Port communications need antennas that can send and receive reliable signals in multiple directions under non-line-of-sight (NLOS) conditions. Wireless signals don’t just travel in one direction, but some antennas are more powerful in a specific direction. That’s a problem when shipping containers and cranes are in the way and can prevent radio waves from reaching their target directly. Antennas can receive reflected signals from multiple angles, multiple times, but not without challenges for port communications.
Multi-path, the arrival of reflected signals, can cause significant variations in the received signal and add to or subtract from it. Phase cancellation, the failure of two signals of the same frequency to reach a receiving antenna at the same time, can also occur. That’s a problem for ships that need to communicate their operational status or arrival times, and shipping terminals that need to manage traffic and provide access to berths and equipment. The movement of ships, whether from waves or propulsion, also complicates communications since marine vessels are not fixed points in space.
Directional Antennas vs. Omnidirectional Antennas
Antenna patterning, the graphical representation of antenna radiation as a function of space, describes the shape or direction in which antennas send or receive radio waves. Directional antennas have a horizontal or vertical radiation pattern that is characterized by a main lobe in one direction. Omnidirectional antennas have a horizontal radiation pattern that is donut-shaped and a vertical radiation pattern that is hemispheric.
Directional antennas that radiate or receive greater power in specific directions can support increased performance under line-of-sight (LOS) conditions, but port communications are typically characterized by NLOS, multi-path, and moving targets (ships). That’s why omnidirectional antennas are typically used for port communications, both from shore-to-ship and ship-to-shore. When shipping container and cranes get in the way, omnidirectional antennas can send or receive signals from more than just one direction.
Port Wave™ Antennas for Port Communications
MP Antenna of Elyria, Ohio designs and manufactures multi-polarized antennas with both omnidirectional and directional radiation patterns. These Made in America antennas feature patented three-dimensional designs, built-in spatial diversity on every feed, and are tested under real-world conditions. MP’s Port Wave antennas are an especially good choice for marine environments because they have an impact-resistant radome that also resists sea water and fresh water.
To learn more MP Antenna’s solutions for port communications, contact us.