March 2008doc.: IEEE 802.11-08/0384r0

IEEE P802.11
Wireless LANs

Minutes of WNG SC March 2008 Session
Date: 2008-03-18
Name / Company / Address / Phone / email
Stephen McCann / Nokia Siemens Networks GmbH & Co KG / Roke Manor Research Ltd, Old Salisbury Lane, Romsey, SO51 0ZN, UK / +44 1794 833341 /


Morning Session Tuesday 08:00 – 10:00

Mobility Management, Stephen McCann (NSN), 11-08-0360r0

WAVE Enhancement, Hyun Seo Oh (ETRI), 11-08-0361r0

Impact of Multi-hop MESH flows on WLANs, Mathilde Benveniste (ETRI), 11-08-0292r0


Morning Session Tuesday 08:00 – 10:00

WNG SC (Wireless Next Generation Standing Committee) meeting called to order by TK Tan.

The IEEE 802 & IEEE 802.11 Policies and Rules were reviewed, together with licensing terms and associated conditions. No comments or objections were noted.

The agenda (11-08-0345r0) was approved by unanimous consent.

The January 2008 Taipei WNG SC minutes (11-08-0122-00-0wng-wng-jan2008-meetingminutes.doc) were approved by unanimous consent.

Mobility Management, Stephen McCann (NSN), 11-08-0360r0

Action: Authors need to talk to Richard Paine about mobility management issues.

Straw Poll: Would you like the authors to come back with more information

in the May meeting:

For: 39, Against: 0, Abstain: 17

Chair: I invite the authors to return in May with some more information.

WAVE Enhancement, Hyun Seo Oh (ETRI), 11-08-0361r0

Chair asked the membership if it is ok for ETRI to present in their format, as opposed

to IEEE format. There were no objections to this.

It will be transferred to the 11-08-0361r0 document later.

V2V : vehicle to vehicle comms

V2I : vehicle to infrastructure

Question (Q): Is this a proposal to IEEE 802.11 of some sort?

Chair: This is just bringing this research to the group. He has already spoken

to the chair of TGp about this.

Presenter: I would like a new study group eventually. I would like some of these technologies to be placed into the IEEE 802.11 standard. More research is still required. Nothing has been implemented yet.

TGp Chair: We cannot change the TGp PAR at the moment and therefore it would have to be a new PAR. It's too late in the TGp standardisation cycle. I feel that this technology is coming and many transportation departments want to try and deploy road side infrastructures.

Q: What are the changes which would have to made to TGp

TGp Chair: IEEE 1609 (upper layer standard) would require changes and perhaps some more things in IEEE 802.11.

Q: regarding TDMA, I think that CSMA is actually one of the strengths of IEEE 802.11 and so I'm very concerned about association and dis-association times for road side infrastructure.

TGp Chair: Yes, but this is why TGp has changed the traditional IEEE 802.11 association protocol.

Q: But TDMA requires a lot of signalling and time for association. I have some big concerns about this.

TGp Chair: OK, well we need to consider this TDMA approach in conjunction with the authors if this presentation.

Impact of Multi-hop MESH flows on WLANs, Mathilde Benveniste (Avaya Labs), 11-08-0292r0

This presentation is a follow up from a presentation in 2007 and the author has done some simulations based on feedback from earlier meetings.

Q: Regarding slide #9, the RTS/CTS situation. After the CTS collision, you see a collision on the ACK. I think this is not so probable as the STA goes into recovery mode.

Answer (A): But if this is Tx Off, then they could collide.

Q: Yes, but since it does not receive the ACK, it would be in recovery.

A: Ok, perhaps its ok for this scenario.

Q: Both CTS and ACKs can cause collisions.

Q: Regarding slide #17, with no RTS/CTS situation, there are 6-7 collisions between A&B and E&F. Again I don't think this is likely as both pairs will have different back-off delays.

A: Remember that you cannot hear the other node, so I think the scenario is ok.

Q: Many times you mentioned about A not hearing B, what does this mean? Is this just the header, or the whole frame itself?

A: Yes, I have taken this into account.

Q: Was RTS/CTS used just for the video traffic.

A: Yes.

Chair: There is a request to stay for a straw poll. Is this ok?

The result showed that only a limited number of people decided to stay

Straw poll: RTS/CTS cannot avert the problems encountered with single-channel meshes?

Q: I think we need a 'don't know' option, otherwise the straw poll is meaningless, as this is quite a complicated subject.

Chair: Actually, I think we need to delay this to the next meeting.


Chair: Move for WNG to adjourn

No objections.

Meeting adjourned at 10:06 ET.

Minutespage 1Stephen McCann, NSN