Microwave links are communication systems that use radio frequency (RF) signals in the microwave frequency range to transmit and receive information. They can be terrestrial (over land) or satellite-based. Here are some key points about microwave links:
- Frequency Range: Microwave links typically operate in the frequency range between 1 GHz and 100 GHz. However, the most commonly used bands for terrestrial microwave links are between 6 GHz and 38 GHz.
- Point-to-Point Communication: Microwave links are primarily used for point-to-point communications. This means they connect two locations directly without any intermediate repeaters or nodes.
- Applications: They’re widely used for long-distance telephone communication, television and radio broadcasting, internet connectivity, and private business networks. They can also play a critical role in backhauling data from cellular towers to the core network.
- Antenna and Line of Sight: Microwave communication requires a direct line of sight (LOS) between the transmitting and receiving antennas. This is because microwaves travel in straight lines and are affected by obstructions like buildings or mountains. Antennas are often placed on tall towers or elevated locations to ensure an uninterrupted path.
- High Bandwidth: Microwave links can offer high bandwidth, making them suitable for transmitting large amounts of data, voice, or video.
- Adverse Weather Impact: The performance of microwave links can be impacted by atmospheric conditions. For instance, rain can cause attenuation in the signal, especially at higher frequencies.
- Reliability: Modern microwave links are highly reliable. With advancements in technology, they can offer near 99.999% uptime, depending on the design and redundancy measures in place.
- Alternative to Fiber: In areas where it’s challenging or not cost-effective to lay fiber optic cables, microwave links can provide a fast and efficient alternative for high-speed data transmission.
- Satellite Communication: Microwave frequencies are also used for satellite communication, but this operates in slightly different bands and has unique considerations compared to terrestrial microwave communication.
- Hop Length: The distance between two microwave stations is called a hop. Depending on the frequency, power, antennas, and atmospheric conditions, a hop can range from a few kilometers to several tens of kilometers.
- Cost: Setting up microwave links can be cheaper and quicker than laying fiber, especially over challenging terrains or in areas where rights-of-way are hard to obtain.
In recent years, with the increasing demand for bandwidth and the widespread use of fiber optics, the role of terrestrial microwave links has evolved. While they might not be the primary choice for all applications, they remain crucial in specific scenarios where quick deployment or geographical challenges make them the most viable option.