tommy.irene

Are you telling me you didnt look to see what the link was about??..

HeikeundAlan

Cool thats saved to my bookmarks thank you

MikeJ

I did but all I got was screen of channel logos which when I pressed them showed a blank screen. I thought, in the context of the conversation, that it would connect me to a Wimax service.

tommy.irene

You should give the blank screen time to put on a programe you picked..

Domino

What
Only "nearly right"

are you are saying that signal loss isn't due to resistance ??

and are you saying that "induced" intereference such as a street light, a fridge or freezer or arc welding is going to cause the internet to run slow ??

most of those are "local" problems and most of the BE people aren't watching Corrie whilst doing abit of arc welding on the side.
they show up as blips on a frequency analyser not as constant reason for the signal having problems getting to the end of the line - in the same way as a long hose pipe has difficulty in maintaining pressure at the end of the run.

seperation is generally good for the runs of telephone cable, even in Spain, induced interference is also generally rare - especially if the cables are more than 12 inches apart.
Thats one of the reasons for using twisted pair or mult-twisted pair.

hth

MikeJ

strictly speaking resistance applies to DC cables, impedance (or more accurately reactance) is the attributes of transmission wires.

ADSL over unscreened twisted pair (UTP) Cat3 cabling normally used for voice telephone cables can offer up to 4kms from the exchange (in ideal conditions), over Cat7 screened twisted pair (F/FTP or F/STP) can provide up to 12kms. I suspect that most of Spain outside the big conurbations are still UTP telephone cables.

The latest ISDN transmission technology is VSDL which can offer up to 400mbs at subscriber premises but uses a completely different topology to conventional telephone cables. It is based on a short local loop in twisted pair (between 16 to 20 premises) connected to a cabinet. The BT version Openreach uses fibre optic to cabinet (FTTC) technology to transmit the signals to the locality and VDSL local loop for the final connections. Telefonica have a limited deployment of VDSL in the Madrid region but I have no idea what the plans for wider deployment are - although, unlike the UK, the campo is likely to be quite low on the list.

Local electromagnetic interference can lead to 'slow' internet. This because TCP/IP protocol is essentially a packet switching protocol. DTV requires the packets to arrive in the correct order, and the transmission protocols for DTV have some very complicated algorithms to ensure that packets are in the right order and to compensate for missing packets (which can be caused by local interference) this takes a finite time and would appear as 'slow' internet. Actually the most common reason for 'slow' internet is insufficient bandwidth to support the data rates of DTV, which leads to packet dropping, correction attempts and buffering all of which can make live/streaming TV problematical in many areas outside the more highly cabled regions of Spain (and anywhere else for that matter). The best way to view HDTV is by downloading the program, local caching and viewing.

All of which, of course, requires a connection to the service provider.

Fred James

Agreed, but not all streams are easily downloadable.

BBC iPlayer is, and the HD stream is 720p. That's the method I have found most acceptable. Hopefully ITV will add a HD download facility to their iPlayer.

lutonlad

Good explanation. It's my understanding that the Transport layer of the TCP/IP model also handles Retransmissions where necessary - eg. in the case of excessive noise or interference. This could slow things down.

Jon-Bxl

Hi Wow this is really interesting, thanks Fred.

I need a proxy before I can use eg BBC iplayer... so I don't have any experience with it, but I like the idea of downloading/caching and watching later.

Is it 'easy' to cache a stream on hard disk, e.g go out; download to disk whilst having a beer; come back and have it ready to watch?

What would be needed please,

1) with the i-players to do this...........
..................and

2) Can this be done with any streaming video , please? This would be great to download when out, come back and watch at my leisure and and stop any 'real time screen jitters' ........ and be able to fast forward through the ads etc...

3) Also if I did it overnight, could I be downloading a few things at the same time, please?

(Non-super-techie answer please!)

I'm OK with watching in SD as it happens, far better than with nothing at all, so I would deliberately do that if I had a choice to reduce download time.

Thanks in advance for any explanation on how to do this in practice..
Jon

Ps just had a thought, if the signal coming in is 'jittery' then it will record jittery..... Unless there is some sort of 'error checking' between sender and receiver to ensure that what is received is what was sent.... I.e a 'perfect copy' received, is this actually possible, please?

Fred James

I can only speak from experience with BBC iPlayer.

Yes, you do need a Smart DNS or VPN but they are cheap and easy to install. You can watch and download on your PC. If you connect it to your TV then you can watch is full size. The BBC offers a SD and HD stream. You need about 2mb for SD and about 3.5mb for HD.

There is an option to download in either SD or HD. Connection speed is not an issue as it just takes longer on a slow connection. On my 2.5mb connection one hour of HD takes about one hour to download and uses just over 1GB of storage.

You install the BBC download manager on your PC which handles it all for you and you can download as many programs as you like at the same time. If it hits any connection problems it pauses and restarts a few minutes later. The programs on BBC iPlayer are usually only available for 7 days after the broadcast but if you download them, they will be playable on your PC for 30 days. Once you start watching one you have 7 days to finish it.

If you have a tablet you can do the same. I have an iMac and an Apple TV and the iMac can stream directly to the TV via the Apple TV. If you have an iPad or iPhone you can also stream to the TV through the Apple TV.

The Apple TV is badly named - everyone thinks it's a TV - it's not, it's just a set top box the same size as all these other IPTV boxes, which allows to to stream media through it using a WiFi protocol called Airplay. It connects to iTunes on your PC and will stream your music/photo/video connection and also allow you to download films in full 1080p Bluray quality from the iTunes store. It can also access almost any radio stream anywhere. It costs £99.

Although it works best with an Apple device, there is a little program that you can run on a PC called AirParrot which gives your PC the same steaming facilities as you get on an Apple device. Free to try on a trial, but only $10 to register. http://www.airsquirrels.com/airparrot/

ITV does not allow downloads, but from their blog it seems like they may be considering it. As yet, C4 and C5 don't offer downloads and none of them, apart from the BBC offer a HD stream - or if they do I haven't found it yet. C4 does allow downloads via the IOS or Android app but not to a PC.

Jon-Bxl

Thanks Fred for taking the time to explain all this for me/us.

This is extremely interesting!

Jon

MikeJ

Hi Jon
Strictly speaking "streaming" means data transfer in realtime whereas "downloading" is as it suggests: storing/caching the content. Fred has give a good explanation of how you can use downloading I'm not sure thare is much point in storing 'streamed' content if it is not good quality, however the obvious way would be to your local DTV recorder

Hopefully see you in the summer.

BILL AND CLAIRE

Tommy. Its a bit over the top calling Mike a prick...

MikeJ

No offence taken, a lot of people have said that

BILL AND CLAIRE

QUOTE=MikeJ;11132819]No offence taken, a lot of people have said that [/QUOTE]