Two-Stage Packet Scheduler for Delay-Critical Traffic

Solution Overview

Problem

Existing methods for scheduling transmission link capacity in packet-switched telecommunications systems fail to guarantee that delay-critical traffic is prioritized over non-delay-critical traffic, leading to unpredictable and unsatisfactory allocation of capacity between different traffic groups, such as those from customers A1 and A2.

Innovation Solution

Implementing a two-stage packet selection process using weighting-factor based scheduling, where Stage 1 identifies packets with the highest priority and Stage 2 selects using a weighting-factor method, ensuring consistent handling of sub-groups across priority levels, allowing delay-critical traffic to be scheduled before non-delay-critical traffic and ensuring fair capacity allocation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional weighting-factor based scheduling is used, then capacity is allocated according to weights, but delay-critical traffic is not guaranteed to be scheduled before non-delay-critical traffic

Engineering Contradiction:

Improvedelay guaranteeVSAvoidscheduling complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the packet group into sub-groups based on priority values, creating separate queues for different priority levels. This segmentation allows delay-critical packets to be processed in dedicated high-priority queues before lower-priority packets, ensuring delay guarantees while maintaining the weighting-factor based capacity allocation within each priority level.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary classification of packets into priority-based sub-groups before applying the weighting-factor based scheduling. By pre-separating delay-critical traffic into high-priority sub-groups, the system ensures these packets are scheduled first, while still allowing fair capacity allocation among packets of the same priority level using weighting factors.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If priority-based scheduling is implemented, then delay-critical traffic is prioritized, but fair capacity allocation between different traffic groups is compromised

Engineering Contradiction:

Improvedelay guaranteeVSAvoidcapacity allocation fairness

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies different scheduling qualities to different parts of the packet group. High-priority sub-groups containing delay-critical packets receive preferential treatment with guaranteed scheduling before lower-priority packets. Within each priority level, the weighting-factor based scheduling ensures fair capacity allocation according to assigned weights, thus achieving both delay guarantees and fairness.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent introduces a priority dimension in addition to the weighting factor dimension. Packets are first classified by priority value into separate sub-groups, then weighting factors are applied within each priority level. This multi-dimensional approach allows simultaneous achievement of delay-critical packet prioritization and fair capacity allocation among traffic groups.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Productivity

If capacity is shared between multiple customers, then network utilization is improved, but unpredictable allocation occurs when loading varies

Engineering Contradiction:

Improvenetwork utilizationVSAvoidcapacity allocation predictability

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent performs preliminary classification of packets into priority-based sub-groups before applying the weighting-factor based scheduling. By pre-separating delay-critical traffic into high-priority sub-groups, the system ensures these packets are scheduled first, while still allowing fair capacity allocation among packets of the same priority level using weighting factors.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent applies different scheduling qualities to different parts of the packet group. High-priority sub-groups containing delay-critical packets receive preferential treatment with guaranteed scheduling before lower-priority packets. Within each priority level, the weighting-factor based scheduling ensures fair capacity allocation according to assigned weights, thus achieving both delay guarantees and fairness.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS7826354B2Method preserving delay properties and an apparatus for scheduling transmission link capacity between packet switched telecommunications flows

Publication Date: 2010.11.02 CORIANT

AI summary

The invention relates to a method and apparatus for scheduling transmission-link capacity between packet switched telecommunications flows (L1, L2), in such a way that it is possible to ensure the scheduling of packets representing delay-critical traffic to the transmission link (S) before packets representing non-delay-critical traffic and, in addition, to achieve the desired division of the capacity of the transmission link (S) between different traffic groups. The invention is based on performing the selection in the scheduling in stages, as follows: 1) the packets with the highest priority among the packets being offered are sought and 2) from the sub-group obtained, a final selection is performed using a weighting-factor based scheduling method, in such a way that the same weighting-factor based scheduling process is used to handle the sub-groups representing different priority levels in the consecutive selection situations.