1. IEEE 802.21 MEDIA INDEPENDENT HANDOVER DCN: 21-60-0000-01
Title: CMCC Wireless Mesh Trial Network Introduction
Date Submitted: March 10, 2010
Presented at IEEE session #37 in Orlando
Authors or Source(s):
Dapeng Liu (China Mobile)
Abstract: Brief introduction of CMCC’s trial wireless mesh network

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3. Contents Motivation and Background Mesh Trial Network and Experiment
How to Achieve Carrier Grade HWN
How HWN SG Could Help

4. Motivation and Background
Background of CMCC’s WiFi Mesh Trial Network
Increasing demand of high bandwidth service
In some scenario ,Wireless Mesh Network may provide higher bandwidth service with lower cost
Wireless City Projects initiated by local government
Wireless Mesh is considered as one of the promising technology in Wireless City Projects
Goals of CMCC’s WiFi Mesh Trial Network
Gain experience of wireless mesh network design & deployment
Test of wireless mesh network’s performance :
Performance/capacity/coverage test in urban scenario
Service provisioning capability test
To see whether wireless mesh network could satisfy our requirement

5. Usage Scenario of Wireless Mesh
Enterprise service
Large enterprise coverage
Campus Internet service
Lack of fixed line infrastructure scenario
Rural area
No sufficient fixed line infrastructure
Difficult to deploy fixed network scenario
Inter-buildings coverage
Home Internet access service
CMCC lacks of fixed line resources
Consider to use wireless to provide Internet access service for home users

6. Contents Motivation and Background Mesh Trial Network and Experiment
How to Achieve Carrier Grade HWN
How HWN SG Could Help

7. CMCC’s WiFi Mesh Trial Network
Location: Shanghai densely urban area
Complex wireless environment:
Tall buildings, elevated bridges  
High population density 
Complex wireless environment

8. Wireless Trial Network Topology
Node 2
Node 3
Node 1
Node 4
Node 5
Coverage of 2.4G Wi-Fi
To core network
Server a
b/g a
b/g a
b/g a
b/g a
b/g
5.8GHz(802.11a) uses as backhaul; 2.4G(802.11b/g) uses as wireless access

9. Experiment Items Mesh functionality experiment
Mesh node function experiment
Mesh gateway function
Mesh repeater function
Mesh edge node function
Mesh security
DHCP relay function
Mesh QoS
Mesh disaster tolerance experiment
Mesh topology discover
Auto configuration
Self-healing

10. Experiment Items (cont.)
Mesh network handover experiment
Intra-domain handover (Walking |30Km/h|60Km/h)
Inter-domain handover(Walking |30Km/h|60Km/h)
Mesh network performance experiment
Capacity experiment
1 hop configuration
2 hop configuration
3 hop configuration ….
Coverage experiment
Traffic vs distance
Latency experiment

11. Experiment Result Through output declines as hop increases Test Item
Mesh network throughput experiment result
Test Item
1st hop
2nd hop
3rd hop
4th hop
Total
AVR
MAX
1 hop mesh network throughput (Mbps)
Uplink
17.641
22.222 －
17.64
Downlink
18.016
22.857
18.02
2 hop mesh network throughput (Mbps)
9.844
19.512
7.518
10.667
17.36
9.985
23.530
9.191
18.605
19.18
3 hop mesh network throughput (Mbps)
7.186
15.385
5.662
8.696
4.338
6.154
17.19
7.461
16.327
7.044
11.594
4.619
6.612
19.12
4 hop mesh network throughput (Mbps)
5.974
13.333
4.874
10.811
3.489
5.128
3.189
4.571
17.53
6.935
14.815
6.608
10.39
4.209
6.957
1.007
1.424
18.76
Through output declines as hop increases

12. Experiment Result (cont.)
Mesh network latency experiment Result
Experiment item
Service
Ave. Delay (ms)
Packet lost rate
Single AP latency
No FTP load 9
FTP 2M
200 2%
FTP no speed limit
117 3%
1 hop latency 10 8 12
2 hop latency
119
3 hop latency 13 0%
FTP 5M 4%
FTP no speed limit 11
18%
4 hop latency 14 5% 16 7%
Latency may not be a significant issue

13. Conclusions Mesh network basic design principles
Tradeoff between coverage/throughput/interference
Optimize investment
Multi-hop design principle
Backup link for robustness
Tradeoff between coverage and throughput
Hops vs throughput
Experience result
Limit hops to increase performance

14. Experience and Conclusions (cont.)
Frequency configuration optimization
2.4GHz for access service; 5.8GHz for backhaul to reduce interference
Using power control to reduce interference
Using directional antenna
Better coverage
Less interference

15. Experience and Conclusions (cont.)
Different deployment strategy in different scenarios
Rural area scenario
Optical fiber access can only reach to major towns
Very limited fixed line access resources in some villages
Wireless mesh is a very promising solution in this scenario
Several villages could be connected together to form a mesh network
Only few mesh nodes need to have backhaul resources
May use microwave as backhaul to form a heterogeneous mesh network

16. Experience and Conclusions (cont.)
Urban area scenario
Need 8 mesh devices to coverage 1 sq.km. in ordinary urban area
fiber
fiber
Wireless city scenario
Many local governments initiate wireless city project s using mesh

17. Experience and Conclusions (cont.)
Home Internet access service
CMCC is lack of fixed line resources in residential areas
Outdoor heterogeneous mesh node
with and microwave as backhaul
Indoor mesh node with
Indoor mesh node with
Would be a promising approach for the operators that lack of fixed line resources and want to provide home user Internet access service
Could also be used as an option for HNB backhaul

18. Contents Motivation and Background Mesh Trial Network and Experiment
How to Achieve Carrier Grade HWN
How HWN SG Could Help

19. Outlook: How to Achieve Carrier Grade Heterogeneous Mesh Network
Management
Performance monitoring
Fault detection and report
Topology discover and management
Configuration
Auto configuration
Self healing
QoS
Network controlled QoS enabled service provision

20. Contents Motivation and Background Mesh Trial Network and Experiment
How to Achieve Carrier Grade HWN
How HWN SG Could Help

21. How HWN SG could Help
extension may be helpful to improve heterogeneous wireless mesh network’s quality and usability
Potential areas that we could work on:
Heterogeneous Mesh network configuration
Fault detection and report
Performance monitoring
…..

22. Thanks
Q&A