Internet access terminology can be very confusing, especially if you’re trying to choose a new ISP. Each technology has its differences and some may be better at certain tasks than others, consequently it is important for consumers to understand the advantages and disadvantages of each prior to choosing a provider. This page seeks to explain the methods using simple language and is best used in conjunction with our 'Jargon Buster
Cable defines a network that uses robust fibre optic or coaxial cabling to connect its service with consumers, which can carry significantly larger amounts of data than a standard copper telephone line (POTS). This enables operators to deliver Internet access, television and phone services over a single connection. Cable broadband services are significantly faster and more reliable than DSL (e.g. ADSL) technologies, reaching 100Mbps and higher in the future. The most common UK forms of superfast fibre optic and cable technologies are explained below.
- Cable Modem (DOCSIS)
Cable services are currently delivered by less than a handful of UK ISPs, although Virgin Media is the only one of any real national scale and covers almost 50% of the country. Related services run over a mix of high-grade coaxial and some fibre optic cable. Most cable networks install fibre to a node (cable's equivalent of a telephone exchange) and then deliver their connection to homes via a short run of copper or coaxial wire.
These networks usually make use of the Data Over Cable Service Interface Specification (DOCSIS), which is an international standard for defining the communications and operation support interface requirements of a data over cable system. DOCSIS3 is capable of reaching speeds of over 400Mbps using 8 channel bonding. Sadly you can't mix and match different providers and services on a cable line, they must all come from one operator and will often need an engineer installation.
- Fibre To The Home/Premises (FTTH/P)
The latest Fibre To The Home / Premises (FTTH / P) services, most of which will come from BT by 2015 (2.5 Million UK premises), work by delivering a pure fibre optic line directly to your doorstep. True fibre optic lines send and receive information at the 'Speed of Light' by transmitting tiny pulses of light down a glass (silica) fibre cable, which means that symmetric performance of up to 1Gbps (roughly 1000Mbps) is possible (consumer packages usually begin at 100Mbps).
This is widely regarded as being one of the fastest and most future proof methods of communication. Sadly FTTH coverage is often only found in urban areas (towns and cities) because it requires a lot of practical and expensive work (e.g. roadwork's) to build the networks, yet the service itself is usually well priced, reliable and very flexible. One negative is that FTTH services require a power source and as a result any outage in your electricity supply could result in downtime, although a short lived backup battery does provide some limited protection.
- Fibre To The Cabinet (FTTC)
BT and several smaller niche operators, such as Digital Region and Rutland Telecom, are currently in the process deploying Fibre To The Cabinet (FTTC) technology out to over 66% of the country by 2015. This halfway house method craftily runs a fibre optic line from the nearest telephone exchange to your local street cabinet. The "last mile" connectivity from cabinet to your home is then done by using VDSL2 (see the 'Broadband DSL' section) technology over your existing copper phone lines.
The extra copper in FTTC makes related services slower than full FTTH and more susceptible to performance problems over distance, although unlike FTTH you won't lose your connection if the power goes down because the telecoms network can use its own isolated electricity supply. Being cheaper to deploy also makes it affordable for home users and the technology is a lot more reliable than DSL too.
Service speeds of up to 40Mbps download and 10Mbps upload are the current standard, which will rise to 80Mbps download and 20Mbps upload in 2012 (BT claims that 100Mbps could be possible in the future). Generally speaking you need to live about 400 metres or less from your street cabinet to get the best performance, while some people who reside over 2000 metres (2km) away have reported speeds of 16Mbps. Ofcom reports that FTTC ISPs deliver an average real-world service speed of over 30Mbps.
Sadly FTTC services require an engineer installation and this attracts a one-off setup fee of around £100. Customers can also expect to pay a +£10 premium for related services in comparison to traditional but slower ADSL services.
It's important to point out that the above services are likely to completely replace existing DSL solutions over the next five to ten years. Sadly Ofcom also has yet to establish a firm standard for migration between different fibre and cable operators, although they are current investigating the possibility.
- Very fast download speeds and can go even faster.
- Very fast uploads (only FTTH/P/C).
- Low latency.
- Affordable packages, especially with bundled TV and Voice services.
Related ISPreview Sections:
- Currently only moderate to low coverage.
- Moderate upload performance via DOCSIS.
- Costly FTTH/P/C setup.
- Expensive to deploy FTTH and DOCSIS to new areas.