Which frequency band does the Iridium system use for telephone and messaging services?

The Iridium system, which is a satellite communications network designed for mobile telephony and data services, operates in the 1616 - 1626 MHz frequency band. This frequency range is specifically allocated for mobile satellite services, allowing the Iridium satellites to provide global voice and data communications capabilities across remote areas where traditional cellular networks are unavailable or unreliable.

This frequency band is essential for the system's functionality as it allows for effective transmission and reception of signals between the satellites and users' devices on the ground, ensuring that communications can take place without significant barriers or interruptions. The selected frequencies are part of a broader allocation for satellite communications, which enables devices to connect to the Iridium network effectively.

The other frequency ranges listed are associated with different communication services or systems. For instance, the 1492 - 1502 MHz band is typically used for other mobile applications, while the 1710 - 1755 MHz and 1850 - 1990 MHz bands are primarily allocated for terrestrial mobile services, such as LTE networks. Thus, they are not suited for the satellite communication functionalities that the Iridium system provides.