Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [802.19] 40MHz 802.11n Bluetooth Sim Pamameters

Title: Re: [802.19] 40MHz 802.11n Bluetooth Sim Pamameters
The real problem comes when you have independent Bluetooth devices (e.g., mobile phone, headset, and media player) close to a PC without Bluetooth. The Bluetooth devices have no way of interacting with the 802.11 network and the 802.11n coexistence methods do not attempt to recognize presence of Bluetooth devices and the Bluetooth devices just see more interference when 40 MHz channels are being used. Also, the current mechanisms in Bluetooth devices to detect 802.11 traffic may not be able to identify the lower power 40 MHz signals even though they may cause interference. Bluetooth devices close to the PC may also disrupt the 40 MHz 802.11n traffic more as well.

Not a good situation for either network.

Regards, John


On 6/27/08 12:10 PM, "Benjamin A. Rolfe" <ben@xxxxxxxxxxxxxx> wrote:

Sure, that fits what I had in mind.  Any of the low bit rate BT devices currently so prevalent.
(I've got a BT headset, mouse, and connection to my PDA going on my PC right now with 802.11g).
Tnx.  
-Ben

----- Original Message -----
 
From:  Bill  Shvodian <mailto:bill.shvodian@xxxxxxxx>  
 
To: Benjamin A. Rolfe <mailto:ben@xxxxxxxxxxxxxx>  
 
Cc: Reuss, Ed <mailto:ed.reuss@xxxxxxxxxxxxxxx>  ; Shellhammer,  Steve <mailto:sshellha@xxxxxxxxxxxx>  ; ppiggin@xxxxxxxxxxxx ; mjlynch@xxxxxxxxxx ; Mark.austin@xxxxxxxxxxxx ; stds-802-19@xxxxxxxx ; nada.golmie@xxxxxxxx ; eldad.perahia@xxxxxxxxx ; Joseph.Levy@xxxxxxxxxxxxxxxx ;  bheile@xxxxxxxx ;  john.barr@xxxxxxxxxxxx ; swhitesell@xxxxxxxx ; necati.canpolat@xxxxxxxxx ; I_reede@xxxxxxxxxxxx ; carl.stevenson@xxxxxxxx ; Matt.Smith@xxxxxxxxxxx ; vivek.g.gupta@xxxxxxxxx ; bkraemer@xxxxxxxxxxx ; Jones, Vk <mailto:vkjones@xxxxxxxxxxxx>  ;  david.cypher@xxxxxxxx ; sli@xxxxxxxxxx
 
Sent: Friday, June 27, 2008 9:21 AM
 
Subject: Re: 40MHz 802.11n Bluetooth Sim  Pamameters
 

It would also be useful to consider Bluetooth mice and  keyboards as well.  I was at a standards meeting this week and someone  told me that they could see 15 Bluetooth mice when they scanned for  theirs.

Bill

 
On Fri, Jun 27, 2008 at 6:09 PM, Benjamin A. Rolfe  <ben@xxxxxxxxxxxxxx> wrote:
 

 
Very good points, Ed,  
I wasn't thinking broadly enough: In my case I  was thinking about a single user with multiple devices, but it is very  realistic (and more typical) that you have two users sitting at the same  table, two PCs, two headsets, etc.  Many times you see two  people sharing a table at the coffee shop with the  PCs back-to-back, thus the antenna separated by a few inches but  without out-of-band signaling available to coordinate.  One (or  both) user is streaming video from his HD video cam to his PC, for  example, using a lot of bps.  Perhaps they are sharing content. The  point is doing more than internet access.
 
 
Another question: Can we "dial back" BW usage  in a similar way that we can use transmit power control to reduce the  spectral footprint to only as big as we need? Having read through the 802.11n draft sections on 40MHz mode  (thanks for the right section # references BTW), I am still a bit confused  as to how selection can happen.   Can we mix 20MHz and 40MHz nodes  at the same time?  If the added BW is not needed for data rate or link  margin, will a node drop back to 20 MHz?   Using transmit power  control to tune the link has proven to be a good thing for spectral  effectiveness and coexistence, and it seems to me the same idea applied  to BW management might be useful as well.  Is this possible  with the current 'n' ?  I'm not so sure it will help, mind you.  Potentially with the wider BW you would need lower power to get the same  link margin, also reduces the effective SoI. Surely someone has run these  trade-offs?  The results would be interesting (and relent to a  coexistence discussion!).

Thanks
-B
 
 
 
 

-----  Original Message -----
 
From:  Reuss, Ed <mailto:ed.reuss@xxxxxxxxxxxxxxx>  
 
To:  Shellhammer, Steve <mailto:sshellha@xxxxxxxxxxxx>  ; Benjamin A. Rolfe <mailto:ben@xxxxxxxxxxxxxx>  ; ppiggin@xxxxxxxxxxxx ; mjlynch@xxxxxxxxxx ; Mark.austin@xxxxxxxxxxxx ; stds-802-19@xxxxxxxx  ; nada.golmie@xxxxxxxx ; eldad.perahia@xxxxxxxxx ; Joseph.Levy@xxxxxxxxxxxxxxxx ; bheile@xxxxxxxx ; john.barr@xxxxxxxxxxxx ; swhitesell@xxxxxxxx ;  necati.canpolat@xxxxxxxxx ; I_reede@xxxxxxxxxxxx ; carl.stevenson@xxxxxxxx ; Matt.Smith@xxxxxxxxxxx ; vivek.g.gupta@xxxxxxxxx ; bkraemer@xxxxxxxxxxx  ; Jones, Vk <mailto:vkjones@xxxxxxxxxxxx>  ; bill.shvodian@xxxxxxxx ; david.cypher@xxxxxxxx ; sli@xxxxxxxxxx
 
Sent:  Friday, June 27, 2008 8:13 AM
 
Subject:  RE: 40MHz 802.11n Bluetooth Sim Pamameters
 

 
 

Hi Steve,  Ben:

 
 

These are nice  use cases with one caveat. If the PC contains both the BT radio and the  802.11n radio, then I would expect that most manufacturers would implement  one of the 2, 3 or 4 wire "Coexistence Bus" mechanisms that are available  for many BT, Wi-Fi and BT/Wi-Fi combo products available today. These  collaborative coexistence methods will work just as well for 40 MHz  transmissions as well as for 20 MHz transmissions.

 
 

So we have two  alternatives:
  1. Make sure that neither the  simulations nor the lab experiments use any form of collaborative  coexistence mechanism.  
  2. Modify the use case so that  the user is watching streaming videos via their PC while talking on the  cell phone with a headset, under the assumption that there will be no  form of collaboration between the PC and the cell phone or the PC and  the headset.


 
 

Either is  acceptable to me.

 
 

-- Ed  Reuss

 
 
 




From:  Shellhammer, Steve [mailto:sshellha@xxxxxxxxxxxx]
Sent: Thursday, June 26, 2008 8:43  PM
To: Benjamin A. Rolfe;  ppiggin@xxxxxxxxxxxx; mjlynch@xxxxxxxxxx; Mark.austin@xxxxxxxxxxxx; stds-802-19@xxxxxxxx;  nada.golmie@xxxxxxxx; eldad.perahia@xxxxxxxxx; Joseph.Levy@xxxxxxxxxxxxxxxx; bheile@xxxxxxxx; john.barr@xxxxxxxxxxxx; swhitesell@xxxxxxxx;  necati.canpolat@xxxxxxxxx; I_reede@xxxxxxxxxxxx;  carl.stevenson@xxxxxxxx; Matt.Smith@xxxxxxxxxxx; vivek.g.gupta@xxxxxxxxx; bkraemer@xxxxxxxxxxx;  Jones, Vk; bill.shvodian@xxxxxxxx; david.cypher@xxxxxxxx; sli@xxxxxxxxxx
Cc: Reuss, Ed
Subject: RE: 40MHz 802.11n Bluetooth  Sim Pamameters

 
 

Ben,

 
 

             If you would like to make modifications to the version I just sent out  that Vinko edited, feel free.  We can discuss the various edits in  Denver.

 
 

Regards,

Steve

 
 
 




From:  Benjamin A. Rolfe [mailto:ben@xxxxxxxxxxxxxx]
Sent: Wednesday, June 18, 2008 3:17  PM
To: Shellhammer,  Steve; ppiggin@xxxxxxxxxxxx; mjlynch@xxxxxxxxxx; Mark.austin@xxxxxxxxxxxx; stds-802-19@xxxxxxxx;  nada.golmie@xxxxxxxx; eldad.perahia@xxxxxxxxx; Joseph.Levy@xxxxxxxxxxxxxxxx;  bheile@xxxxxxxx; john.barr@xxxxxxxxxxxx; swhitesell@xxxxxxxx;  necati.canpolat@xxxxxxxxx; I_reede@xxxxxxxxxxxx;  carl.stevenson@xxxxxxxx; Matt.Smith@xxxxxxxxxxx; vivek.g.gupta@xxxxxxxxx; bkraemer@xxxxxxxxxxx;  Jones, Vk; bill.shvodian@xxxxxxxx; david.cypher@xxxxxxxx; sli@xxxxxxxxxx
Cc: Reuss, Ed
Subject: Re: 40MHz 802.11n Bluetooth  Sim Pamameters

 
 
 

A couple questions for the  group:
 

- I think it would be a good  idea to add usage models:
 

1. The VoIP via the internet  model. The user has a BT headset, using a laptop PC to Skype over the  internet, while at the same time (in user time frame) browsing the web,  transferring files and so on.  In this  scenario the STA is much  closer to one end of the BT link (10cm or less).  Since I know  this can be done with 11g and BT without one saturating the other, I feel  this is a realistic scenario for 11n - make sense?
 

 
 
 

2. Streaming video and BT  sound: The user is streaming video to his personal media device and  listening via a hifi stereo BT headset.   Same thing - two ends  of the 11n and BT links are very close.
 

 
 
 

- would it make sense to have  a less than full duty cycle scenario for 11n.  For the "internet  user" scenario, I suspect the 11n duty cycle would be quite a bit less  than the maximum, because of the backbone access bottle nck. So if I  assume a bottle neck of 6Mbps what would be a reasonable duty  cycle?
 

 
 
 

- For the 11n guys: with  maximum payload transfer rate, what is the effective on-air duty cycle for  11n at full speed (considering necessary IFSes, average back-offs,  etc.)?  What would be reasonable for the 6Mbps bottle neck  scenario?
 

 
 
 

- For the BT guys, what is  expected on-air duty cycle for Bluetooth (a) normal voice and (b) HiFi  sound?
 

 
 
 

If I get some input, I can  write up the scenarios.
 

-Ben
 

 
 
 

 
 


 

----- Original Message -----  
 

From: Shellhammer, Steve <mailto:sshellha@xxxxxxxxxxxx>  
 

To: ppiggin@xxxxxxxxxxxx ; mjlynch@xxxxxxxxxx ;  Mark.austin@xxxxxxxxxxxx ; stds-802-19@xxxxxxxx ; nada.golmie@xxxxxxxx ; eldad.perahia@xxxxxxxxx ; Joseph.Levy@xxxxxxxxxxxxxxxx ; bheile@xxxxxxxx ; john.barr@xxxxxxxxxxxx ; swhitesell@xxxxxxxx  ; necati.canpolat@xxxxxxxxx ; ben@xxxxxxxxxxxxxx ; I_reede@xxxxxxxxxxxx ; carl.stevenson@xxxxxxxx ; Matt.Smith@xxxxxxxxxxx ; Shellhammer, Steve <mailto:sshellha@xxxxxxxxxxxx>  ; vivek.g.gupta@xxxxxxxxx ; bkraemer@xxxxxxxxxxx ; Jones, Vk <mailto:vkjones@xxxxxxxxxxxx>  ; bill.shvodian@xxxxxxxx ; david.cypher@xxxxxxxx ; sli@xxxxxxxxxx  
 

Sent:  Wednesday, June 18, 2008 12:57 PM
 

Subject:  40MHz 802.11n Bluetooth Sim Pamameters
 

 
 
 

On the Monday  conference call I volunteer to begin a simple Simulation Parameters  document for evaluating the impact of 40 MHz 802.11n on Bluetooth.   I have posted a first version of that document on the server  at,
 

 
 
 

https://mentor.ieee.org/802.19/file/08/19-08-0018-00-0000-40mhz-11n-bluetooth-sim-parameters.doc <https://mentor.ieee.org/802.19/file/08/19-08-0018-00-0000-40mhz-11n-bluetooth-sim-parameters.doc>

 

 
 
 

If anyone wants to make any  modifications or additions you can add your name to the list of authors  and revise the document.  Hopefully we can agree on this simple  document via email.  If someone feels we need a conference call  before the Denver meeting to discuss this please notify  me.
 

 
 
 

Thanks,
 

Steve
 

 




CONFIDENTIALITY  NOTICE: This e-mail transmission, and any documents, files or previous  e-mail messages attached to it, may contain information that is  confidential and/or legally privileged. If you are not the intended  recipient, or a person responsible for delivering it to the intended  recipient, please DO NOT disclose the contents to another person, store or  copy the information in any medium, or use any of the information  contained in or attached to this transmission for any purpose. If you have  received this transmission in error, please immediately notify the sender  by reply email or at mailto:privacy@xxxxxxxxxxxxxxx, and destroy the original  transmission and its attachments without reading or saving in any manner.  

For further information about Plantronics - the Company, its  products, brands, partners, please visit our website www.plantronics.com <http://www.plantronics.com> .  




--  
John R. Barr (John.Barr@xxxxxxxxxxxx)
Director, Standards Realization - <http://www.motorola.com>
Vice Chairman of the Board, Bluetooth SIG - <http://www.bluetooth.org>
(847) 576-8706 (office) +1-847-962-5407 (mobile) (847) 576-6758 (FAX)