More Related Content Similar to 20120407 hklug-os-workshop-5-wifi-mesh (20) 20120407 hklug-os-workshop-5-wifi-mesh1. Mesh networks
using commodity WiFi routers
and OpenWRT
Alexander List <alex@wurzel.at>
Open Source Workshop #5 (7 Apr 2012)
City University of Hong Kong
4. WiFi
IEEE 802.11
2.4 GHz ISM band (100 mW EIRP), ch. 1-14
60 MHz → 3 non-overlapping channels (1/6/11)
5 GHz ISM band (up to 1W EIRP)
Indoor channels (5.15 – 5.25 GHz, ch. 36-48)
Outdoor channels (5.25 – 5.6 GHz, ch. 52-140)
Always check national regulation (HK: OFCA)
6. 802.11 modes
Infrastructure mode (STA → AP)
Home network
Office
Café
Ad-hoc mode (STA-STA)
Mac OS “create network” (AirPort menu)
Linux: iwconfig wlan0 mode Ad-Hoc
Ubuntu: using Network Manager
9. China: TP-Link
TL-WR703N: 57x57x18mm, ~RMB 95
57x57x18mm
Atheros AR7420, 4MB flash, 32MB RAM
1x 10/100 Mbit/s Ethernet, USB 2.0, 802.11n
TL-WR743ND: ~200 HKD
Atheros AR7420, 4MB flash, 32MB RAM
5x 10/100 Mbit/s Ethernet, 802.11n
TL-WR1043ND: ~390 HKD
Atheros AR9132, 8MB flash, 5x GigE, 3xMIMO
14. Wireless community networks
Germany: Freifunk in several cities
Austria: FunkFeuer (120/200 nodes)
Athens: AWMN (2433 nodes)
Barcelona: guifi.net
Overview:
http://en.wikipedia.org/wiki/List_of_wireless_community_networks_by_region
20. Let's get this party started...
When:
Saturday, May 12, 2012, 14:00-17:00
Where:
DimSumLabs, 14/F, 100-102 Jervois Street,
Sheung Wan
Bring:
Laptop, WiFi router supporting OpenWRT