ADSL - Asynchronous  Digital Subscriber Lines. This technology uses existing copper telephone wires to provide broadband access at any location with a phone line. At least, at any location with an analogue phone line (not ISDN) that's close to an updated telephone exchange. The roll-out of ADSL has been appallingly slow both in the UK and elsewhere. 

3G or UMTS - Third Generation Mobile. As widely reported, the incumbent mobile phone companies have paid multi-billion pound fees for their 3G UMTS licenses. Equally widely reported have been the delays in implementation of the service, with technology & equipment providers such as Qualcomm and handset providers such as Nokia both delaying the roll-out of 3G UMTS operation until 2005 - the earlier high profile launches in a part of Tokyo city and on the Isle of Mann were more related to PR than to telecommunications. The real start of service date is likely to slip further, and when it does happen the coverage will be limited for the first few years. 3G UMTS will have the capability of supporting limited video transmission in addition to voice and data, although the cost of video transmission is expected to be prohibitive.

2.5G or GPRS - General Packet Radio Service. Over the last few years GPRS had been fanfared as the next big thing in mobile communications. In the UK both Vodafone and Cellnet commenced trials but an operational service was shelved when it was thought that 3G UMTS was just around the corner. With the delays in 3G implementation there is renewed interest in 2.5G GPRS, however, it is NOT broadband. 2.5G GPRS provides data communication at up to 44kBit/s from the hub to the mobile user and at 9.6kBit/s from the mobile to the hub. It is suitable for limited web browsing but not for any form of video.

DTT – Digital Terrestrial Television. DTT is being rolled-out in many countries, but as it is squeezed-in amongst the existing analogue terrestrial transmissions it typically provides coverage of some 70% of the population. In the UK five DTT multiplexes are in operation giving a total capacity of 120MBit/s, all of which is currently dedicated to television broadcasting. Although there has been talk of additional bandwidth being released for data broadcasting applications there is no evidence to suggest that the regulators are willing to do so in the short term. In any event, if additional bandwidth were released, the law of diminishing marginal returns would apply to the coverage which would be significantly below 50%. Additionally, DTT could not provide any form of European or global coverage through a single source.

Cable. As a consumer, given a choice of cable or satellite the choice should be cable every time as it moves the responsibility for the infrastructure provision from the consumer to the operator. The consumer gets what he wants - one box and all of the services. However, cable is limited to a relatively limited coverage in most countries and is focussed on the domestic rather than the professional marketplace.

Satellite. Today and for the foreseeable future satellite remains the only technology that can deliver broadband connectivity to any/every location in a chosen country or region. This is particularly important for corporate or digital media networks where you have to deliver to 100% of (say) the stores of a supermarket chain, not just the x% of stores that can be reached by ADSL/3G/2.5G/DTT/cable. Satellite benefits from broad geographical coverage such as the whole of Europe or the whole of north America, and provides an exceptionally broad bandwidth pipe compared to the other mediums described above. For example, a 40cm Sky Digital antenna in the UK can receive multiple 40MBit/s channels up to a total capacity of around 3,200 MBit/s

Bandwidth summary: