MPEG Multimedia Middleware (M3W) Integrity Management
MPEG doc#: N8693
Date: October 2006
Authors: Johan Muskens & Jean Gelissen (Philips)
1. Introduction
MPEG, a working group in ISO/IEC, has produced many important international standards (for example: MPEG-1, MPEG-2, MPEG-4, MPEG-7, and MPEG-21). MPEG feels that it is now important to standardize an Application Programming Interface (API) for Multimedia Middleware (M3W) that is based on a defined set of requirements [1]. This API provides a uniform view to a multimedia middleware platform that can be realized by a number of different vendors.
The M3W specification supports software systems that can be upgraded and extended during their lifetime (possibly at runtime). Upgrading and extension means changing the software configuration of a device. This introduces the opportunity to add features to a device or improve existing features in the period that a device is owned and used by a consumer. This allows reducing time to market (not all features need to be implemented at the moment a product is released) and new business models. At the same time (runtime) upgrading and extension introduces the challenges of maintaining / restoring a consistent software configuration that is suitable for a specific device.
In order to give device vendors the opportunity to control the consistency of the software on their product ISO/IEC 23004 Part 7 [2] – Integrity Management specifies an optional framework for integrity management. The goal is to have controlled upgrading and extension. Basically this means reducing the chance of breaking the system during an upgrade / extension and giving the ability to restore a consistent configuration when things have gone wrong.
2. Integrity Management Framework
The approach of the Integrity Management framework towards a consistent software configuration is based on a model describing the software and hardware configuration of a device and consists of the following activities:
- Monitoring: This basically comes down to extraction of the model that describes the configuration of the terminal (self model).
- Diagnosis: Based on the self model framework will need to determine whether there is a fault in the configuration.
- Repair: The faults that have been identified during diagnosis will need to be removed when this is possible.
Monitoring, Diagnosis and Repairing are closely related. The example scenario in the following figure illustrates this relation. System Integrity Management mechanisms can also remove known faults that have not been activated, this means that (in contradiction to the example) there is no need to "wait" until a failure occurs.
The previous example introduced the three main roles of the integrity management framework. Each of these roles has its own responsibility in the overall goal of maintaining / restoring a consistent software configuration
- Terminal role: The main responsibilities of the Terminal role are to expose a model of the current software configuration and also to offer basic software configuration facilities (add / remove / upgrade components or applications).
- Terminal Manager role: The main responsibilities of the Terminal Manager role are to monitor (model retrieving), diagnosis (finding faults in the software configuration) and repair (generate and execute a repair script that consists of basic configuration actions).
- Database role: The main responsibility of the Database role is to provide knowledge which is used for diagnosis (rules) and also for repair (solutions).
The individual roles of the Integrity Management framework can be deployed in different ways in order to support different integrity management scenarios. The only constraint is that the Terminal role must be deployed on the managed device. The Integrity Management framework is able to support remote management scenarios as well as local management scenarios.
3. Summary
The Application Programming Interface (API) for Multimedia Middleware specified by M3W provides a uniform view to the Multimedia Middleware in a device. A realization of such a middleware can be provided by a number of different vendors. The M3W specification contains a specification of an integrity management framework. The goal is to maintain / restore a consistent software configuration in a dynamic software environment. It can give the device vendor some control of software upgrades and extensions that would otherwise be completely out of control and a threat for the consistency of the software, thus the proper functioning of a device.
4. References
[1] The Multimedia Middleware (M3W) requirements are in the annex to the Multimedia Middleware (M3W) Requirements Document Version 2.0 (ISO/IEC JTC1/SC29/WG11 N6981). A Call for Proposals derived from these requirements was issued at the 70th MPEG Meeting in Palma, Mallorca
[2] ISO/IEC 23004, Information Technology — Multimedia Middleware, The M3W standard.