The actual demand of Internet services is increasing fast and the contents arebecoming heavier because of the higher demand of video and voice services as VoIP andHDTV. This fact is pushing the actual infrastructure to the limit and service providersare lead to invest in new technologies and new infrastructure. The solution seems to befound in the use of cable and fiber optics but while this technologies are capable ofoffering video and voice services they cannot offer the 3 services together (voice, videoand Internet access). Also the use of this technologies means that the whole actualinfrastructure need to be changed.Meanwhile this technologies are not ready, the solution is to improve theperformance of the exiting copper pair infrastructure and nowadays the technology thatdoes this better is VDSL which can provide up to 52 Mbps on a single cooper pair loop.Besides, VDSL, as other DSL technologies, is capable of providing Internet and voiceservices because it is compatible with POTS and ISDN and in addition, VDSL canprovide video services thanks to the higher throughput.To achieve this higher bit rates, VDSL uses the frequency range up to 30 MHz andDMT modulations as OFDM that divides the frequency spectrum into a number of tonesas FDM but with the particular characteristic that the tones are orthogonal providing avery limited intercarrier interference (ICI) and a better performance.Summed to VDSL, in the last years, the use of multiple transmitters andreceivers is revolutionizing telecommunications. MIMO systems has been proved to bea very useful tool to improve capacity in wireless communications by using severalantennas at the transmitter and the receiver side but it is also possible to use MIMO inwired communications and in particular in DSL transmissions. For example, using 4bonded lines it is possible to operate at more than 6 times the rate of a single line.In this paper we will combine the benefits of VDSL and MIMO technologies toimplement simulations of the capacity on a system composed of 8 lines transmittingtogether. The simulations have the purpose of seeing how the capacity of the system isaffected by internal and external phenomena as for example different kind ofinterferences. In the part “Simulations of the capacity” you will find differentsimulations of a binder of 8 lines using MIMO and VDSL with thermal noise and3external noise affecting as well as different power constraints. The external noise herecomes from a parallel transmission of another 8-line binder. There is also a simulationof a SISO system with an external noise coming from the parallel lines of the original 8-line binder.We have considered 2 scenarios for the different simulations: the fist one where weevaluate capacity with loops of different lengths and the second one where we evaluatecapacity for binders with different number of lines. The different simulations are:– Capacity under total power constraints with Additive White Gaussian Noise(AWGN).– Capacity under total power constraints with AWGN and external noise.– Capacity under per-modem total power constraints with AWGN and external noise.– Capacity under per-modem total power constraints and spectral mask constraintswith AWGN and external noise.– Capacity of a SISO system with AWGN and external noise (coming from theparallel lines).After evaluating each simulation separately there is a comparison of all them togetherwhere we are able to see their achievements and their behaviors.