Layar Platform Overview

The architecture of Layar platform basically has 5 components:

• The Layar Reality Browser: Client on the mobile device of the user
• The Layar Server: The heart of the Layar service, which provides the interfaces to the Layar Reality Browser, the Layar Publishing site and the external Layar Service Providers.
• The Layar publishing Website: A website on which developers can register new layers, manage their layers and accounts.
• The Layar Service Providers that will be created by 3rd party developers. Layers based on Funda, Hyves, Flickr are examples.
• The layer Content Sources that provide the content to be viewed in the Layar Reality Browser, like Flickr.com for example. Layer Content Sources are not necessarily separated from the Layar Service Providers, but will in general be different logical entities, as existing geo-coded databases and web services don't support the Layar Developer API.

The interfaces that are exposed to third parties are:

• The Layar Client API: This is the interface between the Layar Server and the Layar App. This interface is not open to the public.
• The Layar Developer API: This is the interface between the Layar Server and the Layar Service Providers. Developers can create their own layers and submit them via the Layar Publishing Website to be added to the Layar service. The API is used to fetch live data about the layer.

How does it work ?

A general flow of using the layar platform is:

1. A User launches Layar Reality Browser on a supported mobile device.
2. Layar Client will send a request to the Layar Server.
3. Based on the request, the Layar Server will retrieve layer definitions from the publishing website. 
4. A list of retrieved layers will be sent by the Layar Server and displayed on the Layar Client. 
5. The User launches a layer from this list
6. A getPOIs request is sent to the Layar Server.
7. The Layar Server forwards the Layer Service Provider of that layer.
8. The layer Service Provider returns AR content based on the Developer API (getPOIs response) back to the Layar Server.
9. The Layar Server validates the getPOIs response and sends it back to the Layar Client.
10. The Layar Client displays the getPOIs response nicely to the User.