5 • • 3 4 5 0 1 2 Hop on all carriers. Same sequence for all carriers. Several possible algorithms. Hybrid of hopping and OFDM techniques 01758 E-5 -UP Proposal 9 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 Range • FCC rules limit power

July 2000 doc. : IEEE 802. 11 -00/175 Range • FCC rules limit power spectral density. • All devices scale power with the number of carriers. • Single carrier radios transmit with 1/52 nd the power of standard 802. 11 a radios and would have similar range. • Use multiple carriers for greater range. 01758 E-5 -UP Proposal 10 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 Robustness • Multi-path does not generate

July 2000 doc. : IEEE 802. 11 -00/175 Robustness • Multi-path does not generate intersymbol interference (with OFDM): rather, it creates fading. • Hopping of carriers can prevent long fades or interference problems. • Fading can also be reduced with antenna diversity. 01758 E-5 -UP Proposal 11 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 PHY Issues • Frequency Lock –

July 2000 doc. : IEEE 802. 11 -00/175 PHY Issues • Frequency Lock – Need sufficient orthogonality for OFDM – Transmitters lock to AP carrier frequencies – Receivers track each carrier • Symbol Timing – Alignment must preserve guard intervals – Both open-loop and closed-loop solutions are possible • Power Control – Needed for uplink – Use open-loop control scheme 01758 E-5 -UP Proposal 12 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 Topology • 5 -UP mode controlled

July 2000 doc. : IEEE 802. 11 -00/175 Topology • 5 -UP mode controlled by AP. • 5 -UP stations communicate via AP. • Ad-hoc mode requires either master election, or a protocol subset profile. • Peer to peer (direct link) possible, but complex for multiple simultaneous pairs 01758 E-5 -UP Proposal 13 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 5 -UP MAC Concepts • Control

July 2000 doc. : IEEE 802. 11 -00/175 5 -UP MAC Concepts • Control Channel – At least one logical carrier for DCF uplink – Used for management and control • Data Channel – (simplified) DATA frames on remaining carriers • AP assigns ID for device/carrier group • Poll via 5 -UP Beacon (look for ID) • Potential for multiple 5 -UP Beacons/PCF 01758 E-5 -UP Proposal 14 Mc. Farland, Chesson, Atheros Communications

July 2000 doc. : IEEE 802. 11 -00/175 Summary • Carrier groups can be

July 2000 doc. : IEEE 802. 11 -00/175 Summary • Carrier groups can be added to 802. 11 a – Additional capabilities for OFDM radios – Enable low-power/cost/speed devices • 108 Mb/s data rate (or more) • Improved Qo. S – Bandwidth assignments via carrier groups – Fewer slots leads to lower jitter, less overhead • Unified approach to expand the market for wireless LANs 01758 E-5 -UP Proposal 15 Mc. Farland, Chesson, Atheros Communications