Tuesday, December 13, 2005

The OSGi Mobile Specification

Last week the OSGi Alliance made the latest draft available of the Mobile Platform Specification. This draft is function complete and it is not likely to change anymore; only the last bits are being ironed out.

The Mobile Platform Specification is developed in conjunction with the JCP in the JSR 232. It would soon be available from their web site as well (it takes a surprising long time to reach the www.jcp.org web site after the document is submitted). The OSGi Mobile Platform Specification is up for inclusion in the upcoming JSR 249 Mobile Architecture for CDC. If the Mobile OSGi Platform is included in JSR 249, it will mean that higher-end mobile phones will start running OSGi service platforms.

The OSGi Mobile Platform primarily adds the Service Platform to mobile devices. This is exactly the OSGi R4 Service Platform that is already used for home automation, vehicles, desktop, and high end servers. However, the mobile experts, under guidance of Motorola and Nokia, have extended the platform with a number of services that were deemed crucial for the mobile market. The key focus has been on device management, managed deployment, application management.

A key requirement for the OSGi Mobile Platform was to simplify application programmer. MIDP has been a great source of revenue for operators because there are so many Midlets available. Obviously, any Mobile Platform must support this revenue stream. However, there are multiple MIDP versions and derivatives in this world. Worse, there also exist other application models like DoJa, BREW, Symbian, and other application models. OSGi Service Platforms are capable of hosting a large range of application models within their architecture. The Mobile platform has added two service specifications. The Foreign Application Specification defines how applications can interact with the OSGi service registry. Foreign Applications can both use as well as provide services. The Application Management Specification defines how different application models can be managed by other applications: launching, stopping, enumerating, etc. This specification allows screen managers that work on different mobile phones.

The Device Admin Specification borrows its concepts from the OMA DM standard, which is basically a tree based model for configuration information. The API allows both the implementation of nodes in this tree as well as the manipulation of the tree. For integrity, the manipulation can be fully transactional. A similar API was developed in Siemens’ JSR 246, we are working with this JSR to align the APIs. JSR 246 was originally based on the OSGi source base but over time deviated. It would be ridiculous to have two APIs that look very much alike but would not be compatible; the two teams therefore work actively together to resolve the issues.

The Mobile Expert Group felt that bundles were too small in granularity. We therefore added a new artifact: Deployment Packages. A Deployment Package, with mime type application/vnd.osgi.dp, can contain bundles and other resources. An advanced mechanism allows resources in a Deployment Package to be handled by an extendable mechanism. This architecture allows the processing of certificates, configuration information, and other types of resources. A special Deployment Package can be used to update an installed Deployment Package; such Fix-Packs only contain the new resources and bundles. The Deployment Admin service provides facilities, to enumerate, query, install, and uninstall Deployment Packages.

The OSGi Mobile Platform holds great promise for mobile devices. It provides a secure and managed computing platform that does not cripple its applications. Watch this space for information about SDKs for the Mobile Service Platform.

Do you have any questions about the Mobile Service Platform Draft, ask me!

     Peter Kriens


  1. I want to know a listed information about OSGi mobile .Can any one tell me how can I ?


  2. can anybody tell me where can I get more info about OSGi mobile.