Make a speed fallback on a WIFI Card

[sigmaX]

Dear Friends,

I got a wifi card ... which I noticed keeps its connection at 11 mbps ... even as I walk away ! so it doesn´t falls back into more distance tolerant speeds (this wifi card, an Ambicom, came  with a data table which indicated a convenient distance incresase for each mbps stepdown it made)...

The question is: Is the mbps fallback handled by the WIFI system (hardware / firmware) or by the OS DRIVERS ?

I would LOVE to manually set up  my wifi speed then ! .... I could set it up to 3mpbs or similar and gain several meters of connection availabilty

Any idea  ? help !

Regards,

Enrique.

[oreo]

There is no auto-fallback support in the drivers.

This guide below from Microsoft may help. These improvements can directly affect wireless range.

Achieving the Best Wireless Performance

The range and performance of any device on a wireless network is greatly affected by the environment in which it is used. For the best wireless coverage, consider where you place the base station, gateway, or router; where you place the adapters; and how you adjust the antennas. Some recommendations are:

Position the base station in line of sight to the wireless adapters for best performance.


• Position the base station, gateway, or router in a central location within the area to be used for wireless communications.
• Keep the wireless equipment away from large metallic objects, such as computer cases, display monitors, and appliances.
• Position the wireless equipment away from other electromagnetic devices, such as televisions, radios, cordless telephones, and microwave ovens.
• Position the wireless equipment so that large masonry structures, such as fireplaces, are not obstructing the radio path.
• Try to position the base station, gateway, or router in a place that is higher than computers and related equipment, for example, on a bookshelf.
• Adjust the antennas on the base station, gateway, or router and on the adapters to obtain the best radio signal strength.

Rotate the base station, gateway, or router to obtain the highest data throughput.

• Be aware that building construction, such as metal framing, ultraviolet-resistant window film, metallic paint, concrete or masonry walls, or multiple floors and walls reduce radio signal strength.
• Position the base station, gateway, or router away from other radio equipment that operates at a frequency of 2.4 gigahertz (GHz), such as microwave ovens and cordless telephones, which can affect the performance of Wi-Fi equipment.
• Be aware that wireless signal speed and range can be affected by interference from neighboring wireless networks and devices.
• You may need to change to a different wireless channel to improve performance.

[sigmaX]

But then, there must be a way to put the drivers on default in low speed  ?

[oreo]

But then, there must be a way to put the drivers on default in low speed  ?

There are some generic files that may control connection speed. Look in /home/etc/pcmcia. If you modify these system files, be careful and first make a backup.

Code: [Select]

# pwd

/home/etc/pcmcia

# grep RATE *

grep: cis: Is a directory

wireless:    if [ "$RATE" ]; then

wireless:       $IWPATH/iwconfig $DEVICE rate $RATE

wireless.opts:    RATE="auto"

wireless.opts:    RATE="auto"

wireless.opts:    RATE=""

wlan-ng:                for i in $BASICRATES; do

wlan-ng:                for i in $OPRATES; do

wlan-ng.opts:   BASICRATES="2 4"                # Rates for mgmt&ctl frames (in 500Kb/s)

wlan-ng.opts:   OPRATES="2 4 11 22"             # Supported rates in BSS (in 500Kb/s)

wlng2wt.opts:RATE=""

[zbones]

I know this code exists, but has anybody actually managed to default to a lower speed?

I keep meaning to have a go at fixing the speed, but never seem to find the time.

I will be getting my 760 tomorrow so it will probably be a while before I have settled on a rom and can find time to have a go.

Peter

[Anonymous]

Here is a script I tried in the past with OZ (I don\'t know if it will work on Sharp based ROMs).  It does stop and start the card, but did not seem to change the actual speed, or more importantly the range:

Code: [Select]

#!/bin/sh



/sbin/ifconfig wlan0 down

/sbin/iwconfig wlan0 key 65:c5:d3:45:e9

/sbin/iwconfig wlan0 rate 2M

/sbin/udhcpc -i wlan0

Basically:
- Bring down the interface
- Configure the WEP key (if you don\'t have one, I think you should be able to remove that line)
- Configure the speed (1, 2, 5.5, 11)
- Restart card with DHCP enabled (I\'m not 100% on exactly what this line did, but the card does restart at this point)

I then get the following when I type \"iwconfig\" at the command prompt:

Code: [Select]

wlan0     IEEE 802.11b  ESSID:"linksys"  Nickname:"openzaurus"

Mode:Managed  Frequency:2.437GHz  Access Point: 05:04:23:7A:4F:2F

Bit Rate=2Mb/s   Tx-Power:-9 dBm   Sensitivity=1/3  

Retry min limit:8   RTS thr:off   Fragment thr:off

Encryption key:65c5-d345-e9   Encryption mode:restricted

Power Management:off

Link Quality:92/92  Signal level:-44 dBm  Noise level:-93 dBm

Rx invalid nwid:0  invalid crypt:0  invalid misc:10879

It shows the change to 2Mb, but I don\'t see any range gain what so ever with the Z in use over 11Mb.  Maybe the driver is only capable of 11Mb, so the setting is ignored.  I did not do a bandwidth test, so someone may want to try that to see if there is any change there before digging deeper with this code.

[nitup]

Keep in mind, this only works for ROMs other than Sharp, Sharp didn\'t include wireless extensions into their kernel.

[zbones]

This would probably explain why I don\'t have a program called udhcpc and iwconfig just returns \"no wirless extensions\".

It looks like javaboy is compiling a kernel with wireless extensions for the prism2 cards.

I should be able to test if it has dropped the speed when the kernel is out as my ap can be configured to only work at certain speeds.

Peter