All About: Broadband Communications
2005-05-25
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 using a computer as an interactive TV) or video telephones. Broadband technologies have been around for a long time, but they have been too expensive in the past for the small business or the home user. This is currently changing with the arrival of Digital Subscriber Loop (DSL), which enabling cheap, high-speed communications across the last mile of wire between the telephone exchange and the socket on the wall.
Here we look at the DSL family of protocols and how they fit together. Business benefits are tempered with the current difficulties in rolling out DSL in various countries. We look at these and other deployment issues and consider where broadband is heading in the future.
What is Broadband OK, we lied. We have seen several definitions of broadband and its poor cousin, 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 Broadband constitutes sufficient bandwidth to permit the transmission of broadband services, i.e. 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 also takes into account the use of the term broadband in other spheres such as the Mobile Internet (for example, the 3G broadband protocol UMTS, which has an initial maximum of 384kbps).
Broadband communications have existed for years, at least for telecommunications providers (telcos) and the large corporations that can afford the extortionate costs. What has changed more recently is the development of a range of protocols known as Digital Subscriber Loop (DSL). The xDSL range (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 the fact that most data traffic will be to or from the Internet, we have another definition of broadband:
Broadband constitutes affordable, accessible bandwidth for the transmission of Internet-based broadband services via xDSL 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 will find Asynchronous DSL (ADSL) the most appropriate. ADSL is asynchronous in that the up channel is smaller than the 512Kbps down channel, a model which fits the standard usage pattern for the Internet 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.
Business Benefits of Broadband The technological benefit of xDSL-based broadband may be summarised as low-cost, high-speed, always-on access to the Internet. Given how much of a part todays Internet plays in the lives of most businesses, the positive impacts are linked to the business being able to do its Web-based dealings more cheaply and efficiently.
In addition, broadband access opens the door to a number of new ways to use the Internet for the business. For example:
If it has the right skills in-house, it may be more appropriate for the business to host its own information rather than relying on third parties such as ISPs. Conversely, the increased bandwidth opens the door for the business to make better use of externally hosted applications It is also appropriate to mention home use of ADSL. A high-bandwidth connection from the house to the Internet eases the possibility of teleworking (working from home), as corporate systems can be accessed as if the home user was in the office.
Deploying Broadband in the Corporate Environment So is broadband deployment as simple as making a call to a service provider, and asking them to come and fit a box on the wall? Well, largely, yes.
Issues with Broadband There are plenty of things wrong with current broadband, not least in its 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. Some telcos (for example, British Telecom in the UK) have a reputation for heel-dragging and for playing the system to prevent other providers from installing their own facilities.
ADSL (and cable, for that matter) also have a reputation for non-optimal performance. The down bandwidth is a maximum that is then reduced as more users access the facilities of the local exchange.
Last but not least is security. ADSL connections are always-on in two directions if you can get out, others can get in. There is a real risk that your computer will be attacked, hacked or otherwise misused (for example, as a base to send Spam e-mail).
The Future of Broadband The first next step for broadband is the completion of its roll-out this looks likely to take a good couple of years, particularly outside metropolitan areas. Broadband will be remembered not for what it is after all, it is no more than a high bandwidth socket ion the wall to most but what it enables.