C-RAN Multicast Front-Haul Bandwidth Optimization
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Solution Overview
Problem
In centralized radio access networks (C-RAN), the current methods for communicating downlink user data over front-haul networks are inefficient, either leading to high bandwidth wastage due to broadcasting or increased bandwidth requirements at baseband units when using unicast addressing, as all radio points receive data regardless of need, or excessive bandwidth demands at baseband units when unicast is employed.
Innovation Solution
Implementing a multicast zone using multicast groups within the front-haul network, where downlink user data is transmitted to specific multicast groups corresponding to the simulcast zone of user equipment, minimizing bandwidth requirements at radio points while managing increased demands at the baseband unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If broadcast is used to communicate downlink user data to all radio points, then all radio points receive the data, but bandwidth requirements at radio points increase unnecessarily
Solution Approach 1:
The patent segments the set of radio points into multiple groups based on their simulcast zones. Instead of broadcasting to all radio points uniformly, the system creates distinct multicast groups where each group contains radio points that need to receive data for specific UEs. This segmentation allows targeted data delivery, reducing unnecessary bandwidth consumption at radio points that don't require the data.
Solution Approach 2:
The patent implements local quality by assigning different multicast group memberships to different radio points based on their specific simulcast zones. Each radio point receives only the multicast groups relevant to its assigned UEs, rather than all broadcast data. This creates localized data delivery optimized for each radio point's actual needs, reducing unnecessary bandwidth consumption.
2Loss of energy
If unicast addressing is used to send packets to individual radio points, then bandwidth requirements at radio points are minimized, but bandwidth requirements at baseband units increase
Solution Approach 1:
The patent merges multiple unicast transmissions into multicast transmissions. Instead of the baseband unit creating separate unicast packets for each radio point in a simulcast zone, the system combines these into a single multicast packet that is delivered to all radio points in the group simultaneously. This merging reduces the total bandwidth consumption at the baseband unit while maintaining efficient delivery to individual radio points.
Solution Approach 2:
The patent creates multicast groups that serve multiple functions: a single multicast transmission serves multiple radio points simultaneously, and the same multicast infrastructure supports multiple UEs with different simulcast zones. This multi-functionality allows the baseband unit to reduce its bandwidth requirements by leveraging the shared nature of multicast traffic.
3Loss of energy
If multicast zones are formed to transmit data to specific radio points, then bandwidth requirements at radio points are reduced, but network complexity increases
Solution Approach 1:
The patent performs preliminary action by pre-configuring multicast groups and their associated radio points before data transmission occurs. The baseband unit determines simulcast zones and forms appropriate multicast groups in advance, so that when data needs to be transmitted, the multicast infrastructure is already in place and ready for immediate use. This preliminary configuration simplifies the actual data transmission process.
Solution Approach 2:
The patent implements feedback mechanisms where the baseband unit monitors and tracks which radio points are members of which multicast groups, and adjusts multicast group assignments based on current UE locations and simulcast zone requirements. This feedback allows the system to dynamically optimize multicast configuration without requiring complex manual setup, reducing overall system complexity.
Data Source
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AI summary
This disclosure is directed to techniques for transmitting downlink user data over a front haul in a C-RAN using multicast addressing and a system comprises a controller and a plurality of radio points, wherein the controller is configured to: determine a simulcast zone for a UE, the simulcast zone comprising a plurality of radio points from which downlink user data is wirelessly communicated to the UE; attempt to form a multicast zone for the simulcast zone, the multicast zone comprising a plurality of multicast groups implemented by the front haul; and if the multicast zone is successfully formed, transmit downlink user data for the UE to the radio points in the simulcast zone over the front haul by transmitting the downlink user data to the multicast groups.