[vdr] Re: OT: WLAN

[Christian Berger <einStein@donau.de>]

René Bartsch schrieb:
> 
> ----- Original Message -----
> From: "Christian Berger" <einStein@donau.de>
> To: <vdr@linuxtv.org>
> Sent: Friday, May 10, 2002 12:36 PM
> Subject: [vdr] Re: OT: WLAN
> 
> > Steffen Koch schrieb:
> > >
> > > On Fri, 10 May 2002 10:19:20 +0200, Emil Naepflein wrote:
> > >
> > > >> >WLAN is certainly to slow for a time critical stream with 500 KB/s.
> You
> > > >> >will be happy to reach the 500 KB with normal data transfer. Just
> have
> > > >> >look at the tests that were published in several magazines.
> > > >> I've a tekram WLAN AP and two tekram WLAN PCI-cards. They work fine
> and
> > > >> I get ftp download from my vdr machine with approx 800 KB/s...
> > > >I use Lucent Cards with a ELSA AP and get about 500 KB/s with WEP
> > > >enabled.
> > > >Are you using WEP?
> > > no. I can't. The connection breaks after a few seconds with WEP
> > > enabled... Now I use access control via MAC-address...
> >
> >
> > Ever thought about using 2 wireless networks with 2 cards on different
> > frequencies. With proper filtering in front of the cards it might work
> > quite well. Then we would not only have more rubust transmission, but
> > also about twice the bandwidth.
> >
> > Servus
> >   Casandro
> >
> 
> Linux-kernel supports bonding. That means two or more physical NICs can be
> used as one logical NIC with one IP.
> 
> Rene

Well the problems here actually are on the physical level. The recievers
inside those cards are rather cheap. So if you have 2 cards on 2
different channels next to eachother they _might_ disturb eachother.
This doesn't have to happen, but it might.


> > Here: 1st Wave WaveMaxx AP + WaveMaxx Card. Highest rate ~ 500KB/sec.
> > That's under optimal circumstances, but if you don't have good receipt
> > the transfer rate drop to less than 100KB/sec (worst case).
> >
> > ...Andreas
> >
> 
> The more the distance or hinderance the lower the receiving-level will be.
> This causes a higher failure-rate and the data-rate goes down.

Well actually that will cause droped packets. In our situation we might
try to lower the "datarate" setting to, let's say 5MBit/sec. Chances are
it will work better than 11Mbit.
 
> If you have trouble with data-rate you can use external antennas which raise
> the range up to three times.

Uhm, with a good antenna you can raise the range up to whatever you
want. I think a factor of 100 is realistic with good antennas, however
you loose area direction wise.
 
> Rene

Servus
  Casandro
 


Servus
  Casandro