1. LB97 Coex: Duplicate DSSS
Month Year
doc.: IEEE yy/xxxxr0
September 2007
LB97 Coex: Duplicate DSSS
Date:
Authors:
Ali Raissinia, Qualcomm, Inc.
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
September 2007
Abstract
This presentation provides the background for adding Non-HT Duplicate DSSS waveform for use as a protection mechanism for 40 MHz transmissions in 2.4 GHz band
Ali Raissinia, Qualcomm, Inc.
John Doe, Some Company

3. 20/40MHz Coexistence in 2.4 GHz
September 2007
20/40MHz Coexistence in 2.4 GHz
Background
On July 7 TGn voted to adopt doc r10 that addresses 20/40 MHz coexistence for the 2.4 GHz band
Summary of mechanism:
HT AP needs to scan to establish a new 20/40 MHz BSS
HT STA needs to scan for presence of non-HT STAs in “affected 40MHz channels” and set FortyMHz intolerant bit to limit 40 MHz transmissions
Scan period still TBD
Short scan time adds too much unnecessary overhead
Long scan time makes the mechanism ineffective
Ali Raissinia, Qualcomm, Inc.

4. Non-HT Duplicate DSSS Protection
Month Year
doc.: IEEE yy/xxxxr0
September 2007
Non-HT Duplicate DSSS Protection
Non-HT duplicate DSSS protection frame is an optional complement to r10 mechanisms
In between scanning periods, 40 MHz transmissions can be protected to avoid clobbering non-HT STA transmissions in the secondary channel
Additional protection against non-HT STAs (11b/g) operating in secondary channel 5 or 10 MHz away
Proposed change is minimal
Existing spec already provides protection using non-HT duplicate transmissions with OFDM waveforms
New proposal includes small change in subclause (i.e., Protection Mechanisms, Table 9-7) and brief text in clause 20 describing the duplicate DSSS waveform
Ali Raissinia, Qualcomm, Inc.
John Doe, Some Company

5. September 2007
Motion
Propose to adopt the comment resolutions for CID 25, 1538, 1539, 1848, and 2906 in doc. 07/2477r1
Yes No
Abstain
Ali Raissinia, Qualcomm, Inc.

6. September 2007
Backup
Ali Raissinia, Qualcomm, Inc.

7. September 2007
Protection Details
Suggested MAC protection for 40 MHz transmission in the current draft refers to use of clause 15 or 18, when
Use_Protection_bit set to 1
Indicating presence of 11.b devices associated in BSS, AND
HT Protection field set to 1
Indicating knowledge of at least one non-HT device in OBSS, OR
HT Protection field set to 3
indicating at least one non-HT device associated within BSS
Protection seems adequate for
Case when HT Protection field set to 3 but NOT for
Case when HT Protection field set to 1
Ali Raissinia, Qualcomm, Inc.