Caltrain Wi-Fi installation

Caltrain/Amtrak employees mount antennas on Caltrain cars at railyard in San Francisco.

A signal bridge near the Millbrae, Calif., station provides a location for a single radio/antenna facing south. Signal bridges make excellent antenna sites because of their commanding view of the tracks.

Near the Millbrae, Calif., station, a worker mounts a transceiver and antenna to the signal bridge.

Workers erect a new pole near the Belmont station to mount north- and south-facing antennas.

Caltrain Bullet train stopped at San Carlos, Calif., station.

At the San Carlos, Calif., station, workers install antennas.

At the San Carlos, Calif., station, north- and south-facing antennas communicate to the train, while a third antenna provides point-to-point backhaul.

Along the Caltrain right of way near Palo Alto, Calif., workers dig a cable trench to the base station location.