Insight: What does Android offer?
November 20, 2007

Android is a software stack for mobiles, newly presented by Google and others in the the Open Handset Alliance. The speculations on its future successes are in full roll. But what could the system offer for companies? Android contains an operating system, middleware and programs. The Open Handset Alliance (OHA) has released a software development kit and based on that, it is possible to draw conclusions on the competency of the system. Does it have superhuman capabilities, as the name implies? Mobil Magazine has taken a closer look at the system and its contents.

Android consists of four layers. At the bottom, there is a Linux core, version 2.6. It contains, among other things, drivers for displays, camera, Bluetooth, wireless network and more hardware.

On top of that, there are a number of libraries. For instance the OpenGL/ES, 2D graphics with SGL, FreeType for font handling and a simple database engine called SQLite, as well as security via SSL. There is a media library based on PocketVideo's OpenCore, which should make it possible to record and play mpeg4, h.264, mp3, aac, amr and to show jpg and png images. As part of it, there is the Android runtime, using a virtual machine called Dalvik. Each program runs in a separate process, in its own virtual machine. That should render programs relatively stable.

The layer above that is an application framework of programs, handling among other things windows and telephony. There are content provisioning features which is intended to make it possible to share data with other applications, for instance to get access to the phone contacts or calendar items from your own programs. Resource handling (internationalization, localization, graphics, layout) and views (such as buttons and lists) are included here. There are also notifications as well as an embeddable web reader, based on WebKit. That means Android mobiles will have the same web engine as the Iphone and as Mac's web browser Safari. All applications in the framework should be able to share functions with other programs.

In the top layer wee find the things that a user will see every day, the application layer. Android will, according to its own statements, come with its own e-mail client, SMS text messaging, calendar, maps, web reader and contacts. All applications are written in Java by using standard tools such as Eclipse. That means that there is already a great number of programmers with the right knowledge and some existing programs that might be easy to port to the new platform. To attract developers, however, Google has announced a competition with a 5 million dollar prize divided among the top twenty programs for the platform.

On the other hand, Java programs are usually a bit more resource intensive than programs written directly on top on low level interfaces close to the hardware. By using a Java framework, on the other hand, the platform might be easy to adapt to different kinds of hardware, such as existing mobiles.

For developing, there is an emulator, so it is possible to develop programs without having an Android mobile. There is no news on which underlying hardware capabilities such as processor speed and display sizes it will emulate, though.

Nothing of the above is in any way new, both using or not using Java, but is readily accessible in the Microsoft Windows Mobile platform as well as in Symbian, as in other mobile systems projects based on Linux.

As a license for open source, the OHA has chosen to use the General Public Licence (GPL) as well as the Apache license. GPL can be said to be a very open license, but the Apache version allows companies to develop code and then not share it with others. Google, however, says that it has protected Android from this by forcing members of the OHA to sign an extra agreement where companies promise to not change the code in ways that make it incompatible with the code of other members. The question then remains how that is going to be controlled.

By: Jonas Kämpe