From the Queue to the Quality of Service

Policy: a Middleware Implementation

Institute of Industrial Control SystemsPolytechnic University of Valencia

José L. PozaJuan L. Posadas

José E. Simó

DCAI '09. 10th-12th June, 2009.University of Salamanca (Spain)

The “Queue-based Quality of Service Cycle” concept

Quality of ServiceRepresents the set of those quantitative and qualitative

characteristics of a distributed multimedia system necessary to

achieve the required functionality of an application [Vogel et al., 1995]

Set of service requirements to be met by the network while transporting a

flow [Crawley et al., 1998]

The collective effect of service performance, which

determines the degree of satisfaction of a user of the

service [ITU-T, 1994]

Quantitative and qualitative characteristics

Required functionality

Service requirements

Collective effect

Performance

Satisfaction

Characteristics

Quantitative characteristics

Messagequeues

Qualitative characteristics

Components and services

Required functionality

Queue-based system

Queue-based componentsQuantitative

characteristics

Parameterized system

Qualitative characteristics

Based on quantitative parameters

Standardized parameters

Architecture

DDS (OMG)

Parameterized objects

Queue-based objects

All objects inherit

the QoS characteristics

System

A message queue for each component

Quality of Service cycle1. The Queue provides the simple parameters.

2. From queue parameters, component can obtain the QoS parameters

3. QoS parameters are analyzed and combined. The result determines the compliance of the user-defined requirements.

4. If the result is out of limits, the policy acts on the concretes message queues

Collective effect

Each single component contributes with a small part of the final component QoS values.

Components don’t requires a global QoS formula.

Implementation

System

Robot simulator

Implementation

Atomic components Quantitative parameters

AgentsQualitative parameters

ConclusionsQoS is based on the

DDS model

Qualitative parameters based on

message queue

Quantitative parameters Based on

the composition of the quantitative

parameters

Requirements feedback the

message queue

Predict temporal aspects to agents

Know the message flow to each component of a control algorithm

Defining the values of the QoS parameters, a system can self-configure the behaviour of the message queues

System don’t requires a global QoS formulation

From the Queue to the Quality of Service

Policy: a Middleware Implementation

Institute of Industrial Control SystemsPolytechnic University of Valencia

José L. PozaJuan L. Posadas

José E. Simó

DCAI '09. 10th-12th June, 2009.University of Salamanca (Spain)

The “Queue-based Quality of Service Cycle” concept

Thanks for your attention

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