Which technique is often used to mitigate radio signal loss in urban areas?

Using repeaters is a well-established technique for mitigating radio signal loss in urban areas, where buildings and other obstacles can cause significant attenuation and multipath interference. Repeaters function by receiving a radio signal, amplifying it, and then retransmitting it. This helps to extend the coverage area and improve signal quality by allowing the signal to bypass obstacles that would otherwise obstruct or weaken it.

In urban environments, where physical structures can obstruct line-of-sight communication and contribute to signal degradation, repeaters are especially valuable. They can be strategically placed to ensure that there are fewer dead spots and that signals can be transmitted over longer distances without significant loss in quality. This is particularly important in dense urban settings where traditional signal propagation methods may be insufficient to maintain reliable communication.

In contrast, increasing the emission frequency may lead to a different nature of propagation, potentially enhancing or degrading signal performance depending on other factors, but it does not directly address the issue of loss due to urban obstructions. Reducing antennae size generally does not improve signal quality; in fact, smaller antennas may have lower gain and thus could worsen the situation. Restricting signal range would not solve the issues of signal loss—it would merely limit the operational capacity of the network.