Alternatives to the obsolete Internet connection technologies offered by BT
This document serves as a summary of some of the main Internet access technologies available today. Here we look at some of the problems with these technologies and what they offer. Any corrections or feedback to: BTHateWorld
Cable Modems
Probably the future for most users in the UK if BT don’t install their own fibre network. Speeds would be expected to rise rapidly towards around 50-100Mbit over the next 5-10 years. Check out some of the cable providers (links on our home page). NTL is the only provider in our local area, but their services are not available to everyone yet. I've yet to see an NTL cable modem, but I'm sure the results will be favorable to BT ADSL.
Problems:
Contention ratio: at local junction boxes there is only finite bandwidth available to connect to the backbone capacity
ADSL
View the page on ADSL
technologies
Problems:
Contention ratio: BT exchanges, being designed for voice traffic, probably don’t have the bandwidth to deal with large numbers of ADSL connections.
Cabling: Copper cabling, especially of the quality used for telephone lines, will ultimately be the factor which limits bandwidth. This limits the future value of ADSL and its lifespan to a few years at most.
RF: Testing seems to suggest that AM radio can interfere with DSL and different types of DSL may interfere with each other. DSL is also rumored to interfere with AM radio, but this is pretty much obsolete now anyway.
ISDN
Integrated Services Digital Network. Higher bandwidth versions of this service do offer reasonable data rates, but only over expensive leased lines. In the UK these lines are priced well out of the reach of the ordinary consumer so that BT can make higher margins in one of the areas of BT's business that has not yet been hit much by the recent decline in their excessive profits. This is why ADSL has been delayed so often by BT and this is also the reason that BT ADSL is slower than it could otherwise be.
Problems:
Obsolete: Not worth investing in. Will shortly be replaced by newer technologies.
Cost: BT has long overpriced ISDN services. Home Highway, for example, was certainly not available at a home user price point.
Cost of usage: With ISDN2e and both channels open for any length of time, cost was excessive.
Data transmission over electricity network
Supposed to be introduced in some areas. In practice, this technology has not worked as well as has been expected.
Problems:
Interference
RF
Limited bandwidth for many users within locality
Worth the investment. Requirements for bandwidth are likely to increase rapidly. This technology is unlikely to keep pace with increasing bandwidth requirements.
400kbit/sec upwards. Upstream link is modem. In near future Ka band 64Mbit/sec downstream 2Mbit/sec upstream services are expected to appear. Future versions may also have an upstream link to the satellite.
Problems:
Radio bands available?: Finite spectra allocated to this type of usage. Large number of users may not be able to be supported.
Upstream link speed: Upstream link on most current services is still over a slow modem.
Cost
Number of users that a single satellite can support
Apparently, Atlantic Telecom offer services as fast as 2Mbit over radio and 4th generation cellular technology is heading towards 20Mbit (not for a few years yet though). It is unbelievable to think that radio access developments will outpace those for land lines, but the fact that the development of some of these services is announced before that of faster landlines in the UK is somewhat indicative of the fact that the principle of investment is foreign to BT.
Problems:
Radio bands available?: Enough of radio spectra available for widespread deployment
Radiation concerns