Transportation communications needs antennas with efficient patterning for mass transit systems and railway networks. Antenna patterning, the graphical representation of antenna radiation as a function of space, describes the direction in which antennas send or receive radio waves. Wireless signals travel in multiple directions, but physical obstructions such as bridges, tunnels, buildings, and poles can disturb line-of-sight (LOS) paths to and from buses, subways, freight trains, waysides, and base stations.
For standard antennas that depend upon LOS communications, physical obstructions are a problem even when antennas are more powerful in a specific direction. Weather conditions can also cause signal reflectivity and multi-path distortions. Transit antennas can receive reflected signals from multiple angles, multiple times, but not without challenges for reliable communications. Multi-path, the arrival of reflected signals, can cause significant variations in the received signal and add to or subtract from it.
Radiation Patterns and Multi-Polarization
Manufacturers typically represent antenna patterning in horizontal and vertical planes. In turn, these two circular planes can have directional, bidirectional, hemispheric, omnidirectional, or full radiation patterns. Antennas with directional radiation patterns send or receive greater power in one direction, or lobe. Bidirectional antennas radiate greater power in two directions, or lobes, instead. Often, these lobes look like the propellers on an airplane.
Hemispheric antennas radiate greater power in half of the plane, and omnidirectional antennas radiate power equally in all directions. For antennas with a full radiation pattern, the shape fills most but not all of the horizontal or vertical plane. Each of these patterns is used in transportation communications but patterning alone does not determine antenna reliability. That’s why mass transit systems and rail networks are choosing multi-polarized antennas for wireless communications under NLOS conditions.
MP-TL TransitLink™: Bidirectional Antennas and More
MP-TL TransitLink™ antennas from MP Antenna provide effective patterning and are multi-polarized for improved coverage regardless of orientation. These Made in USA antennas also support greater network throughput speeds, a key consideration for demanding applications such as positive traction control (PTC), live video streaming, and secure communications. TransitLink™ antennas are available for a variety of frequency bands and include bi-directional antennas as well as products with other antenna patterns.
Read more about MP antennas for transportation communications, or contact us with questions.