At first sight, a mobile network and a modern, optical fiber-rich, fixed line network have little in common. They might be seen as competitors. After all, we hear regular stories of consumers "cutting the cord" and meeting all their voice and basic data needs with their smartphones.
In fact, the opposite is true - the growth in data volumes that need to be transmitted quickly around the "mobile" core network cannot generally be met through mobile technologies.
Essentially, this means that the core of a mobile network is made up of fixed line, usually fiber, connections.
The anatomy of a wireless network
Before we look at how fiber and wireless networks complement each other, it is worth taking a step back to look at wireless technology overall. Mobile phones transmit and receive signals in the microwave portion of the electromagnetic spectrum, specifically in the region 872 to 960, 1710 to 1875 and 1920 to 2170 MHz in the UK. Just below that frequency range TV broadcasts are carried and at higher microwave frequencies radar, satellite communication, and specialized applications operate.
This means there is limited capacity for onwards transmission of mobile telephony or data over the electromagnetic spectrum, even if it were to be a technically efficient medium.