Fronthaul interface for use with a cloud radio access network

Patent metadata

Field	Value
Publication number	US-11838748-B2
Application number	US-202016918715-A
Country	US
Kind code	B2
Filing date	Jul 1, 2020
Priority date	Jul 2, 2019
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

A C-RAN includes a plurality of remote units; and a central unit communicatively coupled to the remote units via a fronthaul network. The central unit is configured to determine sets of data to be sent to respective subsets of remote units across the fronthaul network. The central unit is also configured to determine a mapping of each of the sets of data to a respective one of the subsets of remote units. The central unit is also configured to, for each of the sets of data, if at least one of the multicast groups wholly contains the respective subset of remote units mapped to that set of data, transmit that set of data to the respective subset of remote units over the fronthaul network by multicasting that set of data to the multicast group that best matches the respective subset of remote units mapped to that set of data.

First claim

The invention claimed is:

1. A cloud radio access network (C-RAN), comprising:
a plurality of remote units in a cell, each being configured to use a respective at least one antenna to exchange radio frequency signals with at least one user equipment (UE);
a centralized unit comprising at least one processor and communicatively coupled to the plurality of remote units via a fronthaul network, wherein the fronthaul network is configured to implement a plurality of multicast groups, each of the plurality of multicast groups including a respective group of the plurality of remote units, the centralized unit being configured to:
determine each of a plurality of sets of data to be sent across the fronthaul network to a respective corresponding subset of the plurality of remote units in the cell, wherein one of the plurality of sets of data is different than another one of the plurality of sets of data;
determine a mapping of each of the plurality of sets of data to the corresponding subset of the plurality of remote units; and
for each of the plurality of sets of data, if at least one of the plurality of multicast groups wholly contains the corresponding subset of the plurality of remote units mapped to that set of data, transmit that set of data to the corresponding subset of the plurality of remote units over the fronthaul network by multicasting that set of data to a multicast group of the plurality of multicast groups that best matches the corresponding subset of the plurality of remote units mapped to that set of data;
wherein an updated plurality of multicast groups is periodically defined based on at least locations of the at least one user equipment and at least locations of one or more of the plurality of remote units used to serve the at least one user equipment.

2. The C-RAN of claim 1 , wherein, for each of the plurality of sets of data, the multicast group of the plurality of multicast groups that best matches the corresponding subset of the plurality of remote units mapped to that set of data comprises one of the at least one of the plurality of multicast groups that wholly contains the corresponding subset of the plurality of remote units mapped to that set of data and that includes a least total number of the plurality of remote units.

3. The C-RAN of claim 1 , wherein the centralized unit is a Distributed Unit (DU) configured to operate in a Third Generation Partnership Project (3GPP) Fifth Generation communication system.

4. The C-RAN of claim 1 , wherein the centralized unit is a baseband controller configured to operate in a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) communication system.

5. The C-RAN of claim 1 , wherein the centralized unit is configured to:
add a respective indicator, based on the mapping, to each of the plurality of sets of data, wherein the respective indicator indicates each of the plurality of remote units that the corresponding set of data is intended for.

6. The C-RAN of claim 5 , wherein the respective indicator is a respective bitmask comprising a plurality of bit positions, where each of the bit positions corresponds to a respective one of the plurality of the remote units.

7. The C-RAN of claim 5 , wherein the centralized unit is configured to:
for each of the plurality of sets of data, if none of the plurality of multicast groups matches the corresponding subset of the plurality of remote units mapped to that set of data, transmit that set of data to the corresponding subset of the plurality of remote units over the fronthaul network by broadcasting that set of data.

8. The C-RAN of claim 1 , wherein the C-RAN is configured so that:
an initial plurality of multicast groups is defined and the fronthaul network is configured to implement the initial plurality of multicast groups; and
periodically, the updated plurality of multicast groups is defined and the fronthaul network is configured to implement the updated plurality of multicast groups.

9. The C-RAN of claim 8 , wherein the C-RAN is configured so that each updated plurality of multicast groups is further defined based on previous fronthaul traffic flows.

10. The C-RAN of claim 9 , wherein the locations of the user equipment and the plurality of remote units used to serve the user equipment are determined by one or more of:
Sounding Reference Signal (SRS), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), and/or Physical Random Access Channel (PRACH) uplink measurements made at each of the plurality of remote units;
preferred beam information that is determined by the user equipment; and
Channel State Information Reference Signal (CSI-RS) measurement reports received from the user equipment.

11. The C-RAN of claim 8 , further comprising a management system, wherein:
the centralized unit is configured to define the initial plurality of multicast groups and the updated plurality of multicast groups, and inform one or more of the management system and the plurality of remote units about the defined initial plurality of multicast groups and the updated plurality of multicast groups, and cause the fronthaul network to implement the defined initial plurality of multicast groups and the updated plurality of multicast groups; or
the management system is configured to define the initial plurality of multicast groups and the updated plurality of multicast groups, and inform one or more of the centralized unit and the plurality of remote units about the defined initial plurality of multicast groups and the updated plurality of multicast groups, and cause the fronthaul network to implement the defined initial plurality of multicast groups and the updated plurality of multicast groups.

12. The C-RAN of claim 11 , wherein management-plane (M-plane) communications are used to do at least one of:
the informing one or more of the management system, centralized unit, and the plurality of remote units about the defined initial plurality of multicast groups and the updated plurality of multicast groups; and
the causing the fronthaul network to implement the defined initial plurality of multicast groups and the updated plurality of multicast groups.

13. The C-RAN of claim 12 , wherein the M-plane communications comprise Open Radio Access Network (O-RAN) M-plane communications.

14. A method performed by a centralized unit in a cloud radio access network (C-RAN) that also comprises a plurality of remote units in a cell, each being configured to exchange radio frequency signals with at least one user equipment (UE), the centralized unit communicatively coupled to the plurality of remote units via a fronthaul network, wherein the fronthaul network is configured to implement a plurality of multicast groups, each of the plurality of multicast groups including a respective group of the plurality of remote units, the method comprising:
determining each of a plurality of sets of data to be sent across the fronthaul network to a corresponding subset of the plurality of remote units in the cell, wherein one of the plurality of sets of data is different than another one of the plurality of sets of data;
determining a mapping of each of the plurality of sets of data to the corresponding subset of the plurality of remote units; and
for each of the plurality of sets of data, if at least one of the plurality of multicast groups matches the corresponding subset of the plurality of remote units mapped to that set of data, transmitting that set of data to the corresponding subset of the plurality of remote units over the fronthaul network by multicasting that set of data to a multicast group of the pluralit

Assignees

• Commscope Technologies Llc

Inventors

• Raghothaman Balaji B
• Salahuddeen Irfaan Ahamed
• Barabell Arthur J
• Armao Calogero

Classifications

• H04W40/02 Primary

  Communication route or path selection, e.g. power-based or shortest path routing · CPC title

• H04L5/0044

  Allocation of payload; Allocation of data channels, e.g. PDSCH or PUSCH · CPC title

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04L12/1845

  broadcast or multicast in a specific location, e.g. geocast (protocols for adapting network applications to user terminal location H04L67/52; services specially adapted for wireless communication networks making use of the location of users or terminals H04W4/02) · CPC title

• H04L69/164

  Adaptation or special uses of UDP protocol · CPC title