doc.: IEEE 802.11-13/1489r0

Submission

Nov 2013

Airport Capacity Analysis

Date: 2013-11

Authors:

Name Company Address Phone email Graham Smith DSP Group 1037 Suncast

Lane, Ste 112, El Dorado Hills, CA95762

916 358 8725 Graham.smith@dspg.com

Graham

Smith, DSP

Group

Slide 1

doc.: IEEE 802.11-13/1489r0

Submission

Background• 13/1012r4 Described Dynamic Sensitivity Control DSC and provided a

throughput calculation for a hypothetical Cell Structure network. – 3005Mbps vs. 397Mbps

• This presentation looks at the Apartment Complex Use Case and provides an estimate of the improvement in Capacity/Throughput when using Channel Selection and DSC

Nov 2013

Graham

Smith, DSP

Group

Slide 2

doc.: IEEE 802.11-13/1489r0

Submission

July 2013

1b Airport/train stations - public access and cellular offload

Pre-ConditionsHigh density users access internet through multiple operators’ WLAN network. The venue owner possibly manages or controls multiple operators’ WLAN networks uniformly for the purpose of users’ QoS.

Environment The environment is very complex and may suffer severe interference.

Each AP serves 120 devices in a 200m2 area. The inter-AP distance is in the range of 15~20m. Single/multiple operators.

ApplicationsVideo based applications: TV, VOD, Video conference; VHD highly compressed (100 Mbps): 50% of users

VPN applications (20 Mbps): 10% of users

Game online; 100 Mbps, < 100 ms jitter; < 100 ms latency: 10% of users

Internet access: email, twitter, web surf, IM. (20 Mbps): 30% of users

Traffic ConditionsInterference between APs belonging to the same managed ESS due to very high density deployment.

Interference between APs belonging to different managed ESS due to the presence of multiple operators.

Interference with unmanaged networks (P2P)

Interference with cellular (e.g. TD-LTE) in in-device coexistence scenario (e.g. User equipments running Wi-Fi and TD-LTE at the same time.)

Use CaseTravelers are using the network to surf websites, watch movies, play online games and access cloud services.

Slide 3 Laurent Cariou (Orange)

doc.: IEEE 802.11-13/1489r0

Submission

Channels

Nov 2013

Graham

Smith, DSP

Group

Slide 4

140

136

132

128

124

120

116

112

108

104

100

165

161

157

153

149

6460565248444036IEEE channel #

20 MHz

40 MHz

80 MHz

5170MHz

5330MHz

5490MHz

5710MHz

5735MHz

5835MHz

160 MHz

144

USA Eu Japan China Korea25 20MHz Channels 21 19 23 13 2112 40MHz Channels 10 9 10 6 10 6 80MHz Channels 4 4 5 3 5 2 160MHz Channels 1 2 2 1 2

Ref:Wikipedia

doc.: IEEE 802.11-13/1489r0

Submission

Denver Airport Terminal B

Nov 2013

Graham

Smith, DSP

Group

Slide 5

1040m

Restaurants/Food Court8 Gates 6 Gates 6 Gates 6 Gates 6 Gates 8 Gates

126m 126m 120m

115m

100m

doc.: IEEE 802.11-13/1489r0

Submission

How many people at the gates?

Nov 2013

Graham

Smith, DSP

Group

Slide 6

Airbus 380 seats 580 in 3 classes (can seat 853 in one class)

doc.: IEEE 802.11-13/1489r0

Submission

• Number of Gates = 40• Ave Passengers per Gate = 200• Percentage gates in use. peak = 60%• Total = 4800 passengers in Terminal • Assume 60% waiting at Gates, 40% in eating areas

Numbers

Nov 2013

Graham

Smith, DSP

Group

Slide 7

1040m

40m576 432 432 434 434 576

126m 126m 120m

115m

960 240 240240240

45m

USERS

doc.: IEEE 802.11-13/1489r0

Submission

• From “Use Case 1b”, for 120 users per AP– 50% using 100Mbps (VHD) = 100/60 = 1.67Mbps per user– 10% using 20Mbps (VPN) = 20/12 = 1.67Mbps per user– 10% using 100Mbps (Gaming) = 100/12 = 8.34Mbps per user– 30% using 20Mbps (Internet)= 20/36 = 0.56Mbps per user

• Total traffic for 120 users = 240Mbps• For 4800 users about 40 APs required (42 in example)

Capacity Requirement

Nov 2013

Graham

Smith, DSP

Group

Slide 8

1040m

40m5 4 4 4 4 5

126m 126m 120m115m

8 2 222

45m

APs

doc.: IEEE 802.11-13/1489r0

Submission

• Requirement is 240Mbps– 170Mbps Downlink– 70Mbps Uplink

• With EDCA Overhead say 480Mbps required – 340Mbps Downlink– 140Mbps Uplink

• PHY Rates (40MHz BW) – Downlink 8SS, 64 QAM ¾ , Short GI = 1080Mbps PHY

Throughput ~596Mbps– Uplink 2SS, 64 QAM ¾, Short GI = 270Mbps PHY

Throughput ~205Mbps

IS 10 Channels OK?

What is Practical PHY Rate and Throughput?

Nov 2013

Graham

Smith, DSP

Group

Slide 9

doc.: IEEE 802.11-13/1489r0

Submission

• 40 MHz BW 64QAM ¾– Typical RX sensitivity is -70dBm– Allow 5dB margin, use -65dBm

• TX power 18dBm • Assume 0dBi gain antennas

o +2dBi at AP, -2dBi at STA

• Range 150m Free Space (LOS), 40m indoor model• APs mounted high would tend to LOS but with obstruction losses

(e.g. people and antenna directivity), say10dB, the LOS is 60m.• Assume 40 – 60m range

RF Considerations

Nov 2013

Graham

Smith, DSP

Group

Slide 10

doc.: IEEE 802.11-13/1489r0

Submission

AP Layout

Nov 2013

Graham

Smith, DSP

Group

Slide 11

5 4 4 4 4 5

126m 126m 120m115m

8 2 222

45m

Regular spacing of APs fits the requirement10 Channels gives 200m between APs, no overlap

doc.: IEEE 802.11-13/1489r0

Submission

Get Out Statement – “I am not an expert at layouts for enterprise or hotspots (I have never done it) so my example analysis may have flaws.”

BUT on the face of it • 11ac APs with 40MHz BW will provide enough capacity

and coverage to meet this particular case example.

• What’s missing?– Need for fast handoff between APs for Mobile Users.

• Is 11r, OKC, or 11ai sufficient? • Can 11ai be improved for ‘handoff’ rather than initial link?

–

Points

Nov 2013

Graham

Smith, DSP

Group

Slide 12