ALFA Network - AWUSO35H

ALFA Network - AWUSO35H is:
- USB external WI-FI / WLAN device
- Supporting 802.11 b/g
- Supporting WPA , WPA2 , WEP
- Supporting external antenna with RP-SMA connector
- I have tested to run this device with MS Windows, Slackware, CentOS without bigger issues.

lsusb: Will provide the in information about connected devices to USB interfaces

# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 002: ID 0bda:8187 Realtek Semiconductor Corp. RTL8187 Wireless Adapter           # Device has been detected with OS

ip: will provide i nformation about known network interfaces:

# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:27:0e:0e:b8:03 brd ff:ff:ff:ff:ff:ff
    inet 10.0.12.13/24 brd 10.0.12.255 scope global eth0
    inet6 fe80::227:eff:fe0e:b803/64 scope link
       valid_lft forever preferred_lft forever
3: wlan0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 1000                       # In our cause we do have interface wlan0
    link/ether 00:c0:ca:3e:f0:78 brd ff:ff:ff:ff:ff:ff

iwconfig: Will provide information about WI-FI / WLAN specific setting of interfaces:

# iwconfig
lo        no wireless extensions.

eth0      no wireless extensions.

wlan0     IEEE 802.11bg  ESSID:off/any                                                          # This is our WLAN interface
          Mode:Managed  Access Point: Not-Associated   Tx-Power=0 dBm
          Retry  long limit:7   RTS thr:off   Fragment thr:off
          Encryption key:off
          Power Management:on

Many countries do not have same standards but they flow local standards. As an example it is possible to see it in cause of power supply cables. In the cause that you will buy a power supply cable in UK it will be not compatible in EU as well it will not be compatible in USA or in Japan. It is really similar WI-FI / WLAN standard. In general the way how it is working (802.11 b/g) is same but in each country you can have differences.
Like:
- Channels that you can use
- Power for transmission that you can use
- …

For causes like this Linux is providing a way how to simplify your life. It is called CRDA (Central Regulatory Domain Agent) is the udev helper used to communicate between user space and the kernel, and it enables you to view and alter the wireless regulatory domain your kernel uses
See the current setting:

# iw reg get
country 00: DFS-UNSET                                                     # The configuretion is set to 00
        (2402 - 2472 @ 40), (3, 20)
        (2457 - 2482 @ 20), (3, 20), PASSIVE-SCAN, NO-IBSS
        (2474 - 2494 @ 20), (3, 20), NO-OFDM, PASSIVE-SCAN, NO-IBSS
        (5170 - 5250 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS
        (5735 - 5835 @ 40), (3, 20), PASSIVE-SCAN, NO-IBSS

#iw reg set --ISO_3166-1_alpha-2_country_code--

Updating configuration:

# iw reg set BO                             # In our cause we will use settings for Bolivia

# iwconfig wlan0 txpower 1000mW                         # Set power
# iwlist wlan0 txpower                                  # Check the power

http://wireless.kernel.org/en/developers/Regulatory # Linux wireless regulatory documentation
http://wireless.kernel.org/en/users/Documentation/iw # Linux Kernel documentation for “iw”
http://fitzcarraldoblog.wordpress.com/2013/01/20/setting-the-wireless-regulatory-domain-in-linux-on-your-laptop/ # Nice How To