doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

November 2011

Slide 1

Enablement in 5GHz for FILSDate: 2011-11-07

Authors:

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

November 2011

Slide 2

Abstract

Ideas on Fast Initial Link Set-Up within the 5GHz band via enablement on a different channel.

To be used to stimulate discussion in joint 802.11 REG/ai session

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

November 2011

Slide 3

The Goal

• Understand the idea to expedite AP discovery in 5GHz• Discuss the design space under the constrain to have a

solution which does not interfere with “primary users”• Do not limit the design scope by a country-specific

regulation. Rather consider options enabling different approach in a “region-specific” manner

• Understand the limitations of regulation in certain countries as they exist today

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

November 2011

Slide 4

Idea• 5GHz part operates “as known” Master

device w/ channel sensing• 2.4GHz part asks 5GHz part which

channel are in use (or is told) „real time synchronization of that shared knowledge“

• Non-AP STA conducts active scanning in 2.4GHz band receives valid 5GHz channel list

• Option a) verify this information via passive scanning on specific 5GHz channel

• Option b) directly start link set-up on 5GHz channel

• Continue w/ regular 5GHz operation

Single Device / Box

2.4 GHz AP

5 GHz APInternal Mgmt. Not

accessible by user

Non-AP STA2.4 & 5 GHz

operation

Active scan receive

5GHz channel list

Optio

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• Non-AP STA is under the control of the master (single device)

• Open issues:• Enabling signal is not received in 5GHz channel• Different propagation characteristics of different

frequency bands larger tranmission range of 2.4GHz as compared to 5GHz

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

Enabling signal not received in 5GHz band

• Not a technical issue; constrains imposed by regulation– FCC 15.202: “… Master devices marketed within the United

States must be limited to operation on permissible part 15 frequencies. ...“

– Europe: Not sure; could not find a similar statement. Just the “operation under the control of a master” is required.

– Possible approach: specify standard for this feature to work only in specific regulatory domains (per given annex).

• Does not matter if we “verify” via passive scanning– as in this case, it is legally not an enabling-signal but a hint where

to look for the beacon. – Enablement is legally done via beacon reception as today

• BUT: Could work with FCC constrains if enabling signal is received in any 5GHz channel

November 2011

Slide 5

Is my under-standing of 15.202 correct?

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

Different transmission ranges of 2.4 & 5GHz

• This is a severe technical issue. We might receive an enabling signal at a distance far away from the master device (AP) which is not covered by the sensing requirements for 5GHz operation

• If legislation says that a slave (non AP-STA) must not emit any radiation unless the controlling master device has verified that operation in a specific frequency is permissible (at the location of the slave), we will have to verify via passive scanning.

• Are there other concepts, e.g. database-based information, that can be used (also for operation in other bands i.e. TVWS) ?

November 2011

Slide 6

My understanding is that Europe and US are to restrictive

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

Summary• Statements to be verified based on discussion w/ 802.11

REG

• “enablement” outside the frequency band of concern (here 5GHz) requires– Verification via passive scanning for 5GHz operation (sensing

based detection of primary) due to• Different propagation range of signal• Regulatory requirements

– May work for database-based approaches Talk to 11af

• „Enablement“ inside the 5GHz frequency band seems to be possible; not verification via passive scanning required.

November 2011

Slide 7

doc.: IEEE 802.11-11/1510r0

Submission Marc Emmelmann, FOKUS

November 2011

Slide 8

References• http://www.unwantedemissions.com/47cfr/current/47C

FR015.pdf

• FCC TCB slides discussing FCC KDB 59428– http

://www.fcc.gov/oet/ea/presentations/files/apr11/3b.SoftwareConfigurationControl-RDJS.pdf 

– FCC KDBs 594280 and 178919 are about permissible changes and client devices

• http://transition.fcc.gov/oet/ea/eameasurements.html– is a list of KDBs regarding testing procedures

• http://transition.fcc.gov/oet/ea/presentations/files/oct11/3RF-Exposure-Procedures-Update-102611-KC.pdf– is a presentation on RF Exposure Procedures