In a video interview with Nextivity CEO Michiel Lotter, EE World looks at the technology behind cellular repeaters that distribute signals over Ethernet cables before rebroadcasting.
If you watch the 5G TV ads for 5G coverage, every carrier will claim to have the best. That is, however, only for outdoor coverage but what about indoors? After all, we often hear that most cellular use is indoors.
That’s where cellular repeaters play a role. While some repeaters handle mmWave signals, 5G’s mid-band frequencies still don’t penetrate buildings quite as well as they do at lower frequencies. While some repeaters operate entirely wireless, what happens in large buildings with rooms where even repeated signals can’t reach?
If a building has Ethernet cables not used for an internal network, they distribute baseband cellular signals. Nextivity CEO Michiel Lotter explains how the company’s ASIC takes demodulated cellular signals from an RF transceiver IC, then sends baseband bits to remote transceivers that modulate and rebroadcast cellular signals. The figure shows a schematic of the system. The network unit (NU) connects to cellular networks using directional antennas, bringing the bits down to baseband for distribution to the coverage units (CUs) around the building. Although the baseband distribution uses Ethernet cables, it’s not at all based on IEEE 802.3.
In addition to discussing the system and ASIC, Lotter explains that even though Ethernet ICs generally handle signal integrity issues, problems can still arise. When that happens due to an excessively long cable (over 150 m) or a poor connection, Nextivity software will notify the user. Lotter also explains why the company has not (so far) chosen to add mmWave capabilities to its product line.