Whilst there are no definitive indications of whether consumers will want significantly higher speeds, we are seeing evidence of increasing use of IPTV and other bandwidth hungry audio visual applications. This begs the question of when the current copper network would be unlikely to meet the expectations of the majority of UK consumers.

To give some insight, we commissioned a study based on an idealised environment that does not reflect all the complexities of the current underlying network. This abstraction enabled us consider the theoretical capacity limits of copper networks and set an upper bound for broadband data rates that could be achievable across copper. Given the important relationship of distance to data rate, we based our model on information on cable lengths from a real network.

We concluded that, in our idealised environment, capacities can further improve, compared to today’s deployments. We found that if the upstream modem is hosted in the exchange, households within 2km of the exchange (approximately 18% of the total number of households) could, in theory, receive data rates above 50Mbit/s. If the upstream modem is moved closer to the customer premises and into the street cabinet, then almost 100% of households are within 2km of the street cabinet and could, theoretically, expect a data rate of 50Mbit/s.

These results are theoretical and do not reflect what could be achieved in practise. Data rates experienced by end users depend not only on the distance between the customer premises and the exchange but also on home wiring and interference at the exchange, cabinet and in the home. In the real world there are different providers with different equipment sharing the exchange, and perhaps the cabinet, and therefore impacting performance. Nevertheless the real value of this study is to suggest an upper limit, given all technical progress possible, of 50Mbits, with fibre to the cabinet.