A quick summary of broadband terminology
What is broadband?
When broadband first appeared in the UK in 1999, it was characterised by two things: it was always on, allowing customers to surf the internet and make phone calls at the same time, and the speed of data transfer was faster than that of dial-up modems. Today the term “broadband” has become synonymous with always-on access to the internet, regardless of the technology that is used to access the network.
What is superfast broadband?
Superfast broadband is a phrase used in the UK to describe faster broadband. This expression does not have a strict definition, but Ofcom and others are now using it to describe broadband speeds greater than 24 Mbps. The significance of 24 Mbps is that this is currently the maximum headline speed for broadband over existing copper telephone lines.
What is NGA?
The majority of homes and small businesses in the UK currently receive broadband services through the access network that connects them to their local telephone exchange via a twisted-pair copper cable. The term next-generation access (NGA) describes a significant upgrade to the access network.
There is no universal definition for NGA, but it is generally accepted that it includes fibre-rich infrastructure and technologies such as fibre-to-the-cabinet (FTTC), fibre-to-the-home or premises (FTTH/FTTP) and upgraded broadband cable TV networks.
In NGA networks, some or all of the copper in the network has been replaced with fibre. Since fibre is capable of sustaining higher data transmission speeds over much longer distances than twisted-pair or coaxial cable, NGA enables faster broadband.
What about wireless?
Fixed wireless access technologies such as Wi-Fi and WiMax are being used to deliver broadband services today, but they are not a substitute for fibre; indeed any high-speed wireless installation needs fibre to link the transmitters to the core network. While adequate for today’s broadband needs, Ofcom’s research suggests that wireless is not likely to be a cost-effective way to deliver superfast broadband, except in specific cases, probably in rural areas.
Mobile networks are also evolving rapidly to support internet access. The role of mobile broadband is still being debated, and for the next few years at least it is expected to fill a niche function – allowing access to the internet on the move. It is not expected to be a direct substitute for fixed-line superfast broadband.
Bandwidth, bits and bytes
The performance of a broadband connection is described by its speed, also called its bandwidth. This is the amount of digital data that can be transmitted in a given time, measured in bits per second. A bit is the smallest unit of information, either 0 or 1, in the digital language of computers.
Dial-up modems connected at 56 kilobits per second (kbps). Today the average download speed of broadband connections in the UK is nearly 100 times faster at 5.2 million bits per second (Mbps), according to a study carried out in May 2010 by Ofcom with technical partner Samknows.
Data consumption, like hard disk capacity, is measured in bytes rather than bits, where a byte is composed of 8 bits. A typical email is just a few thousand bytes (kilobytes or kB), while standard quality BBC iPlayer requires a continuous 800kbps of bandwidth, so watching a 30 minute programme would consume 180 million bytes (megabytes or MB) of data.
A number of internet service providers in the UK have introduced bandwidth allowances, which place an upper limit on the total amount of data consumed during the month, typically 10 billion bytes (gigabytes or GB) for any entry-level broadband account. Consumers exceeding their allowance may incur penalties, such as an additional charge on their bill or throttling, where the speed of the connection is reduced for a period.
A 10GB data allowance will allow hundreds of hours of basic web browsing, but it is not particularly generous for streaming video. Future applications are likely to make heavier use of video. For example, streaming just seven minutes of HDTV video at 20Mbps would consume a massive 1 GB.
Most broadband services in the UK are asymmetric, which means that the bandwidth available for downloads (from the network to the user) is usually far greater than that available for uploads (from the user to the network). Upload speed is becoming more important as people change from consumers to creators of content, uploading photographs and video clips to the internet and using interactive services based on two-way video communication.
Hi Pauline,
I think your definitions above are helpful. You might also be interested in some work I did with the National Education Network to define broadband entitlement in a schools and education context. This is mentioned in a post on my blog at:
http://broadbandpolicy.blogspot.com/2010/08/profiling-broadband-usagefcc-broadband.html
See the link to the paper Building a broadband entitlement. My post also references a recent report on broadband performance from the FCC, which categories usage in terms of the applications that a connection supports, rather than bandwidth.
I think is a more accessible way to explain broadband: with this type of connection you can do x, but with this type of connection you can do x, y and z (as well as x much quicker of course).
And if you’re one of a currently select few, you can do x, y and z and potentially a, b, c, d, e and f as well!
Hope this helps,
Jon Hunt
You might want to add “air link” or “over-the-air link” to your wireless section. This is a type of fixed wireless that is focused rather than scatter cast. It can be either radio (e.g. the old microwave towers) or laser (e.g. two office buildings on either side of a business park / river / highway). This is the sort of connection used when a landline would either cost too much or take too long to install.
Your modem reference needs a strong caveat – 56kbps modems are labeled with PEAK speed rather than constant speed. This is the same “Up to …” Newspeak that the DSL / cable-modem pushers use. The real speed depends on the quality of the connection you get when you call your ISP. My usual steady connection is just over 4KB/s with a good connection and can drop down to under 3KB/s when it is poor. Thanks to modem-to-modem compression I do see an occasional spike to 16KB/s but then the datagraph (my dialer’s speedometer) returns to the usual 4KB/s steady-state. (Downloading PDF’s and tarballs [a type of zip file] of up to 30 MB [thirty megabytes] gives me a two to three hour window in which to observe my datagraph.)