ADSL2+: Turbo-charged broadband, at last

What is ADSL2+?
ADSL2+ is a souped-up version of ADSL (Asymmetric Digital Subscriber Line) technology, which transmits data using a certain frequency range on the copper 'local loop' cable connecting the phone in your house with your local telephone exchange.

When it was first introduced, ADSL was a significant step forward in Internet access, since it didn't require the availability of cable service and could coexist with voice phone services.

Other types of DSL, such as SDSL (Symmetric Digital Subscriber Line), are used by businesses requiring a particular type of connection, but ADSL proved ideal for Internet use, with a download channel many times faster than its upload channel.

ADSL1 performance varies with distance from the exchange, but could reach 8 megabits per second (Mbps) within 1.5km of the exchange. Telstra has previously limited ADSL1 to 1.5Mbps downstream and 256kbps upstream, but on 10 November the telco uncapped ADSL1 to allow up to 8Mbps downstream and 384kbps upstream.

ADSL2+, officially known as ITU G.992.5, boosts the download channel to a maximum of 24Mbps and offers a more modest increase to upstream speeds to let you send data at around 1Mbps (some ISPs such as Internode have started trialling boosted upstream speeds up to 2.5Mbps, under the 'Annex M' standard).

It does this through tweaking of the methods ADSL used to push data over your last-mile wire, with new technologies improving transmission efficiency and providing greater resilience to noise. (As a side note, don't confuse ADSL2+ with ADSL2 [ITU G992.3 and 992.4], a short-lived improvement on ADSL that was simply passed over in Australia and most other countries.)

Some providers such as iiNet, Internode, Adam Internet and others have been offering uncapped ADSL1 and ADSL2+ speeds in limited areas for some time.

Why do I need higher speeds?
Upstream speed is mainly important if you frequently send pictures or video to people, but the increased download speeds of ADSL2+ will be the real kicker, since it will deliver content at far faster speeds and enable the rapid transport of massive files, particularly videos and feature films.

If you're a big iPod user, for example, that means you will be able to download a feature-length movie from Apple's iTunes Store about 15 times faster than you could under the old 1.5Mbps speeds offered by most ISPs -- whenever Apple gets around to releasing movies on the Australian version of the store, that is.

Indeed, movie downloads will be an obvious early target for any ADSL2+ provider: in July, for example, ADSL2+ aspirant Netspace snatched up online DVD rental service WebFlicks. This deal gives Netspace a relatively successful real-world movie distribution business which, when backed by a high-speed ADSL2+ service, would seemingly pave the way for downloads on demand.

Telstra already offers some movie downloads through its BigPond Movies site, and does not count data from that site towards the download quota of its broadband services.

Although video downloads will likely be a popular first destination for ADSL2+ users, the overall faster Web experience will also pave the way for home users to broaden their use of a range of data services.

With that much bandwidth coming into your home, it will be possible for a single data connection to support multiple Internet radio, videoconferencing, voice over IP (VoIP) and even live TV signals at the same time -- and here's where it gets interesting.

Such 'triple-play' services have been talked about for many years, and are becoming a reality in other countries where more proactive carriers have worked overtime to bring new services to the market. In those environments, a single ISP could bundle data, voice and digital TV services over a single connection that does not, as is currently the case, have to be a cable TV connection.

ADSL2+ is your best bet for being able to buy decent triple-play services. A recent report by the national competition regulator found that ADSL was the most popular broadband technology Down Under, with around 72 percent of broadband services being ADSL.

Who's offering it?
Telstra is currently selling ADSL2+ in around 360 telephone exchanges in areas where competitors are already offering the higher speeds.

The telco could switch on a much wider rollout, but is believed to be holding back due to the desire to avoid being forced by the national competition regulator into offering ADSL2+ as a wholesale offering to competitors.

It is currently also offering uncapped ADSL1 up to 8Mbps in those exchanges, in addition to a further 2400.

Telstra's high speed (uncapped ADSL1 or ADSL2+) service is relatively expensive compared with other offerings, ranging from AU$59.95/month for a download limit of 600MB, to AU$149.95 for 60GB.

To realistically utilise video services you'll need Telstra's AU$89.95/12GB plan at least. And watch out for the excess download charge -- AU$150/GB.

A number of other companies also offer uncapped ADSL1 and ADSL2+ services, using their own networks or wholesale services provided by other telcos than Telstra.

The second-largest ADSL2+ network in Australia is operated by iiNet, reaching more than 260 exchanges. iiNet's prices are generally better than Telstra's, and the telco offers additional services such as VoIP services that can cut down your phone bill. However, cheaper offerings do exist.

Optus is in the middle of its ADSL2+ rollout, which in September reached some 150 exchanges. The telco offers competitive prices, although to get the higher ADSL2+ speeds you'll need to have your telephone with Optus as well.

In fact all three of these telcos give you extra benefits such as cheaper prices or higher speeds when you bundle telephone and ADSL broadband together with them.

Behind the big three are a range of smaller ISPs that are, at least in some way, providing services off the back of networks built by iiNet, Optus or Telstra. However many of them also have their own infrastructure in some areas.

Some major ISPs in this category include Internode, TPG, Adam Internet, Primus Telecom, Amcom, Westnet and AAPT.

Unfortunately for potential customers in rural areas, in general terms the rollouts are focusing on inner-city exchanges. They will, in time, extend out to the suburbs and beyond.

NetComm NB9W ADSL2+ wireless broadband router with VoIP gateway. Read the review.

What do I need to get it?
For now, the best way to decide whether you can get ADSL2+ is to drop by the various providers' Web pages and enter your phone number. Many sites offer a rollout schedule, with aggressive plans to build out the networks throughout next year and beyond.

To get those speeds, you'll need an ADSL2+ capable modem, which is already available from a number of vendors including Netgear, Linksys, Netcomm and other hardware makers. Many of these modems will be bundled with wireless routers, print servers, VoIP gateways, and other network gear to help you share your newfound broadband freedom around the house.

The good news: if you're an existing ADSL customer, you can keep your current modem and sign up for an ADSL2+ service that will deliver up to the full ADSL1 speed of 8Mbps without any modifications. You can then wait until the right ADSL2+ device hits the market before investing the additional money.

It won't happen overnight, but strong movement in the market confirms that ADSL2+ will quickly become a joyous reality for Australians over the next year. If you're feeling the broadband pinch -- or have never seen a reason to buy into broadband before -- be sure to watch the market closely. Fast Web surfing may have been the end of the line for ADSL1, but with ADSL2+ it's only the beginning.

Renai LeMay from ZDNet Australia contributed to this report.