Real World Computing
Speed limits
When 3G first hit the airwaves in early 2003, it offered speed broadly comparable to the 128-512Kb/sec broadband landlines then available, and it felt amazing to get this much data through a handheld device. But wired broadband has moved on, and most of us should in theory be getting significantly more than 512Kb/sec. 3G has moved on, too. HSDPA (High-Speed Download Packet Access), also referred to as 3.5G, is a speed-boosting technology that increases the data throughput of existing UMTS networks, especially the download speed, hence the D in the name. There's also an HSUPA for fast uploads, although that's on the "coming soon" list for most of us. Much as with EDGE deployment, enabling HSDPA is usually just a matter of updating the firmware in cell towers.
Note that what I've described here is the situation in the UK and indeed most of Europe, but if you travel to the US you'll find that the main mobile networks operate using entirely different technologies - rather than GSM and UMTS they use CDMA (code division multiple access). Most 2G devices can cope with all these worldwide standards, but that isn't necessarily true for 3G, and mobile broadband dongles, for example, are often UMTS or CDMA-only. So be very careful if you're tempted to buy cheap kit on Ebay or elsewhere from a US vendor.
But to get back to Richard's original question, how should he be setting up his data dongle for optimum performance? You might well assume that the simplest option would be to just specify the fastest option, namely HSDPA only, and that's probably a reasonable thing to do if you're sitting in a hotel room in the West End of London. But what if you're somewhere out in the wilderness that only gets plain old 3G and not HSDPA? If your device has been told to use HSDPA only, then you'll be completely out of luck. So maybe "HSDPA preferred" is the best option then? Well yes, I think in most cases it probably will be, but there are a couple of exceptions even to this rule.
First, if you're in a location that has a very marginal 3G (and thus HSDPA) signal, you might find that the device can only barely maintain a 3G connection and that it keeps dropping out, in which case you might find that there's a good 2G (GPRS/EDGE) signal and you'd be better off forcing the dongle to connect at 2G speed, particularly where EDGE is available. The second exception is one that seems to be increasingly common in certain locations (the financial City area of London, for example), and that's where the mobile 3G networks have become very congested. If you have a good strong signal, but are struggling with slowly loading web pages, then try knocking the data dongle back to 2G and, although it's theoretically slower, you might find you're competing with fewer people and so get a faster and more even overall throughput. Incidentally, I'd be very interested to hear your experiences of data congestion on mobile networks: if you regularly have this problem, perhaps you'd be kind enough to drop me a quick email naming the network, location, and time of day when you've spotted it.
Watch out at the Outlet
I'll often write this column using my trusty old Dell Inspiron 9300. I like it because it has a great keyboard and a wonderful 17in WUXGA (1,920 x 1,200 pixel) screen, which means I can keep loads of apps open at once. It isn't the kind of "laptop" you'd actually want to use on your lap, and in fact you probably wouldn't even want to lug it around with you. A friend of mine (a past editor of this magazine) uses the same model, and calls it his "juggernaut", but as a sensible desktop replacement it's great. Or rather, it was great...
