october 2010 doc.: ieee 802.15 project: ieee p802.15 ... · doc.: ieee 802.15-10-0823-00-0007 tg7...

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

October 2010

Dae-Ho Kim, ETRISlide 1

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

Submission Title: [Comment resolution for T-CID 78]Date Submitted: [October, 2010]Source: [Dae Ho Kim, Tae-Gyu Kang, Sang-Kyu Lim, Il Soon Jang, You Jin Kim] Company [ETRI],

[Sridhar Rajagopal] Company [Samsung Electronics]Address [138 Gajeongno, Yuseong-gu, Daejeon, 305-700]Voice:[+82-42-860-5648], FAX: [+82-42-860-5218], E-Mail:[[email protected]]Re: [Response to LB50 comments]

Abstract: [This document describes about comment resolution for T-CID 78]

Purpose: [Propose to ]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.

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

Comment resolution for T-CID 78

Dae Ho [email protected]

ETRI


October 2010

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

PHY Frame (PPDU) Format and PHY Header

October 2010


HCS

HCS – Right?

• Need to define the exact calculation range of each HCS at subclause 5.4.2.6 • Need to distinguish each HCS name* Additional comments

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

MAC Frame (MPDU) Format

October 2010


FCS

•Subclause 6.2.1.9 FCS field: The FCS is calculated over the MHR and MSDU parts of the frame.

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

VLC Frame Format

October 2010


doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

HCS of PHY and FCS of MAC

October 2010


Preamble

Burst mode, … HCS PHYOption

Frame Control, … MSDU FCS

MHR MAC Payload MFR

PHY Payload = PSDUPHRSHR

HCS of PHR FCS of MAC HCSof option field

• The FCS of MAC covers the MHR and MSDU parts of the frame.• The HCS of PHY covers the PHR

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

T-CID 78

• Comment– PSDU structure is not defined, provide a

figure which shows how the PSDU is created

October 2010


doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

Figure for T-CID 78

October 2010


SHR

Burstmode

Channelnumber

MCSID

PSDUlength ReservedDimmed

OOKPHR

HCS

OptionalFields

PSDU

FLP (101010 …) TDP ~TDP TDP

64 to 16,384 bits

~TDP

60 bits

1 bit 3 bits 6 bits 16 bits 1 bit 5 bits

Tail bits

Compensation length OFCSResync

length

Channel estimation sequence

Subframe length

6 bits 10 bits 4 bits 10 bits 8 bits 8 bits x 3

Variable(0/6/32/8x3)

32 bits

16 bits

Variable(≥124)

Variable

Frame payload

0-aMaxPHYFrameSize

FCS Tail bits

0/16 bits 0/6 bits

Whose FCS and tail bits? MAC or PHY?

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

HCS of PHY header and FCS of PHY

October 2010


Preamble



MHR MAC Payload


HCS of PHR

FCS of PHY

HCSof option field

• The general FCS covers header and payload of the frame. • The FCS covers all fields of frame except itself. So we call Frame Check Sequence.• The general HCS covers only header (except itself). So we call Header Check Sequence.

•If FCS is a part of PHY, FCS has to cover the PHR and the PSDU.

Duplication!!

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

FCS for decoded PSDU - 1

• The FCS is for checking the validity of the decoded PSDU.

October 2010


Preamble



MHR MAC Payload


HCS of PHR FCS for MAC HCS

Duplication!!

FCS

MFR

FCS for decoded PSDU

• It does not need to error check for decoded PSDU. Decoded PSDU means MAC frameand because MAC frame is checked by FCS of MAC. And that is the role of MAC.

• The Data Link Layer(= LLC+MAC) provides the functional and procedural means to transfer data between network entities and might provide the means to detect and possibly correct errors that may occur in the Physical Layer.

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

FCS for decoded PSDU - 2

• The FCS is for checking the validity of the decoded PSDU.

October 2010


Preamble


Frame Control, … MSDU

MHR MAC Payload


HCS of PHR FCS for MAC HCS

What is different?

FCS

FCS for decoded PSDU

• The FCS check can happen in the PHY or the MAC.- No “or”!! Need to exact define!! - FCS is a part of MAC, not PHY.

doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

T-CID 78• PSDU and MSDU

– A SDU (Service Data Unit) is a unit of data that has been passed down from an higher layer to a lower layer and that has not yet been encapsulated into a protocol data unit (PDU) by the lower layer.

– PSDU is a field of PHY and MSDU is a field of MAC.– PSDU and MSDU do not have a structure.

• Comment– PSDU structure is not defined, provide a figure which shows

how the PSDU is created• Accept in principle.• Just we need to explain how the PSDU is created.

– “The PSDU field carries the data of the PHY frame, such as MAC frame, and it has a variable length depending on the length of MAC frame. The MAC frame structure is described in 6.2.1 more in detail.”

October 2010


doc.: IEEE 802.15-10-0823-00-0007

TG7 VLC Submission

Summary

• Current PHY frame format and MAC frame format is exactly right!!– We do not need to use a additional figure

for resolution.– Figure for T-CID 78 makes a only

confusion.• If we want to add a tail bits, we have to

change figure 22, figure 15, and so on.

October 2010


october 2010 doc.: ieee 802.15 project: ieee p802.15 ... · doc.: ieee 802.15-10-0823-00-0007 tg7...

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