WWAN Miniport Adapter (Windows Embedded CE 6.0)
The WWAN miniport adapter is used to manage establishment, configuration, packet transmission, packet reception and disconnection of NDIS-based data connections. The WWAN miniport adapter does not expose any interfaces to OEMs. The miniport interface is handled internally by the VEM (Virtual Ethernet Miniport).
The following illustration shows the data flow from the protocol interface level to the radio hardware.
At boot time, an instance of a WWAN miniport is created. This instance is used solely for managing configuration and connection of the WWAN miniport.
An OID is sent from the protocol driver (TCP/IP or NDISUIO) with information about the networks (APNs) available for connection. The WWAN miniport adapter issues the command RIL_NDIS_SetGPRSContextActivated to establish a connection with a particular APN. Details such as the user name and password are passed to the command using the RILNDISGPRSCONTEXT structure. Once the connection has been established, the RIL sends a message to the WWAN miniport adapter notifying the adapter of success.
When a connection has been established, the VEM creates a new instance of the WWAN miniport adapter. This new instance is used for packet transmission and reception. This WWAN instance is similar in function to an ethernet connection. The instance persists until the connection with the APN has been disassociated. At that point, the WWAN miniport instance is destroyed.
Multiple WWAN miniport instances for packet transmission and reception can be active at the same time. One instance is established per APN connection. The WWAN miniport instance list is managed by NDIS.