WLAN Signalstärke messen

precxx

schläft auf dem Boardsofa
Servus,

Habe ein WLAN-Netzwerk im Haus und gehe mitm Läppi kabellos on.

Jetzt würd ich gern mal die Signalstärke an verschiedenen Stellen des Hauses messen.

Die XP-integrierte Abstufung mit 5 Balken ist ja wohl etwas "sehr" dürftig. Welche Tools können einem da denn genauere Auskunft geben?

thx
 
Ah jepp, danke, genau sowas habsch gesucht ;)

Ich tippe mal, Signal ist der negative Mbps Wert?

Oder könntest du mir die Bezeichnungen noch erklären?

  • SNR
  • Signal+
  • Noise-
  • SNR+
    [/list=a]

    thx
 
Habe mir das Programm jetzt auch mal besorgt - feini feini... aber ich hätte gerne auch noch ein wenig Erläuterung :angel
 
Na willkommen im Club!!! :D

Zumindest kann ich meine vorhergehende Vermutung mal ausschliessen, denn
"je höher der grüne Balken, desto stärker das Signal!"

Zumindest sackt der Balken im Erdgeschoss im Gegensatz zu mir hier im zweiten Stock etwas ab.

Neue Vermutung: 100 + angezeigter Peakwert = Signalstärke in Mbps

Also wär das bei mir, ca. 2 Meter vom WLAN-Router weg, ca. 68Mbps.

Könnte hinkommen... :)

Aber hat jemand mal ne genauere Erklärung der Symbole???
 
Naja... in der FAQ steht nix, aber hab im Forum was gefunden:

Question: What do the parameters in NetStumblers Detailed View mean?

Answer:

MAC - Media Address Controller Address - This is basically the hardcoded address of the Access Point. This is coded at the factory by the vendor and is usually unique for each AP (unless the address is spoofed)

SSID - Service Set Identifier - The name of the network that the clients use to identify which network they are communicating with. Some APs send out their SSID in Beacon Packets in order to let clients know how to communicate with them. A common security method for securing APs is to turn of the transmit of Beacon Packets.

Name - Not sure myself yet

Channel - The channel that the AP operates at. THere are 12 channels in the US and 14 international.

Vendor - The company that sells the AP.

Type - The type of device that NetStumbler detected. The two types that I have encountered so far are AP (Access Point - AP acts as a server and clients communicate with it directly) and PEER (Peer to Peer Network (ad-Hoc) - clients communicate among themselves. Usually somewhere on the network is a gateway to an in internal network). If anyone knows of any other types please post them.

Encryption - The type of encryption used on the network. So far I have only seen WEP (Wireless Encryption Protocol) which can only encrypt data packets while the other packets such as beaconing, probes, and joining are left unencrypted. This supposedly means that you can see packets that relate to the AP brodcasting its SSID and clients probing and joining the network, but all of the actual data packets (could be anything ie: HTTP, AIM, FTP) are encrypted. There are methods in which to brute force the WEP key as well as cracking the key through weak keys.

SNR - Signal to Noise Ratio - Higher is better and any positive number is decent.

Signal+ - The best Signal that NetStumbler has picked up on the current scan (higher is better).

Noise- - The least amount of Noise that NetStumbler has picked up on the current scan (lower is better).

SNR+ - The best Signal to Noise ratio that NetStumbler has picked up on the current scan (higher is better).

Latitude - Im assuming your current latitude based on a GPS device.

Longitude - Im assuming your current longitude based on a GPS device.

First Session - The time that you first recieved packets from the current AP.

Last Session - The last encounter that you had with the AP.

Signal - The current signal that you are recieving from the device. Higher is better. The strength on the signal can be influenced from a number of factors including strength of the cards probes, strength of the device, obstructions that might be in the way of your communication path, etc.

Noise - The current amount of noise that is being picked up by your card. Lower is better. Noise includes signals being picked up by devices other than APs that operate at the same frequency as 802.11b (2.4ghZ). These include cordless phones and other Wi-Fi devices.

Flags - (from official FAQ) The flag field contains the 802.11 capability information in hexadecimal. It's documented in section 7.3.1.4 of the 802.11b spec. To save you having to go and look, the bits are:
0001 ESS ("Infrastructure")
0002 IBSS ("Ad-Hoc")
0004 CF-Pollable
0008 CF-Poll Request
0010 Privacy ("WEP")
0020 Short Preamble
0040 PBCC
0080 Channel Agility
FF00 Reserved

Beacon Interval - I am assuming that this is the interval in milliseconds at which the device is sending beacon packets.

Any information that can be added to this is greatly appreciated




und:


Q: What is all this talk about dB and deciBels. I thought radio power is expressed in Watts?
Q: Why are deciBels expressed in negative numbers in NetStumbler?
Q: Why doesn't SNR equal Signal/Noise?

A: Decibels (or dB) is a REFERENCE value only. You have to reference it to a known value such as power in watts, milliwatts or voltage in volts, millivolts and microvolts. For power, dB
is expressed as:

dB = 10 * log10(p)

Now with that in mind:

Transmitters, such as those used in commercial microwave transmitters are referenced to 1 milliwatt. So

0 dBm = 10 log10(1 mW)

therefore a transmitter of 1 watt would be a +30 dbm transmitter, a 1/2 watt transmitter would be +27 dbm or a 0 dbm transmitter would be 1 milliwatt.

0 dbm= 1 milliwatt
10 dbm= 10 milliwatts
20 dbm= 100 milliwatts
30 dbm= 1000 milliwats or 1 watt

Received signal strength reads negative numbers because of the free space and path loss of the signal; a negative number simply means the power is less than 1mW. Thus, a negative dB value represents a loss, and a positive one represents a gain.

The noise floor is the signal strength of the background noise, which is caused by man made devices and nature, such as the sun.

Your signal to noise ratio (SNR) is how high your signal is above that noise floor. So if your noise floor is -92dB and your signal is -82dB, then your SNR is 10. Note that the SNR is obtained by subtracting the noise value from the signal instead of dividing because the signal and noise are expressed in dB. Thus:

SNR = S(mW)/N(mW) = S(dBm) - N(dBm)


:D

Und noch was feines (für mich selber)... hab mittels SSID, WEP, MAC usw mein Flag von 0001 auf 0011 hochgeschraubt :D :D :D
 
Jetzt bleibt nur noch eine Frage:

Mit dem Netstumbler kann ich mir ja die empfangene Radio-Leistung in Watt ausrechnen. db --> mW

Aber kann ich damit auch die Übertragungsrate in Mbps bestimmen?
 
Oben