Ship-to-shore long-distance wireless video data transmission communication for IP camera

One client sent his inquiry, he needs to transmit a video signal from an IP camera over the sea for around 15-25km. He was wondering if we have any solution for this.

To realize the long-distance wireless video data transmission solution of 15~25 kilometers, especially when the transmitter and IP camera are on a moving ship, the receiver and computer are on the shore, and the transmitter and receiver are basically at the same horizontal level, there are many challenges and difficulties.

Antenna height in Ship-to-shore long-distance wireless video data transmission

Because the earth is round and its surface has a curvature, when the distance exceeds 15 to 25 kilometers, the waves between the transmitter and the receiver can easily form obstacles to the line-of-sight transmission range, interfering to the wireless transmission of video and data.

Earth Curvature Calculation:
The minimum combined height of ship and shore antennas to overcome Earth curvature can be estimated using:

h=d²/12.75k(in meters)

• K: Effective Earth radius factor (typically 4/3 to account for atmospheric refraction).
• Example: For 25 km transmission, the total height required is:
• h=25²/12.75×1.33≈36.8 meters (combined for both ends).
• Thus, ship and shore antennas should each be elevated by 18–20 meters (adjust based on actual terrain).

Fresnel Zone Clearance:

To avoid signal blockage, ensure 60% of the Fresnel Zone radius is unobstructed:

r = 8.66√(d/f)

• d: Distance (km)
• f: Frequency (GHz)
  Example: For 1.4 GHz and 25 km, the Fresnel Zone radius is ~36 meters. Antenna height must accommodate this.

Through the calculation tool above, it can be deduced that if a transmission of 15 to 25 kilometers is required on the shore, the height of the receiving antenna on the shore must be at least 36 meters, which is equivalent to the height of a 10-story building. It can be set up on the top of a building or in an open area on the top of a mountain near the shore.

As long as the antenna height prerequisite is met, our wireless transmission equipment, whether it is one-way transmission or two-way transmission, can basically reach this transmission range.

We can recommend specific models based on the customer’s specific project requirements, such as the number of cameras, the amount of data, etc.