The demand for Internet bandwidth is set to double in two years and grow still further, according to a study carried out by the Institute of Advanced Telecommunications.The independent ‘Global Bandwidth’ study said that huge changes in network content and social behaviours will mean bandwidth demand exceeds 160 Tbits/s by 2010 â€“ an annual demand that exceeds the equivalent of the combined broadband network usage of the previous decade (1998-2008).Professor David Payne, the study's author, has calculated that increasing demands are not likely to lessen as the use of streaming online video and data services expands. He said: "Around the turn of the millennium, we used to talk about a bandwidth â€˜glut'. There was a lot of idle capacity. Networks now are being used in a way that few people foresaw, for example early take-up of personalised video, rather than broadcast television, dominating internet video services."But Payne found that, based on a range of service scenario models, demands for bandwidth will continue to put increasing pressure on existing network infrastructures and warned of the need for significant infrastructure investment. "By 2018, assuming that this capacity is made available by the operators, usage could grow to 40 to 100 times the levels seen in networks today," he said. "However it is difficult to see how operators can economically grow existing network architectures to meet this demand and further consideration of the types of networks and the technology deployed is required if they are to ensure profitability."