1. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 1 April, 2008 NICT Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Questions/Comments on AV-OFDM MAC] Date Submitted: [April 16, 2008] Source: [Chang woo Pyo, Zhou Lan, Fumihide Kojima, Tuncer Baykas, Chin Sean Sum, Junyi Wang, Azizur Rahman, Hiroyuki Nakase, Hiroshi Harada, Shuzo Kato] Company [National Institute of Information and Communications Technology (NICT)] Address 1 [3-4 Hikari-no-oka, Yokosuka-shi, Kanagawa 239-0847, Japan] Voice 1 :[+81-46-847-5074], FAX 1 : [+81-46-847-5440] E-Mail[] Re: [In response to TG3c Call for Proposals (IEEE P802.15-07-0586-02-003c)] Abstract: [Questions/Comments on AV-OFDM MAC] Purpose: [To be considered in TG3C baseline document.] Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributors acknowledge and accept that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 2 April, 2008 NICT Summary Identify the “need-to-clarify” items in AV- OFDM

3. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 3 April, 2008 NICT SCAN Comments are shown in the next page SCAV-OFDM SCAN CHs4 CHs (appendix A)12 LRP CHs (appendix A) SCAN Procedure- SCAN by Omni /Quasi- Omni beams (The number of Quasi-omni beams is upto 4) SCAN by Omni SCAN informationChannelRatingList Piconet detectionBy beacon of base (common) rate – LRP1 (50Mbps) By beacon of base rate (TBD) Channel Switching Time (pPHYChannelSwitchTi me) 100us1000us Channel clear assessment (CCA) time 5us9us

4. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 4 April, 2008 NICT Comments for AV-OFDM (related to SCAN) Comment 1 –Which channel is used to scan in LRP channels (LRP1, LRP2, or LRP3) Comment 2 –What is the definition of omni - covering 360 degree or part of 360 degree –If omni is covering the part or 360 degree, how many directions are supported by each device Comment 3 – What is the definition of base rate of beacon Comment 4 –The reason of channel switching time of 1000us and CCA time of 9us

5. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 5 April, 2008 NICT Starting a piconet Comments are shown in the next page SCAV-OFDM Channel Selection With least amount of interference defined in 802.15.3b Implementation dependent Superframe1.Beacon : -Upto 4 Omni/Quasi-omni beacons (Directional beacons) -Base (common) rate – LRP1 1.Beacon : -Omni beacon -Base rate (TBD) 2. CAP : - Control signals for the same rate of beacon (base rate) - Data for any other rate - Sub-CAPs for multiple Quasi- omni beacons 2. CAP - 4 LRP rates (2.5, 3.8, 5.1, and 10.2Mbps) 3. CTAP : All available rates3. CTAP : HRP, LRPs and directional LRPs Superframe resolution 1us

6. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 6 April, 2008 NICT Comments for AV-OFDM (related to starting a piconet) Comment 5 –The reason of channel selection not complying with 15.3 Comment 6 –Does AV-OFDM support directional beacons Comment 7 –What is the date rate for beacon (related to comment 2) Comment 8 –What data rates are supported in CAP

7. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 7 April, 2008 NICT Association Comments are shown in the next page SCAV-OFDM PNC-DEV Association Association in CAP Base (common) rate for association Base rate (TBD) for association Qmni/Quasi-Omni antennaOmni antenna DEV-DEV Association Association in CTAP- Base (common) rate- Omni/Quasi-Omni antenna-

8. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 8 April, 2008 NICT Comments for AV-OFDM (related to Association) Comment 9 –What data rate is used for association Comment 10 –AV-OFDM is no procedure of DEV-DEV association

9. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 9 April, 2008 NICT Beamforming Comments are shown in the next page SCAV-OFDM Beamforming Ant. Beamforming Ant. or Sectorized Ant. Beamforming Ant. or upto 8 directional Ant. Beamforming operations PNC and DEV beamforming DEV and DEV beamformingNo description for DEV and DEV beamforming PNC and DEV beamforming -Beamforming in CTA -Symmetric/Asymmetric Tx/Rx ant. beamforming support -Periodical beam-tracking -Omni beacon only -RX diversity training field in preamble DEV and DEV beamfoming -Beamforming in CTA -Symmetric/Asymmetric Tx/Rx ant. beamforming support -Periodical beam-tracking ?

10. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 10 April, 2008 NICT Comments for AV-OFDM (related to Beamforming) Comment 11 –What is the difference between beamforming antenna and directional antenna Comment 12 –What is the function of RX diversity field in preamble Comment 13 –Does AV-OFDM support symmetric and asymmetric Tx and Rx ant. in beamforming

11. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 11 April, 2008 NICT Channel probing Comments are shown in the next page SCAV-OFDM Channel probingOptional function? Channel probing operations PNC to DEV and DEV to DEV channel probing in CTA In CTA ? Data used for measurement Regular data frame? Way to feedbackMAC header of Imm-ACK or Dly-ACK Channel probing response command ? Channel status information RSSIr, SINR, Suggested CES length, FER RSSI, SNR, recommended PHY mode

12. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 12 April, 2008 NICT Comments for AV-OFDM (related to channel probing) Comment 14 –Does AV-OFDM support channel probing –If support, how to perform channel probing

13. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 13 April, 2008 NICT Streaming Comments are shown in the next page SCAV-OFDM Streaming in SFCTAP Maximum frame size 8M octets7M octets for HRP, 4K octets for LRP Minimum fragment size 512 octetsTBD Aggregation- Option - Maximum subframe size for aggregation = 1M octets - Available number of aggregated subframes = 8 - Two types of aggregation support 1) Standard aggregation 2) low latency aggregation - Option - Maximum subframe size for aggregation = 1M octets - Available number of aggregated subframes = 7 Block ACK- Retransmission of aggregated subframes - ACK group (usage of ACK group is TBD) Directional ACKACK is the same data rate of streamDirectional ACK (Directional LRP)

14. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 14 April, 2008 NICT Comments for AV-OFDM (related to streaming) Comment 15 –What is the value for the minimum fragment size Comment 16 –What is the definition of ACK group Comment 17 –Details of retransmission procedure in AV-OFDM Comment 18 –What is the data rate for directional ACK Comment 19 –The reason of directional ACK not complying to 15.3b ACK information of directional ACK is included in header not payload

15. doc.: IEEE 802.15-08-0240-00-003c Submission Slide 15 April, 2008 NICT Appendix: Channel Index SCAV-OFDM CHNL_IDChannel indexCHNL_IDHRP Channel Index LRP Channel Index 1CH11HRP1LRP1 2CH22HRP2LRP1 3CH33HRP3LRP1 4CH44HRP4LRP1 5HRP1LRP2 6HRP2LRP2 7HRP3LRP2 8HRP4LRP2 9HRP1LRP3 10HRP2LRP3 11HRP3LRP3 12HRP4LRP3