1. Advantages of multiple channel usage in 11s WLAN Mesh network
Month Year
doc.: IEEE yy/xxxxr0
March 2005
Advantages of multiple channel usage in 11s WLAN Mesh network
Date: 2005-Mar-17
Authors:
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Atsushi Fujiwara
John Doe, Some Company

2. Month Year
doc.: IEEE yy/xxxxr0
March 2005
Abstract
This presentation discusses advantages on usage of multiple channels and requirements of channel setting technology for 11s mesh network
Atsushi Fujiwara
John Doe, Some Company

3. Contents Goal of presentation Requirements
March 2005
Contents
Goal of presentation
Requirements
Scenario for Single WLAN interface model
Advantage on usage of Multiple channels
Required technology for Multi WLAN interface model
Suggestions for 11s amendment
Atsushi Fujiwara

4. March 2005
Goal of presentation
Auto channel setting for mesh network is an important technology for easy setup, reliable network creation and wireless network performance optimization
In this presentation, the requirement for channel setting technology which should be defined in 11s is clarified.
Atsushi Fujiwara

5. March 2005
Requirements
Simple Auto Channel Setting mechanism shall be defined to ensure the connectivity between Mesh nodes
Single WLAN interface case and Single channel
Framework to built the optimization technology for Multi WLAN Interface network must be defined
Channel Setting Algorithm itself shall be out of scope
Framework must be defined
Measurement in multi hop network
TPC/DFS in multi hop network
11h/k extension for WLAN mesh network
Atsushi Fujiwara

6. Channel unification mechanism
March 2005
Single WLAN Interface Case Requirement of channel setting in mesh network
Channel unification mechanism
shall be standardized
All MAPs shall use the same channel to establish mesh network even in such cases:
simultaneous power on
merge of multiple mesh network
Power on
Power on
scan
scan
Power on
Atsushi Fujiwara

7. Frameworks to support multiple WLAN interfaces shall be standardized
March 2005
Multi WLAN Interface Case Requirement of channel setting in mesh network
Frameworks to support multiple WLAN
interfaces shall be standardized
DFS, TPC, Measurement for mesh network
should be extension of 11k and 11h amendment for mesh network
Multiple channel usage will be solutions to some issues on mesh networks
Load balancing
QoS Support
Hidden / Exposed terminal problem
Atsushi Fujiwara

8. TCP Throughput degradation due to exposed terminal problem
Month Year
doc.: IEEE yy/xxxxr0
March 2005
TCP Throughput degradation due to exposed terminal problem
Case 1
Carrier
Sense
Range
End-to-end throughput
Case 2
TCP Throughput degradation due to
exposed terminal problem
The following principle is OUT OF SCOPE (of 11s)
This solution is available with 11h and 11k extensions.
Case 1
Case 2
Using different channel between the first and third hop recovers this degradation
How to select channel in more complicated case?
Atsushi Fujiwara
John Doe, Some Company

9. Usage of multiple channel for solving exposed terminal problem (1/7)
March 2005
Usage of multiple channel for solving exposed terminal problem (1/7)
Mesh network example by 6 nodes M1 M5 M3 M4 M2 M6
Atsushi Fujiwara

10. Usage of multiple channel for solving exposed terminal problem (2/7)
March 2005
Usage of multiple channel for solving exposed terminal problem (2/7)
While nodes 1 and 2 are communicating…
Conditions to avoid exposed
terminal problem M1 M5
L12 – L34
L12 – L45
L12 – L46 M3 M4 M2 M6
Atsushi Fujiwara

11. Usage of multiple channel for solving exposed terminal problem (3/7)
March 2005
Usage of multiple channel for solving exposed terminal problem (3/7)
While nodes 1 and 3 are communicating…
Conditions to avoid exposed
terminal problem M1 M5
L12 – L34
L12 – L45
L12 – L46
L13 – L26
L13 – L46
L13 – L56 M3 M4 M2 M6
Atsushi Fujiwara

12. Usage of multiple channel for solving exposed terminal problem (4/7)
March 2005
Usage of multiple channel for solving exposed terminal problem (4/7)
Derivation of chromatic graph
L12 – L34
L12 – L45
L12 – L46
L13 – L26
L13 – L46
L13 – L56
L23 – L15
L23 – L45
L23 – L56
L45 – L12
L45 – L23
L45 – L26
L46 – L12
L46 – L13
L46 – L15
L56 – L13
L56 – L23
L56 – L34
L26
L12
L34
L46
L45
L15
L13
L56
L23 M1 M5 M3 M4 M2 M6
Conditions to avoid exposed
terminal problem
Atsushi Fujiwara

13. Usage of multiple channel for solving exposed terminal problem (5/7)
March 2005
Usage of multiple channel for solving exposed terminal problem (5/7)
All possible patterns in 5-node mesh network (21 patterns)
Atsushi Fujiwara

14. Usage of multiple channel for solving exposed terminal problem (6/7)
March 2005
Usage of multiple channel for solving exposed terminal problem (6/7)
Number of required channels for all the possible topology (up to 8 nodes) 1 2 3 4 5 6 7 8 10 14 78
366
1599 24
468
8076
1421
total 21
112
853
11117
Nodes
Channels
Atsushi Fujiwara

15. Usage of multiple channel for solving exposed terminal problem (7/7)
Month Year
doc.: IEEE yy/xxxxr0
March 2005
Usage of multiple channel for solving exposed terminal problem (7/7)
Required number of channels for practical topology (up to 10 nodes)
電波の有効利用の観点で、必要最小限でのチャネル設定が重要ですよ
Atsushi Fujiwara
John Doe, Some Company

16. Suggestions for 11s amendment
March 2005
Suggestions for 11s amendment
11s shall standardize:
Auto Channel Setting mechanism to ensure the connectivity
Frameworks to support multiple WLAN interfaces
DFS, TPC, Measurement for mesh network
should be extension of 11k and 11h amendment for mesh network
Atsushi Fujiwara