98.8 PC CLient bandwidth

[idkpmiller]

Hi,

I love the new PC Client option, but it appears to be using around 12Mbps on my wifi connection this seems excessive. I am wondering if the amount of bandwidth is related to the capture quality that I am set to, as I was using live TV viewing while GBPVR was part the way through recording, i.e., I got the do you want to cancel the recording or watch the recording message come up after selecting Live TV.

I seem to recall (from aging memory) that sky NZ only tranmit at a rate of 3Mbps per channel if thats correct then perhaps I should be changing the quality I record at, which is currently set to the "live tv" setting thats shipped with GBPVR

Any advice welcome.

Thanks

[HtV]

You could certainly try to lower your livetv-setting as it is pretty high by default.
Another thing is that watching livetv while it is being recorded takes extra bandwith (upstream) because every 2 secs the client is checking the length of the recording.
http://forums.nextpvr.com/showthread.php?t=19558

[pastro]

Don't forget that there is quite a bit of MAC overhead on a wireless system. Depends on the system, but 50%-60% efficiency is typical. It can be much worse for mixed mode systems (G and B) since many implementations send a B burst before the G burst to hold off any B clients. It does this by essentially sending a value that tells the clients the air is busy for x amount of time so the G burst can be sent during this time. Since the B burst is really slow this sucks up bandwidth and no data is actually sent here.
If possible, set your system for G only. At the least, set for short training on the B.
Course if your PVR is on a wireless link and your player is wireless that's even worse since unless you are running adhoc, it has to run through the access point and that doubles the amount of data sent.
What I am really saying is that 12 meg to deliver 6 is expected.

[sub]

The traffic for client streaming mode while watching live tv is approximately the bitrate + 20%.

[pastro]

Are you talking wireless? Wired ethernet is more effcient since it doesn't have training sequences and legacy protection etc. Wireless efficiency rarely goes above 65% for distributed control (DCS).

[sub]

Are you talking wireless? Wired ethernet is more effcient since it doesn't have training sequences and legacy protection etc. Wireless efficiency rarely goes above 65% for distributed control (DCS).

Are you asking me or someone else in this thread? My comment above relates to GB-PVR's specific data requirements (regardless of network). Sure, the network transport you are using will add its own overheads on top of this, and these can vary quite a bit depending on what exactly you're using.

[HtV]

In my wireless 54g network it uses about 60-70 % on top of the bitrate.

[pastro]

Sub, I was asking you. Sorry for the confusion. I thought your bandwidth number was the actual network throughput number not the raw data rate requirement.
Anyway, all I was trying to say was that wireless networks are not as MAC efficient as wired espicially if you have legacy B clients.

[idkpmiller]

Thanks for all your input, I am quite aware of the additional overheads that comes with Wifi, I am more interested in the relationship to the quality that is set for video capture. I have a Dreambox as well as my GBPVR machine and I can easily stream live SKytv from the dreambox over 802.11b at the same time another PC can stream music from a NAS all are connected via wifi 802.11b. the quality is superb when streaming from the dreambox so I would say from a visual perspective its the same quality as what I see from GBPVR PC Client. I will do some experimenting this weekend and try and see what can be done if anything to reduce the bandwidth while maintaining reasonable quality

I'll let u know if I find anything of interest otherwise I will stay quiet and fade into the background :-)