In this exercise you will use a Mikrotik router to understand how a reflector can increase the gain of a standard monopole antenna.
We'll use a serial console to attach to the Mikrotik, so you'll need a USB port and a serial to USB adapter. We'll supply the adapter for this lab.
Windows users will need the Terminal Emulator called PuTTY, available here: http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
Linux users will need Minicom: apt-get install minicom or yum install minicom
Connect the adapter cable to a free USB port on your laptop.
Open the "Device Manager" application in Windows. In the "Ports" section you should see the new device. It will be appear as a "USB Serial Port" and should be assinged to a COM port, such as COM4.
Now launch PuTTY. Choose the connection type of Serial. Set the COM port to the one you found in device manager, and the speed to 115200, then click "Open".
Press enter once or twice and you should see a login prompt.
From a terminal, type:
ls -ltr /dev/*usb*This will help you find the USB serial device you just added. Then start "screen" using the device you just found:
screen /dev/tty.usbserial-DEVICENAME 115200Press enter once or twice and you should see a login prompt.
From a terminal, type:
dmesg |grep ttyYou should see your device at the end of the list. It might look like this:
[ 2843.525905] usb 2-2.2: FTDI USB Serial Device converter now attached to ttyUSB0In this case, your device will be identified by /dev/ttyUSB0. Now launch minicom with:
sudo minicom -sChoose the correct device, and set your line speed to 115200. Save this configuration as default "def", then "Exit" from the configuration screen and you will have a connection to the router. Press enter once or twice and you should see a login prompt.
The next time you run minicom, you can skip the -s and you will be taken straight to the current configuration
When you first connect, you should see this on the screen:
MikroTik 6.32.3
MikroTik Login: Log in with the username "admin" and no password. You should see this:
MMMM MMMM KKK TTTTTTTTTTT KKK
MMM MMMM MMM III KKK KKK RRRRRR OOOOOO TTT III KKK KKK
MMM MM MMM III KKKKK RRR RRR OOO OOO TTT III KKKKK
MMM MMM III KKK KKK RRRRRR OOO OOO TTT III KKK KKK
MMM MMM III KKK KKK RRR RRR OOOOOO TTT III KKK KKK
MikroTik RouterOS 6.32.3 (c) 1999-2015 http://www.mikrotik.com/
[?] Gives the list of available commands
command [?] Gives help on the command and list of arguments
[Tab] Completes the command/word. If the input is ambiguous,
a second [Tab] gives possible options
/ Move up to base level
.. Move up one level
/command Use command at the base level
[admin@MikroTik] >Note the instructions for navigating the Mikrotik command line above - in particular the idea of moving up and down levels, the "?" sign, and tab completion. For a detailed guide on Mikrotik's console, have a look at their wiki: http://wiki.mikrotik.com/wiki/Manual:Console. For this exercise, all the commands you need to know will be shown below.
Now view all of the Mikrotik's interfaces:
/interface printIn this lab, you should see several ethernet interfaces and a wireless interface.
[admin@MikroTik] > interface print
Flags: D - dynamic, X - disabled, R - running, S - slave
# NAME TYPE ACTUAL-MTU L2MTU MAX-L2MTU MAC-ADDRESS
0 R ether1 ether 1500 1600 00:0C:42:04:B8:80
1 ether2 ether 1500 1600 00:0C:42:04:B8:81
2 ether3 ether 1500 1600 00:0C:42:04:B8:82
3 X wlan1 wlan 1500 1600 00:0C:42:05:35:6E
[admin@MikroTik] > If your an interface has an "X" next to it, it's currently disabled. To enable the wireless interface, if it's disabled, type:
[admin@MikroTik] > /interface wireless set wlan1 disabled=noNow we'll set up that wireless interface to scan for Wi-Fi networks in the 2.4GHz frequency band, and we'll start a scan
[admin@MikroTik] > /interface wireless set wlan1 frequency=2412 band=2ghz-b/g scan-list=default
[admin@MikroTik] > interface wireless scan wlan1 We should see a whole lot of access points!
[admin@MikroTik] > interface wireless scan wlan1
Flags: A - active, P - privacy, R - routeros-network, N - nstreme, T - tdma, W - wds, B - bridge
ADDRESS SSID CHANNEL SIG NF SNR RADIO-NAME
AP 00:23:69:16:85:D9 DAMAGERUP 2412/20/gn -80 -94 14
APR B D4:CA:6D:A5:D4:0D tc2-aust-27b 2412/20-Ce/gn -82 -94 12 D4CA6DA5D40D
AP 94:4A:0C:F8:A2:1E vodafoneJSCK 2412/20/gn -85 -94 9
AP C4:71:30:43:9D:E5 Gramofon_439de4 2412/20/gn -90 -94 4
A R 00:0C:42:FC:52:0B Vistagate 2412/20-Ce/gn -89 -94 5 000C42FC520B
AP 00:0E:8F:A2:BA:7C radio 2412/20/gn -91 -94 3
AP 20:08:ED:02:65:64 vodafone655B 2422/20/gn -91 -93 2
AP C4:07:2F:6E:05:E6 SPARK-7MHLFZ 2422/20/gn -89 -93 4
AP 80:71:7A:7D:1A:4C SPARK-DNVXJL 2427/20/gn -95 -95 0
AP BC:96:80:2F:47:B4 Johnny 2437/20/gn -87 -95 8
P C0:8A:DE:20:53:68 2437/20/gn -91 -95 4
AP C0:8A:DE:23:D8:78 WCWifiSmart 2437/20/gn -89 -95 6
A C0:8A:DE:E3:D8:78 WCPD 2437/20/gn -91 -95 4
AP C0:8A:DE:23:D8:79 WCBYOD 2437/20/gn -89 -95 6
AP C0:8A:DE:63:D8:79 wl 2437/20/gn -88 -95 7
AP C0:8A:DE:A3:D8:79 WCStaff 2437/20/gn -89 -95 6
AP 78:A0:51:0E:3A:59 XFiles 2437/20-Ce/gn -89 -95 6
AP C0:FF:D4:9E:3D:09 Mimir-2.4 2442/20/gn -94 -93 -1
P 58:98:35:18:09:F7 KB 2447/20/gn -94 -94 0
AP 24:C9:A1:B3:FB:38 eduroam 2452/20/gn -84 -94 10
A 24:C9:A1:33:FB:38 CityLink WiFi 2452/20/gn -85 -94 9In the scan results, we can see the mode of the access point, whether it's acive, if there's privacy (encryption), what the access point's MAC address is, it's SSID, what channel it's on, and details on the amount of signal and noise received. Those last details are the most important for our lab.
If you want to cut down the bands scanned, you can specify this in your wireless lan setup. Here's wll limit the scan to channel 1:
[admin@MikroTik] > interface wireless set wlan1 scan-list=2412
[admin@MikroTik] > interface wireless scan wlan1 Now we only see networks on channel 1! The instructor will specify a channel to scan in the workshop, and an SSID in particular to note. Record the signal and noise of all the SSIDs you can see in a note on your computer, or just take a screen shot of the scan results!
We'll distribute scissors, tape, aluminium foil, and antenna templates to all participants. Assemble the antenna and fit it to your Mikrotik's antenna. Run your scan again and see how it's different.
[admin@MikroTik] > interface wireless scan wlan1 The best performing antenna (lowest signal level) to the target SSID will win a prize.
To replicate this antenna at home, visit Michael Erskine's Free Antennas website: http://www.freeantennas.com/