Concepts
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Concepts

Description of the OMA-DM protocol

The OMA-DM Protocol is based on the HTTP protocol. XML messages are exchanged between the client and the OMA-DM server through HTTP requests. The complete specification of the OMA-DM protocol is available here: www.openmobilealliance.org/Technical/current_releases.aspx

Data representation

The device's data are represented by a tree nodes. This tree is stored twice. Once on the client device and once on the OMA-DM server. The synchronization of these two trees is made during the exchanges between the client device and the server.

There are two types of nodes in the tree: nodes and leaf. Each node and leaf contains four informations

• Name: the name of the node
• Data: the data of the node
• Type: the type of the node (MIME type for leaf node and empty or Management Object Identifier for interior node)
• Format: the standard OMA-DM format of the node

For the leaf, all informations have to be fill.

For the nodes, Type an Data information must be empty. Name is the name of the node. The value of Format is "node".

The OMA-DM tree must contain some specific nodes and leafs. Some other nodes are just optional. The complete description of the basic tree is available in the OMA-DM specifications. After the non optionals nodes, the tree can contain other nodes and leafs which are specific for the client device.

OMA-DM commands

The protocol provides some commands which could be sent by the server and executed on the client device. Below is the list of commands which are supported by the simulator:

• Add: insert a new node in the tree
• Delete: delete a node in the tree
• Get: ask the data of one node
• Replace: change the data of one node
• Copy: copy the value of one node to another
• Exec: invoke an executable file on the client device. It's usually used for FUMO (Firmware Update Managed Object).

The result of the execution of one command is send by the client device to the OMA-DM server. Once, the server receive the result, it can choose to send a new command to the client device.

Getting started		Tasks