Until recently the WISP was an exclusive technology that was only available in rural areas without cable or DSL service. They make use of a T-carrier with a high capacity to transmit a signal from a high elevation, like water towers. Nowadays, people install a small dish on the roof of their home and then point it towards the wireless transmitter. Line-of-sight is required in the 2.4 and 5.GHz bands. The 900 MHz band has better non-line-of-sight performance.