US 2026/0074792 A1Published application

Low complexity and low latency implementation for cellular fronthauling

AssigneeMicrosoft Technology Licensing, LLC

InventorArsalan SALJOGHEI

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Abstract

Systems and methods provide for a low complexity and low latency implementation for cellular fronthauling. At a baseband unit (“BBU”), data packets received from a data network are converted into analog data signals, which are in turn converted into analog optical signals that are optically amplified and sent over a hollow core fiber (“HCF”)-based fronthaul link(s) to a remote radio unit(s) (“RRU(s)”). At the RRU(s), the analog optical signals are converted into analog data signals that are sent over the air as radio frequency (“RF”) signals via an antenna(s). In some cases, the analog data signals are filtered and amplified prior to RF signal transmission. RF signals that are received, via antennas, at an RRU are conversely filtered and converted into analog optical signals, transmitted over the HCF-based fronthaul link(s) to the BBU, where the analog optical signals are converted into data packets for transmission over the data network.

Claims20

Dependent claims

A system for implementing improved cellular fronthauling, the system comprising:

a baseband unit (“BBU”) comprising a BBU controller, a data network interface, a signal processing system, a first electrical to optical transducer, a first laser, a first optical amplifier, and a first multiplexer;
a first demultiplexer;
a plurality of remote radio units (“RRUs”) each comprising a RRU controller, a first photodetector, a first optical to electrical transducer, and a first antenna;
and
a plurality of hollow core fiber (“HCF”)-based fronthaul links each established between the first multiplexer and the first demultiplexer;
wherein the BBU performs first operations comprising:
receiving, by the BBU controller and using the data network interface, a first data packet for transmission to one of the plurality of RRUs for radio frequency (“RF”) transmission;
determining, by the BBU controller, which RRU among the plurality of RRUs to send the first data packet;
routing, by the BBU controller, the first data packet to the signal processing system, based on the determined RRU to send the first data packet;
converting, by the signal processing system, the first data packet from digital data into a first analog data signal;
converting, by the first electrical to optical transducer, the first analog data signal into a first optical control signal;
generating, by the first laser, a first optical data signal based on the first optical control signal;
causing, by the first optical amplifier, amplification of the first optical data signal to produce a first amplified optical data signal;
and
sending the first amplified optical data signal to the determined RRU via the first multiplexer, over a corresponding HCF fronthaul link among the plurality of HCF-based fronthaul links, and via the first demultiplexer;
wherein each RRU performs second operations comprising:
receiving, by the first photodetector and from the first demultiplexer, the first amplified optical data signal;
converting, by the first optical to electrical transducer, the first amplified optical data signal into a second analog data signal;
and
sending, by the RRU controller and over the first antenna, a first RF signal based on the second analog data signal.

17 more elements

A computer-implemented method for implementing improved cellular fronthauling, the method comprising:

converting, by a baseband unit (“BBU”) controller at a BBU, a first data packet into a first analog data signal
converting, by a first electrical to optical transducer at the BBU, the first analog data signal into a first optical data signal;
causing, by a first optical amplifier at the BBU, amplification of the first optical data signal to produce a first amplified optical data signal;
sending the first amplified optical data signal to a remote radio unit (“RRU”) via a first multiplexer, over a hollow core fiber (“HCF”)-based fronthaul link, and via a first demultiplexer;
receiving, by a first photodetector at the RRU, the first amplified optical data signal;
converting, by a first optical to electrical transducer at the RRU, the first amplified optical data signal into a second analog data signal;
and
sending, by an RRU controller and over a first antenna at the RRU, a first radio frequency (“RF”) signal based on the second analog data signal.

5 more elements

A system, comprising:

a plurality of remote radio units (“RRUs”) each comprising a RRU controller, an optical amplifier, a laser, an electrical to optical transducer, and an antenna;
a plurality of multiplexers;
a baseband unit (“BBU”) comprising a BBU controller, a data network interface, a plurality of signal processing systems, a plurality of optical to electrical transducers, a plurality of photodetectors, and a plurality of demultiplexers;
and
a plurality of hollow core fiber (“HCF”)-based fronthaul links each established between one of the plurality of multiplexers and one of the plurality of demultiplexers;
wherein a first RRU among the plurality of RRUs performs first operations comprising:
receiving, by the antenna, a first radio frequency (“RF”) signal;
converting, by the RRU controller, the first RF signal into a first analog data signal;
converting, by the electrical to optical transducer, the first analog data signal into a first optical control signal;
generating, by the laser, a first optical data signal based on the first optical control signal;
causing, by the optical amplifier, amplification of the first optical data signal to produce a first amplified optical data signal;
and
sending the first amplified optical data signal to the BBU via a multiplexer among the plurality of multiplexers, over an HCF fronthaul link among the plurality of HCF-based fronthaul links, and via a demultiplexer among the plurality of demultiplexers;
wherein the BBU performs second operations comprising:
receiving, by a photodetector among the plurality of photodetectors and from the demultiplexer, the first amplified optical data signal;
converting, by an optical to electrical transducer among the plurality of optical to electrical transducers, the first amplified optical data signal into a second analog data signal;
converting, by a signal processing system among the plurality of signal processing systems, the second analog data signal into a first data packet;
and
sending, by the BBU controller and via the data network interface, the first data packet through a data network.

16 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/827,372Filed 6 Sep 2024
Published: 12 Mar 2026
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

H04B 10/25754
Distribution optical network, e.g. between a base station and a plurality of remote units: star network topology
H04B 10/25759
Between a central unit and a single remote unit by means of an optical fibre: details of the reception of RF signal or the optical conversion…
H04L 7/0008
Arrangements for synchronising receiver with transmitter: synchronisation information channels, e.g. clock distribution lines
H04W 88/085
Access point devices: access point devices with remote components