Fronthaul Synchronization via TDD Periodic Scheduling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Packet Delay Variation (PDV) in packet-based fronthaul networks affects synchronization accuracy, particularly in TDD radio transmissions, due to varying network latency and queuing effects, which can lead to timing alignment errors that exceed stringent requirements.
Innovation Solution
The method involves obtaining information on uplink and downlink time periods occupied by TDD radio transmissions and scheduling packet-based synchronization messages accordingly, taking advantage of the periodic utilization pattern of TDD systems to minimize PDV.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If packet-based synchronization protocols are used in fronthaul networks, then scalability is improved, but synchronization accuracy deteriorates due to packet delay variation
Solution Approach 1:
The patent applies preliminary action by proactively scheduling synchronization messages during predetermined time periods when network traffic is expected to be lower. The network entity obtains information about uplink and downlink time periods occupied by TDD radio transmissions and schedules synchronization messages accordingly, before the actual synchronization occurs. This anticipatory scheduling reduces packet delay variation and improves synchronization accuracy while maintaining scalability.
2Productivity
If TDD radio transmissions are implemented, then spectral efficiency is improved, but timing alignment becomes more difficult due to uplink-downlink switching
Solution Approach 1:
The patent applies local quality by treating uplink and downlink time periods differently in the scheduling process. The network entity obtains separate information about uplink and downlink time periods occupied by TDD radio transmissions and schedules synchronization messages specifically for each direction during appropriate time windows. This differentiated approach accounts for the directional nature of TDD transmissions and simplifies timing alignment while maintaining spectral efficiency.
3Adaptability or versatility
If packet-based fronthaul network is used, then network flexibility is improved, but latency becomes variable affecting synchronization
Solution Approach 1:
The patent applies periodic action by scheduling synchronization messages during regular, predictable time periods that coincide with lower network activity phases in the TDD cycle. The network entity utilizes the periodic nature of TDD radio transmissions to identify optimal scheduling windows, creating a rhythmic pattern where synchronization occurs periodically during uplink or downlink periods when packet delay variation is minimized. This periodic scheduling maintains network flexibility while reducing variable latency.
Data Source
AI summary
A method performed by a network entity is provided. The method comprises obtaining information indicating uplink, UL, and downlink, DL, time periods in the packet-based fronthaul network occupied by Time-Division Duplex, TDD, radio transmissions transmitted and/or received by the one or more second fronthaul network units over its radio interface. The method further comprises scheduling packet-based synchronization messages between at least the one or more first fronthaul network units and the one or more second fronthaul network units over the packet-based fronthaul network based on the obtained information. A network entity is also provided, as well as, computer programs and carriers.