This paper investigates on the channel capacity estimation in millimeter-wave bands of ultra-wideband transmission for inside metro carriage scenarios. For the simulations, a high-precision 3D model was used where three Transmitters (TXs) antennas were placed at the top of the carriage and multiple Receiver (RX) antennas along the carriage were placed at heights of 0.6m and 1.5m. To estimate large-scale fading in 28, 36 and 72 GHz frequency bands, four path loss models were used and evaluated: 3GPP, CI, CIF and ABG. These models have been implemented to estimate the interference between the other TXs and to calculate the Signal-to-Interference-plus-Noise Ratio (SINR) and received power for each user. This evaluation shows that Millimeter Wave (mmW) can achieve extreme bandwidth using a Single Input Single Output (SISO) link ranging from 120 Mbps to 3 Gbps for the bands under study.