Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Clarification of frame durations for UWB PHY] Date Submitted: [18 July 2006] Source: [Philip Orlik] Company [Mitsubishi Electric Research Laboratories, Inc.] Voice:[+1 617 261 7570], FAX: [+1 617 621 7550], E-Mail:[porlik@merl.com] [Ben Rolfe] Company [] Voice:[+1 408 395 7207], FAX: [], E-Mail:[ben@blindcreek.com] [Yihong Qi] Company [National Institute of Information and Communications Technology] Voice:[+81 46 847 5092], FAX: [], E-Mail:[yhqi@ieee.org] Re: [] Abstract: [Describes suggested changes to correct and clarify clause 6.4.2.1 and resulting MAC timings which depend on PHY frame duration, and identify issues for TG discussion.] Purpose: [Collect task group input and concurrence for directing technical editors.] 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 contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Clarification of frame durations for UWB PHY

2. PHY Frame Duration Calculating PHY frame duration for UWB PHY Clarification of frame durations for UWB PHY

3. Objective • Review D3 Clause 6.4.2.1 • Validate correctness • Ensure consistency with other sections • Standardize nomenclature with 15.4/4b • Fix collateral items discovered in review Clarification of frame durations for UWB PHY

4. Objective • 06/276 : Method of determining PHY frame duration needed for MAC timing: • macAckWaitDuration and macMaxFrameTotalWaitTime depend on phyMaxFrameDuration, phySHRDuration • phyMaxFrameDuration, phySHRDuration different for UWB PHY than 15.4/4b • Draft 3 incorporates text and eqn. from 06/276r3 • Includes errors and Inconsistent nomenclature • Can be expressed more simply and clearly Clarification of frame durations for UWB PHY

5. Nomenclature Changes • To be consistent: • TBody => TPSDU • Tpreamble => TSHR • NDsym => NSFD • NPHYHDR => NPHR • NPPDUoctets => NPSDUoctets • Associate with PIB names an PHY Service parameter names. Clarification of frame durations for UWB PHY

6. Errors and Simplification • NPreambleSymbols has wrong values in list • NPPDUOctets is constant: aMaxPHYPacketSize = 127 octets • In Tpreamble ,FDR s/not apply to NpreambleSymbls • RFEC is either 0.44 or .087 • NPHYHDR should be 16 (bits); • NsymPerOctet should be 8 (1 bit/sym); • FDR mis-applied in TPHR • NDsym not clear; • PHR is sent at nominal 1Mbps data rate, not preamble symbol rate. • CCA time got broken • replace "default CCA symbol duration" with "symbol duration of nominal data rate of 1Mbps“ • Use nanoseconds instead of microseconds to be consistent with tables 39a &39b Clarification of frame durations for UWB PHY

7. Clarification of frame durations for UWB PHY

8. Clarification of frame durations for UWB PHY

9. Expresss phySHRDuration in symbols(Tpsym) • Current Text: The PHY PIB attribute phySHRDuration is given by the above formula as phySHRDuration = TSHR + TPHR • Becomes: The actual time for the SHR duration is (refer to 6.4.2): phySHRDurationηs= TSHR + TPHR The PHY PIB attribute phySHRDuration then, given in symbols using Tpsym, is phySHRDuration = (TSHR + TPHR) / Tpsym … Clarification of frame durations for UWB PHY

10. Fix a macAckWaitDuration Old: assume 1 octet PHR, 5 octect ACK macAckWaitDuration = aTurnaroundTime phy + SHRDuration + ceil(6* phySymbolsPerOctet); New: adjust for 2 octet PHR macAckWaitDuration = aTurnaroundTime phySHRDuration + ceil(7* phySymbolsPerOctet); • With fix to phySHRDuration on prior slide, noting this is “close enough” (see 06/276r3 for explanation) Clarification of frame durations for UWB PHY

11. Colateral Issues Found:Unintended Consequences? • Tables 39a & 39b • Code Length 127 only used with PRF 64MHz • PRF 4,16 used only with Code Length 31 • Propose changes to Tables 39a & 39b to include use of length 127 code at lower PRFs. • 4b-D6 uses term “preamble sequence” for what 4a calls “Sync” in SHR. • Changes regarding optional CCA (06/290r0) • macMaxFrameTotalWaitTime Should be in symbol times, not absolute time. Clarification of frame durations for UWB PHY

12. Time to Symbol Counts • 7.4.2 in Draft 3, Page 94, Line 57: • Change: • macMaxFrameTotalWaitTime = phyMaxFrameDurationηs • to: • macMaxFrameTotalWaitTime = phyMaxFrameDurationηs /Tpsym • where Tpsym is from table 39b appropriate for the channel, PRF and preamble code. Clarification of frame durations for UWB PHY

13. To Do • Implication on LIFS/SIFS • Current LIFS implies very low duty cycle for higher data rates • Noted and agreed this is OK. • Resolve issues with Tables 39a & 39b • Missing codes for lower PRFs • Discussed and agreed OK, no change. • Include changes per 06/290r0 • Addressed NICT comments on CCA mode 6. Done Done Done (for 6.4.1.1) Clarification of frame durations for UWB PHY