CC Pandora limits WIFI speed if lid closed

[dimag0g]

Hello,

I was transferring a big file from a CC Pandora to a GHz Pandora over WIFI. Since the transfer was taking much longer than expected, I decided to investigate the cause of the slowdown, and  was surprised to find that it was CC unit's lid which was affecting the transfer. Below are the plots I made with sysinfo.

CC Pandora (running thttpd server). Note that the speed drops from 200 KB/s to 35 KB/s when I close the lid.

GHz Pandora (running palemoon). Note that nothing happens when I open/close the lid.

Lid close setting on both units is to turn off screen. I attach complete logs for the reference.

Does anybody have an explanation on this, or experience a similar behavior?

 

[elw3]

Hm I wonder if the rebirth has the same phenomen, that would explain a lot here.

 

[Neelix]

What is your lid-close setting set to?

If you open the lid-close-settings dialogue, it tells you what the current setting is in the text at the top.

- Neelix

 

[comradekingu]

Is it when you trigger the event, or when you actually move the lid? The latter would maybe be an explanation in itself, since i think the antenna is in there.

 

[FBnil]

A cantenna (a portmanteau blending the words can and antenna) is a homemade directional waveguide antenna, made out of an open-ended metal can.

Cantennas are typically used to increase the range of (or discover) Wi-Fi networks.

http://en.wikipedia.org/wiki/Cantenna

Joking aside, can you put a small magnet on the right side, just where the magnet of the speaker would touch when the lid is closed. This will trigger the lid close scripts, while the lid is still open. That way, if the connection is slower, it is the software, not the position of the lid (hardware). My wifi router for example, blasts more one way, turn the apparatus around, and the signal strength drops.

 

[dimag0g]

What is your lid-close setting set to?

If you open the lid-close-settings dialogue, it tells you what the current setting is in the text at the top.

"Turn off screen" is the only option compatible with wifi at all, so it's active on both units.

Is it when you trigger the event, or when you actually move the lid? The latter would maybe be an explanation in itself, since i think the antenna is in there.

The speed drop is clearly related to the distance between the lid and the rest of the unit. When the distance is 3cm or more (~20-25 degrees angle) there is no noticeable effect. At about 2cm (~15 degrees angle) the speed drops from 200 KB/s to about 100 KB/s. The screen is still on at this point. Closing the lid completely drops the speed to 35-40 KB/s.

This happens regardless of the orientation (i.e. when the unit is on the table and the lid is moving or when the lid is on the table and the unit is moving).

Joking aside, can you put a small magnet on the right side, just where the magnet of the speaker would touch when the lid is closed. This will trigger the lid close scripts, while the lid is still open. That way, if the connection is slower, it is the software, not the position of the lid (hardware). My wifi router for example, blasts more one way, turn the apparatus around, and the signal strength drops.

Good advice! The magnet shuts down the screen (as expected) without affecting the connection speed.

 

[comradekingu]

Is that a broken Wi-Fi antenna cable on your part, or is it reproducible for others?

 

[FBnil]

Is that a broken Wi-Fi antenna cable on your part, or is it reproducible for others?

Good question. Anyone with a CC willing to do the test?

 

[dimag0g]

Is that a broken Wi-Fi antenna cable on your part, or is it reproducible for others?

Good question. Anyone with a CC willing to do the test?

Not sure if any of the CC units have the same issue, but it definitely comes from the antenna/cable. Connecting an external antenna cures it completely.