Cellular Buffer Watermark Control for Router Decongestion

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Solution Overview

Problem

Current cellular interface management in network environments faces challenges such as system congestion, dropped packets, and overloaded router resources due to varying traffic flows across cellular interfaces, which are difficult to manage effectively, especially under dynamic environmental and user conditions.

Innovation Solution

A method and system that dynamically adjust the bandwidth of cellular interfaces based on predicted average throughput, using techniques like determining throughput per resource block and instantaneous throughput, and configuring Quality of Service (QoS) policies to ensure optimal bandwidth allocation and load balancing across multiple interfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If cellular interface bandwidth is increased to handle varying traffic flows, then system congestion and packet loss are reduced, but router resources become overloaded and device complexity increases

Engineering Contradiction:
Improvetraffic flow reliabilityVSAvoidrouter resource load
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent implements dynamic bandwidth adjustment by continuously monitoring throughput metrics (instantaneous throughput, predicted average throughput) and adapting cellular interface bandwidth allocations in real-time. This dynamic approach allows the system to scale resources according to actual traffic demands rather than maintaining fixed high bandwidth, thereby improving reliability during peak loads while conserving router resources during lower utilization periods.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes operational parameters by adjusting bandwidth allocations based on calculated throughput metrics. Specifically, it monitors instantaneous throughput and predicted average throughput, then modifies cellular interface bandwidth parameters dynamically. This parameter adaptation resolves the contradiction by matching resource allocation to actual performance needs rather than static configurations.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If bandwidth is dynamically adjusted based on throughput metrics, then resource utilization is optimized, but measurement precision and monitoring complexity increase

Engineering Contradiction:
Improvebandwidth utilization efficiencyVSAvoidthroughput measurement accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms by continuously monitoring throughput metrics (instantaneous throughput, predicted average throughput) and using this information to adjust bandwidth allocations. The system establishes performance benchmarks and compares actual throughput against these benchmarks, creating a closed-loop control system that refines measurements over time and reduces monitoring complexity through pattern recognition and predictive algorithms.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system performs preliminary actions by establishing predicted average throughput benchmarks before actual bandwidth allocation decisions are made. These predictive measurements and pre-calculated throughput expectations serve as reference points that simplify real-time decision-making, reducing the complexity of on-the-fly measurements while maintaining high utilization efficiency.

Inventive Principle:
Principle #10Preliminary action

3Reliability

If QoS policies are configured for multiple cellular interfaces, then service quality for critical applications is ensured, but device complexity and configuration difficulty increase

Engineering Contradiction:
Improvecritical application service qualityVSAvoidQoS configuration simplicity
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent automatically adjusts QoS parameters based on monitored throughput metrics and traffic patterns. Rather than requiring manual configuration of complex QoS policies, the system dynamically changes bandwidth allocation parameters and service quality settings according to actual performance data, critical application requirements, and current network conditions, thereby ensuring service quality while simplifying operation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system provides self-service by automatically configuring and adjusting QoS policies based on monitored traffic flows and performance metrics. The router autonomously identifies critical applications, calculates appropriate bandwidth allocations, and implements QoS settings without requiring manual intervention or complex configuration procedures, thus ensuring service quality while maintaining ease of operation.

Inventive Principle:
Principle #25Self-service

4Loss of time

If bandwidth allocation is optimized for current traffic conditions, then latency is reduced, but adaptability to changing environmental conditions decreases

Engineering Contradiction:
Improvepacket latencyVSAvoidenvironmental condition adaptability
Core Design Contradiction:
Loss of timeVSAdaptability or versatility

Solution Approach 1:

The patent implements continuous dynamic monitoring and adjustment of bandwidth allocations based on real-time throughput metrics and changing environmental conditions. The system adapts to varying signal quality, user demands, and network conditions by continuously recalculating predicted average throughput and adjusting allocations accordingly, thereby reducing latency while maintaining high adaptability to environmental changes.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system uses feedback loops to continuously monitor traffic conditions, signal quality, and throughput performance, then adjusts bandwidth allocations in response to these changing conditions. This feedback mechanism ensures low latency by optimizing for current conditions while simultaneously maintaining adaptability through continuous adjustment based on environmental variables and performance metrics.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3355659B1System and method for buffer management for cellular interfaces in a network environment
Publication Date: 2020.03.04 CISCO TECHNOLOGY INC
  • EP3355659B1 patent drawingFigure 1A
  • EP3355659B1 patent drawingFigure 1B~2
  • EP3355659B1 patent drawingFigure 3~4

AI summary

Cellular modem 150 includes transmitter 152 and receiver 154. Transmitter 152 receives uplink traffic (e.g., IP packets) via host router interconnect 112, which are to be transmitted to eNodeB 132, and receiver 154 receives downlink traffic from eNodeB 132. Transmitter 152 includes a Packet Data Convergence Protocol (PDCP) layer 710, a Radio Link Control (RLC) layer 712, a Media Access Control (MAC) layer 714 and a physical (PHY) layer 716. Each layer operates on IP packets that are to be transmitted. MAC layer 714 additionally includes MAC control logic 720 and a buffer 722, which provide for buffering packets that are to be scheduled for transmission via PHY layer 716. Buffer 722 provides buffering for uplink traffi scheduled for transmission. A low watermark (LW) threshold and a high watermark (HW) threshold can be dynamically set for buffer 722. In various embodiments, low watermark (LW) threshold and high watermark (HW) threshold may be associated with corresponding byte level memory locations (e.g., a physical or virtual memory addresses) determined for buffer 722, which can be used to indicate an amount of uplink traffic contained in the buffer. In various embodiments, low watermark (LW) threshold and high watermark (HW) threshold may each be dynamically adjusted based on the uplink bandwidth set for cellular I/O interface through one or more bandwidth adjustments. During operation, for example, when high watermark threshold is reached for buffer 722 (e.g., because of packets being enqueued in the MAC layer without being scheduled in the uplink), MAC control logic 720 interrupts the host router using a decongestion interrupt to indicate there is congestion. In turn, host router logic 118 stops enqueueing packets in the cellular interface until the low water mark is reached (e.g., packets in the buffer are being transmitted and the buffer has been emptied to the low watermark threshold). Upon reaching low watermark threshold, MAC control logic 720 interrupts the host router again using the decongestion interrupt and the flow of uplink traffic sent to cellular I/O interface can be resumed. In various embodiments, the decongestion interrupt can be a control word, bit, byte, etc. indicating that the high watermark threshold or the low watermark threshold has been reached.