MTP

The Media Transfer Protocol is based upon, and is compatible with, the Picture Transfer Protocol (PTP) which is commonly used by digital imaging devices and printers for the exchange of pictures. PTP supports only the transfer of pictures. MTP allows the transer of most types of media and is aimed at intelligent multifunction storage devices, such as digital cameras, portable media players and mobile phones.

Some key aspects of MTP:

• It is intended for transient connectivity between devices which normally function unconnected.

• It is optimised for very large data stores.

• A device may act as either a data producer or a data consumer. This refers to the direction in which data is transferred. For example image files may be uploaded from a Symbian device acting as a producer and music files downloaded to the same Symbian device acting as a consumer.

• A device may act as either an Initiator or a Responder. Typically the Initiator is the 'more responsible' of the two devices.

• Besides enabling data transfer MTP enables some command and control of the connected device (the responder)

• Data is transferred as an atomic binary object so the data types that can be transferred are not restricted.

For a more complete description of MTP, and to download the MTP Porting Kit, please visit the Microsoft website

The Symbian implementation of MTP

The Symbian implementation of MTP is compatible with Microsoft's MTP Enhanced specification v0.95. Symbian devices conform to the Windows Portable Device (WPD) architecture.

Compatible versions of Microsoft Windows are:

• Windows XP with Windows Media Player version 11 or higher

• Windows Vista

A Symbian device can take only the Responder role.

The Symbian implementation of MTP is delivered with an implementation of the USB Still Image Class (SIC). Provision has been made in the design for additional transports, such as TCP/IP, to be added and for the transport interface to be made available to partners in future releases.

The Symbian implementation of MTP is delivered with a File System Data Provider. The File System Data Provider gives access to the public file system. Data caged and system files are not available. The data provider allows files and folders to be viewed, moved, copied, renamed and deleted. Files can be copied between the PC and the device and vice versa.

It's likely that further data provider plugins, developed by partners, will cater for specific media types, such as music files, image files, contact data files and calendar data files. 'Cater' might mean display, play or edit the data through an appropriate application on the PC.