long distance usb1.1 link

[Telfo2002]

Hi,
I want to use a 4-wire unshielded and twisted cable of a indoor installation as a transmission system for a usb connection between a PC and several webcams across a house (25 to 40m away). My goal is only use 2 usb hubs (one in the connection to PC and other in a webcam).

I have read that according to standards, only 5m cable can be used in usb segments and no more than 5 hubs can be cascaded.

I have tested 12m utp cable (4-wires) with usb segments and it works with some devices (i.e. flash keys and several usb cameras) but others not . Also it only works on desktop PC.

Any suggestion for reaching such a long distance with usb and 4-wire?

Thanks on advance.

 

[djalli]

Telfo2002

Data MUST!!! drop in bandwidth speed as distance increases or as many hubs you use. Have you measured?

Shielding is protection from interferences.

Using unshielded you expose to interferences. Even your cell phone will interfere in data transmission as contribution to temperature of cable at least.

Unless you have some re-generative/amplification device it is not possible. Here is some example you are very fully aware: Fiber optics every 11km have amplifiers to amplify weak signal. Light in fiber optics is an Electromagnetic Wave in guided medium. So is the data in your USB.

Who knows, I dont maybe there are cables designed for low loss in market to make longer distances.

As far as I know it seems impossible.

 

[unlving]

use some amplifiers or something like 5 meters or so

 

[brmadhukar]

Hi,
This may not be the ideal thing for you to do but it works. Use four shielded RF cables and use with the USB connectors. Use low loss. It will help you.
B RM