SupplementaryServices hierarchy
==========================

Service		org.ofono
Interface	org.ofono.SupplementaryServices
Object path	[variable prefix]/{modem0,modem1,...}

Methods		string, variant Initiate(string command)

			Sends a USSD command string to the network
			initiating a session.  When the request is handled
			by the appropriate node of the network, the
			method returns the response or an appropriate
			error.  The network may be awaiting further response
			from the ME after returning from this method and no
			new command can be initiated until this one is
			cancelled or ended.

		string Respond(string reply)

			Send a response to the network either when
			it is awaiting further input after Initiate()
			was called or after a network-initiated request.

		void Cancel()

			Cancel an ongoing USSD session, mobile- or
			network-initiated.

		dict GetProperties()

			Returns Supplementary Services related properties. See
			the properties section for available properties.

Signals		NotificationReceived(string message)

			Signal is emitted on a network-initiated USSD
			request for which no response is needed.

		RequestReceived(string message)

			Signal is emitted on a network-initiated USSD
			request for which a response must be sent using
			the Respond method unless it is cancelled or
			the request is not supported.

		PropertyChanged(string property, variant value)

			Signal is emitted whenever a property has changed.
			The new value is passed as the signal argument.

Properties	string State [readonly]

			Reflects the state of current USSD session.  The
			values have the following meanings:

			"idle"			No active USSD session.
			"active"		A session is active between the
						network and the ME, the ME is
						waiting for a reply from the
						network.
			"user-response"		The network is waiting for the
						user's response, client must
						call Respond().