wireless, i dont understand

[unruelysock]

i am just playing around with gnpvr. but i don't understand why i can log in to my server and read an mpeg over wireless fine no problims at all. but if i use gvpvr to stream an mpeg to me it will play and stall and play and stall.

if i look at the bit rate it is never more then 25% of the bandwidth on the wireless cad. and on the server it is not even 6% and at that time i thank that it was streaming to two computers.

i just was wondering. it is my curiosity

i guess this in not relay a support question, rather just trying to learn things.

thanks.

john

[johnsonx42]

Somewhere I saw sub say that the code he uses for reading/streaming files was written for use on a local hard drive, and don't play well over a network (lots of small reads I think). A 100mbit wired network is fast enough most of the time, but the additional latency of wireless causes the whole thing to fall off a cliff. I don't think its directly a bandwidth issue, its more on the latency side of things.

Keep in mind also though that the actual data throughput on a wireless connection is MUCH lower than the advertised data rate. An 802.11g connection will be lucky to get 25mbps actual throughput, and that assumes a good connection at the full 54mbps speed.

[unruelysock]

cool.

[Tikker]

Keep in mind also though that the actual data throughput on a wireless connection is MUCH lower than the advertised data rate. An 802.11g connection will be lucky to get 25mbps actual throughput, and that assumes a good connection at the full 54mbps speed.

this is because wireless is a half duplex system

802.11g is 27mbps in each direction

rule of thumb is to take advertised speed, and cut it into 1/3 and that should be the throughput to expect in normal situation

ie, wireless G should see 18-22 mpbs usually

[stustunz]

try file sharing instead of streaming
it only has to read the recording rather than the info go both ways at the same time
which is why wireless dont work well on streaming stuff it can only send packets one way at a time (half duplex)

wired lan= full duplex goes full speed both directions at the same time

[fpdave]

I think it might be a bit more complex that that.

I have a power network (200 Mbps dLan) (cos wifi is rubbish!) between my pvr recorder/server and my main wired network. I can copy a file from the pvr server at a rate of 6MB per second, but using a PVRX2 client it drops to only 3.5MB per second. The cpu on the server is only at 10% or less.

Oh, and it stutters pretty badly but is just about watchable.

I get similar problems using either streaming or file sharing - makes no difference.

[stustunz]

what about if you select it from the video library
i can get mine to work fine on both as long as the signal is 100% if it drops then it doesnt work so well
i think its your network or wireless card mine was doing bbetween 5-6MB/sec
also try a different rf channel
and there are other settings like turbo or fix to 54G only try switching them on and off

[ACTCMS]

I can play live TV and recordings over 11g wireless using streaming without any problems. Maybe try different decoders on your client - I use the MPV and MPA decoders from here.

[fpdave]

If I point it at a recorded mpeg then it plays flawlessly and only uses 0.6MB/sec!! This must be greatly compressed I suspect.

[imagn]

Somewhere I saw sub say that the code he uses for reading/streaming files was written for use on a local hard drive, and don't play well over a network (lots of small reads I think). A 100mbit wired network is fast enough most of the time, but the additional latency of wireless causes the whole thing to fall off a cliff. I don't think its directly a bandwidth issue, its more on the latency side of things.

I am thinking the same thing as i can use my laptop and access my files on my server wirelessly though windows networking, and can play my HD ts files perfectly.

I can not play these files without the latetcy issues described while using GBPVR.

This is not to say that wireless is a good option, it still has its issues