Which of the following is an example of increased spectral efficiency in public safety land mobile radio?

The correct answer pertains to the development of interoperability standards, which significantly enhances spectral efficiency in public safety land mobile radio systems. Increased spectral efficiency refers to the optimal use of available radio frequency spectrum to maximize communication capacity and minimize interference.

Interoperability standards allow various communication systems to work together seamlessly, enabling different agencies and organizations to communicate effectively and share channels. This reduces the need for multiple dedicated frequencies for each agency, leading to more efficient use of the available spectrum. By standardizing protocols and technologies, it facilitates better coordination and response in times of emergency, ultimately enabling more users to share the same frequency resources without degradation in communication quality.

The other options do not directly contribute to increased spectral efficiency. Using analog signals limits the data capacity and spectral efficiency compared to digital alternatives. Reducing radio equipment costs may improve budget efficiency but does not inherently affect how well the spectrum is utilized. Similarly, limiting user access to frequencies can lead to underutilization of the spectrum rather than its more efficient use. Thus, the development of interoperability standards is the clear choice for supporting increased spectral efficiency within public safety communications.