Intermediary Node Latency Estimation via Cumulative Density Functions

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless communication systems face challenges in maximizing transmission capacity for inelastic services like VoIP over time-varying channels, as they require low latency and dedicated bandwidth, leading to inefficiencies in resource utilization due to the need for predefined maximum latency across multiple nodes.

Innovation Solution

An intermediary node with a time estimator calculates the relative arrival times and creates a cumulative density function to establish a threshold for packet loss, allowing for increased latency and optimized transmission scheduling based on channel conditions, thereby reducing required transmission resources without compromising round trip time requirements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If a predefined maximum latency is enforced at each node to guarantee low round trip time for VoIP services, then the round trip time requirement is met, but the total transmission capacity of the system is reduced

Engineering Contradiction:
Improveround trip timeVSAvoidtotal transmission capacity
Core Design Contradiction:
Loss of timeVSProductivity

Solution Approach 1:

The patent changes the parameter of latency allocation from fixed equal distribution to variable distribution based on cumulative density functions. By calculating CDFs of packet arrival times at each node and determining threshold values that satisfy the overall latency requirement, the system dynamically adjusts allowable latency at each node rather than enforcing a rigid predefined maximum, thereby increasing total transmission capacity while meeting QoS requirements

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic latency allocation where each node adapts its maximum allowable latency based on observed packet arrival patterns and CDF calculations. The scheduler at each node dynamically determines the maximum latency for the next packet based on the CDF threshold, allowing the system to flexibly utilize available time slots and increase overall transmission capacity compared to static latency enforcement

Inventive Principle:
Principle #15Dynamics

2Loss of time

If transmission capacity is dedicated to VoIP services to ensure low latency, then the round trip time requirement is satisfied, but the flexibility for scheduling concurrent traffic flows is diminished

Engineering Contradiction:
ImprovelatencyVSAvoidscheduling flexibility
Core Design Contradiction:
Loss of timeVSAdaptability or versatility

Solution Approach 1:

The patent changes the scheduling approach from dedicated capacity allocation to adaptive capacity allocation based on CDF-calculated latency thresholds. The scheduler determines the maximum latency for each packet dynamically based on the CDF of arrival times and the overall latency budget, allowing flexible scheduling of VoIP packets alongside other traffic flows while guaranteeing the required latency performance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces CDF-based threshold values as an intermediary mechanism between the latency requirement and the scheduling decision. Rather than directly dedicating capacity or enforcing fixed latency, the CDF threshold acts as a mediator that translates the overall latency budget into node-specific maximum latency values, enabling flexible scheduling while maintaining QoS guarantees

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentUS8488485B2Packet latency estimation
Publication Date: 2013.07.16 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)
  • US8488485B2 patent drawing
  • US8488485B2 patent drawing
  • US8488485B2 patent drawing

AI summary

An intermediary node is adapted for receiving a sequence of packets from a server, wherein the intermediary node comprises a time estimator adapted for performing the following steps—resolving the sequence number (k) and time of arrival to the intermediary node for at least a plurality (q) of incoming packets; establishing the frame period of the incoming packets (T); establishing a sequence of normalized packet arrival times (ek) as corresponding to the established frame period (T); calculating the relative arrival time (rtrec, k) of the plurality (q) of incoming packets in relation to the normalized packet arrival times; creating a cumulative density function (CDF) for a given sequence of packets; and establishing the threshold value for the relative arrival time (rtPL) yielding the predefined packet loss (PL) based on the cumulative density function (CDF).