TDM Packet Transport Latency Management via Timestamp Discard
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current 5G Radio Access Networks face challenges in managing latency and jitter due to inefficient bandwidth usage in CPRI technology, which is not suitable for the stringent requirements of 5G fronthaul, leading to complex and costly network designs.
Innovation Solution
A method and apparatus that manage packet transport over TDM links by using time-stamps to identify and discard blocks exceeding maximum allowed latency, preventing delayed data from contributing to network congestion and optimizing queue processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If CPRI technology is used for 5G fronthaul, then bandwidth efficiency is improved, but latency and jitter requirements cannot be met
Solution Approach 1:
The patent segments packets into fixed-size blocks for TDM transmission, with each block containing a portion of the packet data and timing information. This segmentation enables precise latency control and tracking of individual packet components through the network, resolving the contradiction between bandwidth efficiency and latency requirements.
Solution Approach 2:
The patent applies preliminary action by inserting time-stamps and sequence numbers into packet blocks before transmission. This pre-marking enables the receiving end to identify and discard delayed blocks without requiring complex real-time analysis, thus maintaining low latency while achieving efficient bandwidth utilization.
2Loss of time
If TDM circuit switching is used, then latency is reduced, but fractional throughput and statistical multiplexing are not allowed
Solution Approach 1:
The patent creates a universal block structure that can carry any packet data while maintaining TDM timing characteristics. Each block is a self-contained unit that can be independently transmitted and tracked, allowing the system to provide both the low latency of TDM and the flexibility of packet switching for fractional throughput requirements.
3Loss of time
If networks are designed for worst-case scenario latency reduction, then latency requirements are met, but device complexity and cost increase
Solution Approach 1:
The patent implements self-service by embedding timing information directly within each packet block. Each block carries its own time-stamp and sequence number, enabling autonomous identification and handling at the receiving end without requiring complex centralized control or sophisticated scheduling algorithms, thus reducing device complexity while meeting latency requirements.
4Reliability
If delayed packets are not discarded, then packet integrity is maintained, but network congestion increases
Solution Approach 1:
The patent extracts delayed blocks from the transmission stream by identifying them through time-stamp comparison and discarding only the exceeded blocks while maintaining other blocks. This selective extraction preserves packet integrity for non-delayed portions while removing congestion-causing delayed data, balancing reliability and productivity.
Data Source
AI summary
A method of managing transport of packets transmitted over a time division multiplexed, TDM, link in a network. The method performed at a second network node comprises: receiving (102) blocks of data from a first network node. Data from one packet is received in a plurality of blocks and a first block from a packet has a time-stamp indicating arrival time of the packet at the first network node. The blocks are multiplexed for transmission over the TDM link. The method also comprises: queuing (106) the received blocks and if a block from the top of the queue (108, 110) has a time-stamp (110—yes) and a maximum allowed latency has been exceeded (112) the method discards (116) blocks containing data from the same packet as the block with said time-stamp if there is at least one block containing data from another packet in the queue (114—yes). An apparatus is also disclosed.