1. Enterprise Simulation Scenario
September 2006
doc.: IEEE /1458r0
Sept. 2009
Enterprise Simulation Scenario
Date:
Hart (Cisco Systems)
Joonsuk Kim, Broadcom Corp.

2. Improvements to the enterprise simulation scenario
September 2006
doc.: IEEE /1458r0
Sept. 2009
Improvements to the enterprise simulation scenario
Situation
11ac has 5 or 6 channels at 5GHz whereas 11n had 12 channels. Overlapping APs are much more likely with 5 or 6 channels.
The Functional Requirements and Evaluation Methodology 09/451r7 includes:
“Note) It is encouraged that TGac technology proposals describe its impact on OBSS”
Complication
This Note will lead to un-comparable qualitative comments.
In San Francisco we straw-polled a specific change that would modify the Note to make it more quantitative, with results Y34, N0, A30
This is a large number of Abstains
Key Line
We solicit doubts and questions so as to bring an improved motion in Hawaii that changes to the Note.
Hart (Cisco Systems)
Summary
Joonsuk Kim, Broadcom Corp.

3. There are only five or six 80 MHz channels
September 2006
doc.: IEEE /1458r0
Sept. 2009
There are only five or six 80 MHz channels
There are five 80MHz channels at 5 GHz
36-48, 52-64, , ,
Plus a sixth, , with a regulatory change
Typical channel plan with six channels is:
Hart (Cisco Systems)
Joonsuk Kim, Broadcom Corp.

4. So we expect two overlapping BSSs
September 2006
doc.: IEEE /1458r0
Sept. 2009
So we expect two overlapping BSSs
APs co-channel with the (0,0) AP are at
(-20,-40), (20,40)m [44m range]
(-40,40), (40,40)m [57m range]
(0,60), (-60,0)m [60m range]
Now range with -76dBm CCA (for 80MHz) is 50m:
17dBm + 3dBi - 47dB[1m] - 20log10(5m/1m) - 35log10(50m/5m) = -76dBm
With multistorey deployments, 20dBm TX power, 6dBi antennas, cubes, realistic sensitivities, 10 or 20m breakpoint, the actual overlap is worse
But let’s assume 2 overlapping BSSs for simplicity
Hart (Cisco Systems)
Joonsuk Kim, Broadcom Corp.

5. Proposal: let’s allow comparability in OBSS behavior
September 2006
doc.: IEEE /1458r0
Sept. 2009
Proposal: let’s allow comparability in OBSS behavior
Uplink/downlink MU-MIMO / SDMA and OFDMA are valuable technologies that we should be exploring, yet they are more challenging in an OBSS world
We should include OBSS as an “impairment” because otherwise there is a risk we will make suboptimal design choices based on false optimism
The simplest proposal is to triplicate the APs and clients in scenario #4, keep the first copy at (0,0), translate the second copy by (20,40) and translate the third copy by (-20,-40)m
Note: multiple APs is more in harmony with Usage Model 2d in 09/161r2
Hart (Cisco Systems)
Joonsuk Kim, Broadcom Corp.

6. Proposed Motion Change the Note in section 4.4 of 09/451 as follows:
September 2006
doc.: IEEE /1458r0
Sept. 2009
Proposed Motion
Change the Note in section 4.4 of 09/451 as follows:
E.g. Note) It is encouraged that TGac technology proposals describe its impact on OBSS. The recommended simulation scenario is the Enterprise Simulation Scenario with the BSS triplicated then each copy translated by (0,0), (20,40) and (-20,-40)m
Y, N, A
Hart (Cisco Systems)
Joonsuk Kim, Broadcom Corp.

7. Soliciting Doubts and Questions
September 2006
doc.: IEEE /1458r0
Sept. 2009
Soliciting Doubts and Questions ?
Hart (Cisco Systems)
Joonsuk Kim, Broadcom Corp.