One of the best wi-fi tools you have on your Windows based computer is netsh. Netsh can be used to find out information about wi-fi.
Open a command prompt and you can use these tools…
netsh wlan show networks
netsh wlan show networks mode=bssid
- Uses your current wireless card and connection software
– Works with Windows XP, Vista and 7 (32 and 64 bit)
– Compatible with most GPS devices
– Track the strength of received signals in dBm over time
– Sort by MAC address, SSID, Channel, RSSI, and Time
– Export Wi-Fi and GPS data to a KML file in Google Earth
Vistumbler (GPS Capable)
- Find Wireless access points
- GPS Support
- Export/Import access points from Vistumbler TXT/VS1/VSZ or Netstumbler TXT/Text NS1
- Export access point GPS locations to a google earth kml file or GPX(GPS eXchange format)
- Live Google Earth Tracking – Auto KML automatically shows access points in google earth.
- Speaks Signal Strength using sound files, windows sound api, or MIDI
- 6 graphical, diagnostic views:
*Timecourse of Beacon Qualities For Each Access Point
* Differential Display of Beacon Qualities for Each Access Point
* Usage of Each of the 802.11 Channels
* Timecourse of the Usage of Each of the Channels
* Heatmap / Waterfall Chart of the 802.11 Channels
* Channel Spectrogram of the 802.11 Channels. The more (and different) ways you have at looking at data then the greater the chance something will catch your eye that you might otherwise miss if only a single type of chart were used.
- Generates reports in Adobe PDF format
- Powerful and innovative logging and recording capability.NetSurveyor’s playback mode is unique in that it shows you all the recorded data
- Find Wi-Fi networks
- Managing and troubleshooting Wi-Fi connections
- Verifying Wi-Fi coverage
- Locating Wi-Fi devices
- Detecting rogue APs
What GPS have we used successfully and easily installs in Windows for the GPS Wi-Fi finders above? The Microsoft GPS Receiver. The receiver is small, light weight and installs easily.
Our class uses a scientific method of studying wireless and security. With hands-on during every term (not in a closed lab like a majority of higher-ed institutions), the classes we teach really enjoy the study of wireless and analyzing signals. During a recent study we found over 380 access points of which 50% were unsecure.
WiGLE has a global map drawn up by wardrivers. Viewing the maps is scary – really, really scary. These online GPS maps show secured and unsecured networks.
Attaching to unknown networks that are unsecured and not public is both dangerous and illegal. Actually connecting to wireless hotspots can be dangerous (See our article on attaching to HotSpots). You should always use a vpn when connecting to a hotspot. There are now applications that allow laptops, netbooks and droids to be setup as hotspots. With packet capturing software, your data can be intercepted if you don’t use a vpn.
Improving your wireless signal is actually is easy. For as little as $40, you can gain (from 30mw) to 1000mw or even 2000mw with the Alpha Antenna. With a standard laptop, we see approximately eight access points. With the Alpha we see approximately 14, and with a large antenna we were able to see 44 access points.
So what if you get a larger antenna? There is a balance of antenna type vs. antenna gain. A larger antenna can be better, if it is not too large.
Decibels in relation to power gain:
20 dB is an increase of 100X in power
10 dB is an increase of 10X in power
6 dB is an increase of 4X in power
3 dB is an increase of 2X in power
2 dB is an increase of 1.6X in power
1 dB is an increase of 1.25X in power
0 dB is no increase or decrease in power
Decibels/dB, how to understand their relationship to power loss:
1 dB loss: 80% of power remains.
2 dB loss: 63% of power remains.
3 dB loss: 50% of power remains.
6 dB loss: 25% of power remains.
9 dB loss: 12.5% of power remains.
10 dB loss: 10% of power remains.
12 dB loss: 6.25% of power remains.
20 dB loss: 1 percent of power remains.
(Therefore professional wireless cards have to be used for larger antennas)
If you add an antenna (yagi, omnidirectional) and need to add cable, make sure the total attenuation or loss is no more than about 3 db at 2.4 GHz or you could lose half of your total transmit power before it even reaches the antenna.
Specs on the Alfa Antenna ~
* Compatible with IEEE 802.11n, 802.11b/g/n wireless standards
* 2.4GHz frequency band, MIMO (Multiple Input Multiple Output)
* Complies with Universal Serial Bus Rev. 2.0 specifications
* High speed transfer TX data rate up to 150 Mbps
* Supports WPS by S/W
* Supports wireless data encryption with 64/128-bit WEP, WPA, WPA2, TKIP, AES
* Wide Range coverage
* Compliant with FCC Part 15.247 for US, ETS 300 328 for Europe
* Works with Windows 2000, XP 32/64, Vista 32/64, Windows 7 32/64.
- IEEE 802.11b/g/n standard
– USB 2.0 standard
– Up to 150Mbps for 802.11n connections
– Frequency Range: 2.412~2.483 GHz
– Receive sensitivity 11b: -92dBm, 11g: -76dBm, 11n: -73dBm@HT20, -70dBm@HT40
Want to further analyze signals? Use a Spectrum Analyzer ($40+).
If you are looking for an economical solution the 2.4 Ghz Spectrum Analyzer by Ubiquiti is an excellent buy and is around $40+ – with an external antenna (AirView software is free) My recent purchase for our class (personal purchase) is an excellent production and teaching tool.
A Spectrum Analyzer normally cost several hundred dollars. This solution is an excellent solution for viewing the distribution of RF energy in the 2.4GHz band. By viewing the analyzer, you can determine which channel has the least interference and select an appropriate channel for maximum performance.
You must purchase the hardware in order to use the software.
Excellent Product for the money.