doc.:ieee 802.11-09/0536r0 submission may 11th, 2009 slide 1 obss issue in 802.11ac authors: date:...
TRANSCRIPT
May 11th, 2009
Slide 1
doc.:IEEE 802.11-09/0536r0
Submission
OBSS issue in 802.11ac
Authors:
Name Affiliations Address Phone email Yasushi Takatori NTT 1-1 Hirkarinooka, Yokosuka-shi,
Kanagawa, Japan, 239-0847 +81 46 859 8596 [email protected]
Kentaro Nishimori NTT 1-1 Hirkarinooka, Yokosuka-shi, Kanagawa, Japan, 239-0847
+81 46 859 8266 [email protected]
Shouichi Kitazawa ATR 2-2-2 Hikaridai, Seika-cho, Kyoto, Japan, 619-0288
+81 774 95 1565 [email protected]
Date: 2009-05-11
May 11th, 2009
Slide 2
doc.:IEEE 802.11-09/0536r0
Submission
Introduction
• More than 1 GBps throughput with multiple STAs and more than 500Mbps throughput for each STA are required in 11ac.
• Following new technologies are likely to be used
– Higher order MIMO (> 4x4)
– Spatial Division Multiple Access (SDMA) with more than 4 AP antennas
– Larger Bandwidth (80 MHz mode)
– Multi frequency channel • Use multiple 20 MHz channels across multiple users.
• Increase in the number of APs / STAs is expected.
May 11th, 2009
Slide 3
doc.:IEEE 802.11-09/0536r0
Submission
BackgroundGiga-bit wired network is proliferating. Giga-bit wireless access is very attractive for both the very high data rate services such as IP-TV.Efficient aggregation function is attractive for low data rate services also such as VoIP services.
0.1
1
10
100
1000
10000
1975 1985 1995 2005 2015Year
Thr
ough
put (
Mbp
s)
Ethernet
1Base-T
10Base-T
100Base-T
1000Base-T
10GBase-T
USB
WPANUSB1.0
USB1.1
USB2.0
USB3.0
802.11
802.11b
802.11a
802.11n
802.11ac
WLAN
11ac is expected to cover from low data rate services to very high data rate services.
Further increase in the throughput might be expected.
May 11th, 2009
Slide 4
doc.:IEEE 802.11-09/0536r0
Submission
Proliferation of WLANs
APAPAP
APAP
AP
AP
APAP
AP
AP
AP
802.11ac AP
Large increase in the number of APs / STAs is expected.
May 11th, 2009
Slide 5
doc.:IEEE 802.11-09/0536r0
Submission5
80MHz mode
Over size MIMO
SDMA/OFDMA
Others
Number of available channels in 5GHz band
20MHz mode
40MHz mode
80MHz mode
Frequency band allocation in Japan
5470 5510 5550 5590 5630 5670 5725[MHz]
5150 5190 5230 5270 5310 5350[MHz]5250
5710
Only 4 channels can be used for 80MHz mode while 9 / 19 channels are available for 40 / 20 MHz mode.
May 11th, 2009
Slide 6
doc.:IEEE 802.11-09/0536r0
Submission
OBSS in 802.11ac
OBSS scenario is more likely to happen in 11ac compared to 11n due to limited . We think addressing OBSS issue in TGac is important because it
highly relates to the spatial domain control.
Example: Excessive NAV setting might affect throughput in the adjacent BSS.
AP1
STA11
AP2
STA21 STA22
Overlapped BSS
BSS1 BSS2
IEEE802.11acIEEE802.11a/n/ac
May 11th, 2009
Slide 7
doc.:IEEE 802.11-09/0536r0
Submission
Possible Simulation Scenario
• Example of Evaluation Conditions– Number of APs = 2
• Case 0: AP1:11n, AP2:11n• Case 1: AP1:11ac, AP2: 11n• Case 2: AP1: 11ac, AP2: 11ac
– Location of APs: T.B.D.– Location of STAs: T.B.D.– Traffic from AP to STAs: T.B.D.– Traffic from STAs to AP: T.B.D.– Channel model type applied : T.B.D.
• Possible Requirements– Case 1 and Case2:
• Throughput at each AP must be equal to or higher than that of case 0.
We think OBSS situation should be included in “Functional Requirements and Evaluation Methodology. ”
AP1
STA11
AP2
STA21 STA22
Overlapped BSS
BSS1 BSS2
IEEE802.11acIEEE802.11a/n/ac
May 11th, 2009
Slide 8
doc.:IEEE 802.11-09/0536r0
Submission
Conclusions
• Large number of APs / STAs is expected in 802.11ac.
• OBSS is more likely to happen in 802.11ac compared to 802.11n.
• We propose addressing for OBSS issue in TGac. We also suggest the following functional requirement.
“802.11ac shall maintain or increase throughput of each BSS in OBSS when some of 802.11a/n BSSs are replaced by 802.11ac BSSs.”