Find everything you ever wanted to know about Very‑high‑speed Digital Subscriber Lines at the DSL Forum.
An ADSL telephone line can improve the speed and convenience of Internet access enormously — and it needn't cost the earth. Dave Shapton passes on his experiences of the new technology.
I can hardly believe it — I've got ADSL (Asymmetric Digital Subscriber Line) at last. That's the good news. The bad news is that it's at the place where I work, so I have trivia like 'earning a living' to get in the way of playing with it. (Luckily, we are a digital media company and I have to do a fair bit of web browsing anyway.) The biggest surprise of all is that BT installed our ADSL connection on time. We applied for our connection on the day ADSL was announced and had it on the first day it was available anywhere in London.
A Fast Line
Get the best of both worlds with Kerbango's Internet radio, which also functions as a normal AM/FM radio.
We opted for the 512Kbit per second connection because that's what most people will end up with, despite earlier suggestions, from BT and others, that 2Mbit/sec would be commonplace for home users. Still, even that's nearly 10 times better than the (at best) 56Kbit/sec that most of us still have to put up with. It's actually no bad thing that we only have 512Kbit/sec Internet access, because we do a lot of video and audio streaming tests on behalf of clients, and it gives us a chance to see what sort of quality people can realistically expect with their 'broadband' connections. (It's a bit like using Yamaha NS10s instead of monitor speakers the size of a wardrobe.) Oh, and it's cheaper as well.
What's it like using ADSL? Brilliant — with qualifications. What's good is that it's a permanent connection: you're always connected. Always. I have to keep repeating it because I still can't believe it. No more waiting for dodgy dial‑up connections. When you've got ADSL your browser just becomes another icon, openable at any time.
Downloads are simply stunning. What used to be a chore to be actively avoided because it was so painfully slow — and expensive, too — has become a fun activity. Now I search out big downloads so that I can marvel at the download speeds. On a good day with my modem I could manage download speeds in the region of 3‑5Kbytes/sec. Now I routinely get speeds of 30 to 40Kbytes/sec, and what a difference it makes. You don't even hesitate to download the biggest files, because they don't take long anyway and you're not paying by the minute. If you were ever tempted to download MP3 files, ADSL would allow this to be done faster than real time. In other words, a five‑minute track would take less than five minutes to download.
Even the most complex web pages flash up in an instant. Flash animations really work. Streamed music sounds fantastic. Streamed video looks — well, it looks better. There's still a long way to go with streamed video under about 750Kbits/sec.
What's not as good as you'd expect is that it still takes time to get to web pages, once you've entered the address in your web browser. But you have to realise that, however fast your connection to the Internet, the web itself still works the way it always has. Which means that every URL you put into your browser has to be sent to a domain name server for translation into a numerical Internet address, the unique number that every individually addressable web‑connected device has. This, as well as the time taken by the web server to respond to your request, can make the process of web browsing using ADSL seem, at times, no faster than using a modem. You just have to accept that having a faster connection to the Internet can reveal just how slow some aspects of it still are.
Another benefit of ADSL is that it's saved the company a fortune in comparison with our ISDN dial‑up costs. One way or another, there's always someone connected to the Internet at our place, and it's the fact that we just pay one monthly sum instead of a 'per call' charge that makes the difference.
Remarkably, the fact that there are over 20 people on our network, sharing the single ADSL connection, doesn't seem to slow it down at all. I suspect that the majority of our network users are looking at conventional HTML pages, which are small in data terms, and of course while people are reading them there is no data activity at all. If everyone were to watch a video stream at the same time, however, everything would slow to a crawl.
There have been times, though, when it hasn't worked at all. We went for a week without our high‑speed connection and it was agony to have to use ISDN again. This kind of unreliability is a pretty common story, I've heard, and of course it's easy to blame BT. However, to be fair, BT is going through its biggest period of change ever, and I think the occasional slip‑up, especially with an unproven technology like ADSL, is to be expected and is to some extent forgivable, however annoying.
So ADSL is a real option now, and it's being slowly rolled out. It's not cheap, but at between £20 and £40 a month it's certainly worth it if you've got more than a passing interest in the Internet.
A Very Very Fast Line
Sonicbox's Internet radio interface: radio for the 21st century?
Somewhat surprisingly, ADSL is nothing more than a transitional technology. Waiting around the corner is VDSL (Very‑high‑speed Digital Subscriber Line). It's a version of DSL that (wait for it) works at a very high speed. How high? Up to an incredible 60 MegaBits/sec. That's 10 times the fastest version of DSL, and 40 times faster than the version of DSL that most people will get in their homes. In fact, it's approaching the speed hard disks used to work at a few years ago. (If you want more facts than you'll probably ever need about VDSL, go and have a look at www.adsl.com/ vdsl_tutorial.html. It's worth reading, not least for the reference to that quaintly traditional American unit of measurement, the KiloFoot.)
Do we really need these speeds? Not if we're only web browsing. As I mentioned above, HTML doesn't need anything like this bandwidth. Proper TV viewing possibly does, though.
I've heard some interesting claims from Microsoft about the quality of their new Windows Media 7 (WM7) video encoder. It's part of the new suite of video and audio encoding algorithms released at the same time as Windows Media Player 7, and the video part actually uses an "enhancement" (Microsoft's word!) of the MPEG4 video codec. Before I say anything else, I want to say that it certainly looks very good, given the amount of compression, but it equally certainly isn't what Microsoft claim — which is that, at 750Kbits/sec, it is "near DVD" quality. If it's near DVD quality at that rate, I'm a near ballet dancer. You can certainly get pretty good, watchable video at around 750Kbits/sec, but it's only going to be between VHS and SVHS in quality.
Judge for yourself by looking at www.microsoft.com/windowsmedia and downloading some of the examples. (Note that they have used some very flattering images, which would look good at almost any data rate.) Microsoft also has some public domain competition, in the form of DIVX, which is claiming to be the "MP3 of video". Like the Microsoft codec, it's based on the video codec of MPEG4. There's more information about it at divx.ctw.cc/
What the 'on demand' video industry would really like is the ability to pipe MPEG2 down the line. MPEG2, which is what's used for DVD, has a data rate of between 4 and 11 Mbits/sec. A rate of 8Mbits/sec is good for almost everything but explosions and car chases, but that's way above what even the best implementation of ADSL can manage, especially when you consider that the stated raw bandwidth is almost never available because of transactional overheads and Internet bottlenecks.
True DVD quality and High Definition TV will need something much faster than ADSL, which is where VDSL fits in. The big fly in the ointment is that the faster the data link via standard copper wires, the shorter the distance over which it works. Wires, after all, work like aerials. Put radio frequency signals into them and they radiate!
The ultimate link to the Internet is fibre‑optical technology. We'll just have to wait for that, but when we get it I don't think we'll need to have any conversations about bandwidth at all.
Wired For The Web: Cable Internet
An alternative way of accessing the Internet, for those of us with cable, is using a cable modem. The sort of performance you can expect is likely to be around the lower end of the ADSL range, at about 512Kbits/sec. This is plenty fast enough for conventional browsing and excellent for 'web quality' video. Like BT's rival technology, it's an 'always on' connection. What remains to be seen is how well the service will stand up to heavy use: your connection speed is not guaranteed and will depend on the extent to which you have to share bandwidth with other users.
Still, I reckon cable is a good bet, not least because I think it's likely to be cheaper than ADSL, although you will have to buy or rent your cable modem. Expect prices to be around £150, or £5 per month.
Radio Head
Internet radio has already been written about in Net Notes, but there are sone new developments that could alter the way we listen to radio on the Internet.
I've always loved radio. As a child I used to collect old valve radios and go in search of exotic foreign stations on the short‑wave Broadcast bands. I'd fall asleep in the dim glow of my Grundig (with '3D sound', whatever that was) and dream of visiting Tirana, in the Marxist Leninist People's republic of Albania. If you don't have a short‑wave radio, go to www.intervalsignals.net to hear the interval signal for Radio Tirana. It's the strangest and possibly the most spine–tingling sound you'll have heard for a long time.
What the Internet can't bring you is the sound of the ever‑shifting ionospheric manipulation of radio signals, making already exotic, distant stations sound even more exciting and mysterious. In a way, the atmosphere is like a global analogue synthesizer. All the effects are there: phasing, LFOs, ring modulation, white noise, and, of course, distortion.
That's what radio was like in the last century. www.sonicbox.com shows us what it's going to be like in this one. Sonicbox have dispensed with the notion of a 'multi' media player and have created what looks just like a real radio — with knobs. The on‑screen version sports controls for volume and station selection, is very easy to use and has a good range of stations on‑tap. It's optimised for broadband use but is perfectly OK with a 56Kb/s modem, as long as you don't mind AM‑quality radio. Judging from the Sonicbox user settings, the site appears to use both Real Audio and Windows Media audio, whereas most radio stations on the Internet use one or other of these formats.
Sonicbox describe their version of Internet radio as the 'iM' band, as opposed to AM or FM. It's a neat idea, because it conceals the fact that what you're actually using is the Internet. To allow you to enhance the sensation that you're using a radio and not a computer, SonicBox have released hardware that lets you control the tuning on your computer remotely — for more details, look at their web site.
Yet another approach is taken by Kerbango (www.kerbango.com). They've made a stand‑alone Internet radio that's fashionably retro‑styled, attractive and, I think, odd in equal measures. It works as a normal AM/FM radio, as well as having Internet functionality. I'm really excited about this product, and not just because I really love Internet radio. It's because it's the first genuinely useful Internet appliance that I've seen. It doesn't try to be a personal organiser, mobile phone, satellite navigation unit, or a million other things. It's just a radio. But it's a radio that lets you listen in stereo to samba music from Venezuela, if that's your bag.
The short‑wave bands have been thinning out since the end of the Cold War, and the Internet could kill them off completely. That's a big loss. But what we've gained is the ability to tap into the rich diet of local stations that we could never get on the conventional radio bands. If you like world music, you'll love Internet Radio.