Cable model for high speed data transmission

Looking at cable models, an interesting expression was found. Though approximate and using " typical cable parameters" it can be used to at least get a feel for the challenges of transmitting high speed data down a UTP cable. The expression is: f3db = 2.25E4/(d*d). Here d is the length of the cable in Km. From this an interesting conclusion can be drawn. The bandwidth of this "typical" cable of length 100 Meters is only 2.25 Mhz. At the other extreme, a 1 Meter cable will have a 22.5 GHz of bandwidth. A 10 Meter cable will have a bandwidth of 225 Mhz and so on. So if we need to transmit data at high MHz or low GHz speeds, on a longer cable, then there is no option except to design and use an equalizer. This is of course a whole new ball game with many issues. From an initial assessment it appears that an analog equalizer is the best option here. The design is understandable and the technology is available to implement it in a reasonable amount of cost, time and space on an ASIC as needed.