Low-Jitter Packet Scheduling Over Ethernet Switches
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current systems for low-jitter communication in packet-switched networks, particularly in wireless communication systems, face challenges in meeting tight jitter and high-speed requirements without the expense of dedicated optical links, and existing solutions do not adequately address the need for efficient alternatives.
Innovation Solution
A network communication system with a network controller that synchronizes data sources and switches to a common clock, maintaining records of transmission delays to optimize packet paths and schedules, ensuring low jitter and delay through precise timing and scheduling of packet transmission across the network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical links are used for low-jitter communication, then jitter bounds are satisfied, but cost increases and availability decreases
Solution Approach 1:
The patent replaces expensive optical links with standard Ethernet packet-switched network infrastructure that is widely available and cost-effective. By using scheduled packet transmission over conventional networks, the system achieves low-jitter performance without requiring costly dedicated optical connections.
Solution Approach 2:
The patent transforms the communication approach by changing from continuous optical signaling to scheduled packet transmission. By implementing precise departure time schedules and using time synchronization protocols, the system achieves deterministic low-jitter performance over packet-switched networks, fundamentally changing the operational parameters of the communication system.
2Reliability
If dedicated Ethernet connections are used for CPRI-over-Ethernet, then jitter and speed requirements are met, but network flexibility and sharing capability are reduced
Solution Approach 1:
The patent enables standard Ethernet switches and packet-switched networks to serve multiple functions simultaneously. The scheduled packet transmission mechanism allows the same network infrastructure to handle both time-sensitive CPRI traffic and general data traffic, eliminating the need for dedicated separate connections for each function.
Solution Approach 2:
The patent implements preliminary scheduling of packet departure times at network ingress points. By pre-calculating and communicating schedules to all network nodes before transmission begins, the system reserves time slots for critical traffic without requiring dedicated physical connections, thereby maintaining network flexibility while meeting jitter requirements.
3Ease of manufacture
If packet switching is used for network communication, then cost and availability improve, but jitter and delay control worsen
Solution Approach 1:
The patent implements periodic scheduled transmission of packets with predetermined departure times at each network node. This periodic scheduling mechanism transforms the inherently variable packet-switched network into a deterministic system where packets are transmitted at regular, pre-calculated intervals, ensuring consistent jitter and delay performance.
Solution Approach 2:
The patent employs network controllers that maintain records of actual transmission delays and use this feedback information to optimize packet schedules. By continuously monitoring network conditions and adjusting schedules based on measured performance, the system compensates for network variability and maintains strict jitter and delay bounds.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
There is disclosed a network communication system that includes data sources and of switches. Each of the data sources and switches is interconnected by a packet-switched network, and is synchronized to a common clock. The system also includes a network controller that maintains records of network characteristics including a transmission delay for each of the data sources and switches, and a transmission delay for links in the packet-switched network. The network controller processes the network characteristics to generate, for each of a plurality of packets of a given type of traffic: a path from a particular data source, and through at least one particular switch, and a schedule of departure times at each of the particular data source and the at least one particular switch. The path and the schedule are optimized to meet jitter requirements for the given type of traffic.