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What's the fuss about... broadband communications

A back to basics explanation
Written by silicon.com staff, Contributor

A back to basics explanation

You've heard of broadband, maybe heard how we should all have it. Why should we? Here's an overview, lest you forget what to tell the boss, courtesy of Quocirca analyst John Collins...

Broadband is a simple enough term to understand, at least for the person who is going to use it. At Quocirca, we have seen several definitions of new-and-improved broadband and its poor cousin, old-and-inferior narrowband:

Broadband corresponds to multiple voice channels in a telecommunications circuit, whereas narrowband corresponds to only one.

Broadband corresponds to a data rate of over 1Mbps (even if governments have their own definitions).

Broadband constitutes sufficient bandwidth to permit the transmission of broadband services, namely streamed multimedia, videoconferencing and the like.

The third definition may appear a little vacuous but it is the one we favour because it concentrates on the end rather than the means. It allows more technological flexibility, for example for data compression or caching of streamed media rather than 'pure' bandwidth, and it also takes into account the use of the term in spheres such as the 3G 'broadband' also known as UMTS in Europe, which has an initial maximum of 384Kbps.

Broadband is as much a state of mind as a technology, defined in terms of what it enables rather than what it is - the transmission of sufficient quantities of information to enable such applications as multimedia streaming (think of using a computer as an interactive TV) or video telephones.

Broadband communications have existed for years, at least for telecommunications providers (telcos) and the large corporations that could afford the extortionate costs. What has changed over the past couple of years is the development of a range of protocols known as Digital Subscriber Line (DSL). The xDSL range (where 'x' stands for 'whatever') enables transmission of very high data rates across the so-called 'last mile' - the pairs of wires that run from local telephone exchanges to homes and offices. Given that most data traffic will be to or from the internet, Quocirca proposes another definition of broadband:

Broadband constitutes affordable, accessible bandwidth for the transmission of internet-based broadband services without needing major modifications to existing infrastructure.

xDSL is a range of protocols, each of which is more applicable to certain needs. Most smaller organisations and home users (those who BT has deigned to connect, that is) are finding Asymmetrical DSL (ADSL) the most appropriate. ADSL is asymmetrical in that the 'up' channel is smaller than the 512Kbps 'down' channel, a model which fits internet usage patterns in which more information is generally received than sent. A further strength of ADSL is that it is 'always-on' - there is no need to dial up to the internet.

Symmetrical DSL (up equals down) is more appropriate for businesses, for example enabling inter-site or inter-company communications.

In addition to the low-cost, high-speed, always-on access to the internet xDSL provides, enabling businesses to do their web-based dealings more cheaply and efficiently, broadband access opens the door to a number of new ways for a business to use the internet. For example, if it has the right skills in-house, it may be more appropriate for a business to host its own information rather than relying on third parties such as internet service providers (ISPs).

Conversely, the increased bandwidth opens the door for the business to make better use of externally hosted services such as those provided by application service providers (ASPs). These companies have had a bit of a bad press, largely due to their dubious grasp of their middle name ('service') but also because of the lack of available bandwidth to take advantage of the service. It is all very well having 100 megabytes of storage space, for example, but this is of minimal comfort if it is only accessible over a modem link. There are companies, such as eProject.com and Salesforce.com, that have proved the workability of the ASP model, but they've required sufficient bandwidth to make their services workable.

There are plenty of things wrong with broadband, not least in its UK availability. Our definition is from the point of view of the end user and not the telco, who must roll out ADSL equipment to all its local exchanges. BT has a hard-earned reputation for heel-dragging and for playing the system to prevent other providers from installing their own facilities. The end result remains 'no service available at present' situations, particularly outside metropolitan areas.

Even when it's up, ADSL has a reputation for non-optimal performance. The 'down' bandwidth is a maximum that is then reduced as more users access the facilities of a local exchange. What's more, a fully contended consumer ADSL line (50:1) gives a lower possible throughput than a clean 56K modem. Read all about it - it's in the small print.

Once the other issues are ironed out, it is likely that security will gain the major issue with always-on broadband. ADSL connections are always-on in two directions - if you can get out, others can get in. There is a real risk that always-connected computers will be attacked, hacked or otherwise misused (for example, as a base to send spam email).

The next step for broadband is the eventual completion of its roll out. This looks likely to take a good few years, though the technology and the will (in most quarters) is available now. Broadband will be remembered not for what it is - no more than a high-bandwidth socket on the wall to most - but what it enables. **Quocirca is a leading, user-facing analyst house known for its focus on the 'big picture'. For a full summary of its activities see www.quocirca.com, or reach the company's founding directors by emailing quocirca@silicon.com.

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