# how to check i am fully using 802.11 g router [solved]

## h2sammo

i have a 9 dB antenna hooked up to my wireless card on my desktop. it is located on the other side of the house and i am getting horrible connection, i dont know how to check signal strength but rates of transfer rarely go above 100 KiB/s on a Comcast network.

how do i check i have the kernel properly configure to use the range of the router (Motorola SBG900) effectively and maybe that i am using full bandwidth supported. i would like your help on this before i buy a 802.11 n router. Maybe that will give better range.

```

02:07.0 Network controller: Broadcom Corporation BCM4306 802.11b/g Wireless LAN Controller (rev 03)

   Subsystem: Belkin Belkin F5D7001 High-Speed Mode Wireless G Network Card

   Kernel driver in use: b43-pci-bridge

   Kernel modules: ssb

```

Last edited by h2sammo on Mon May 17, 2010 12:39 pm; edited 1 time in total

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## NeddySeagoon

h2sammo,

Run 

```
iwconfig wlan0
```

and post the output.

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## h2sammo

```
main Downloads # iwconfig wlan0

wlan0     IEEE 802.11bg  ESSID:"Motorola"  

          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:21:00:6D:E5:0F   

          Bit Rate:54 Mb/s   Tx-Power=20 dBm   

          Retry  long limit:7   RTS thr:off   Fragment thr:off

          Encryption key:off

          Power Management:off

          Link Quality=46/70  Signal level=-64 dBm  Noise level=-60 dBm

          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0

          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
```

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## NeddySeagoon

h2sammo,

```
Bit Rate:54 Mb/s   Tx-Power=20 dBm 
```

shows the link speed is 54Mbit/sec, whic is as good as it gets

Your Tx-Power is less than half of the permitted UK max of 27dBm.

You may be alble to turn that up. Read 

```
man iwconfig 
```

A Higher tx power can only have an indirect affect on your data rate as the link speed will not get faster but the error rate (if any) will reduce.

```
Link Quality=46/70  Signal level=-64 dBm  Noise level=-60 dBm 
```

Your signal to noise ratio appears to be -4db, which I don't believe. That means the signal is lost in the noise.

The noise level is normally around -90dBm.  Do you have something else in the house or nearby, sharing the 2.4G band, e.g. DECT cordless phones.

Try another channel and see if your noise level goes down.

Despite the unbelivabley bad signal to noise ratio the Link Quality is still 46/70 which is pretty good.

Try increasing your[/code] TX Power and try other channels.

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## h2sammo

no cordless phones, just other wifi devices (netbooks).

i am thinking the surge protector with 7 plugs (all filled) is right next to the antenna, the monitor is next to the antenna as well. maybe the magnetic fields generated by the electric fields existent on those wires generate the noise levels?

also, a technical clarification, isnt the S/N ratio calculated by dividing the signal by the noise?

EDIT: bit rate drops randomly:

```
wlan0     IEEE 802.11bg  ESSID:"Motorola"  

          Mode:Managed  Frequency:2.412 GHz  Access Point: 00:21:00:6D:E5:0F   

          Bit Rate:18 Mb/s   Tx-Power=20 dBm   

          Retry  long limit:7   RTS thr:off   Fragment thr:off

          Encryption key:off

          Power Management:off

          Link Quality=44/70  Signal level=-66 dBm  Noise level=-62 dBm

          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0

          Tx excessive retries:0  Invalid misc:0   Missed beacon:0
```

but annoyingly often.

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## h2sammo

i changed to channel 11 from the router interface and changed the mode from "b/g..." to "b/g enhanced". S/N ratio is higher now in the back of the house and more consistent.

thank you

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