path: root/doc/features.txt

oFono - Open Source Telephony
*****************************

Purpose
=======

The purpose of this document is to enumerate all major functionality areas
of oFono.  In effect, this document will serve as the primary, up to date
source of oFono feature information.  It is intended for developers, managers
and users alike to quickly gauge the progress of the project and feature
availability.

Sim Toolkit
===========

Supported Proactive Commands:

- Display Text proactive command support.  Upon receiving the proactive
  command notification oFono decodes it, including performing character
  conversion from packed/unpacked GSM 7bit and UCS2 to UTF-8 encoded text.
  The registered agent is then called using the DisplayText method on the
  SimToolkitAgent interface to handle the user interaction aspects.

  SIM-specified duration are handled.  If immediate response to the SIM
  is required, oFono sends a terminal response immediately.  DisplayText
  method is still executed normally, until a timeout occurs or a new
  proactive command arrives from the SIM.

- Get Inkey proactive command support.  When this command is received,
  oFono decodes it and checks what "flavor" it is.  Depending on this, the
  SimToolkitAgent is called with a different method call:
	* If the Get Inkey flavor indicates that this is a simple Yes/No
	  confirmation, then the RequestConfirmation method is called.
	* If the Get Inkey flavor indicates that the SIM only expects digits,
	  then the RequestDigit method is called.
	* Otherwise the RequestKey method is called

  SIM specified durations are handled, if the user agent does not respond
  in the time allowed, then the 'No Response' Terminal Response is generated
  automatically.

- Get Input proactive command support.  When this command is received,
  oFono decodes it and checks what "flavor" it is.  Depending on this, the
  SimToolkitAgent is called with a different method call:
	* If the Get Input flavor indicates that the SIM only expects digits,
	  then the RequestDigits method is called.
	* Otherwise the RequestInput method is called

- More Time proactive command support.  This command is intended to notify
  that the SIM is still busy processing a command.  For oFono, this proactive
  command is a no-op.  It is always replied to successfully.

- Setup Menu proactive command support. When this command is received, oFono
  parses the new main menu structure and updates its MainMenu and MainMenuTitle
  properties which reflect the items, icons and the alpha text of the
  proactive command.  Soft key support and menu help system are ignored by
  oFono.

- Select Item proactive command support.  When this command is received, oFono
  decodes it and dispatches it to the SimToolkitAgent by calling the
  RequestSelection method.  This method is passed the menu selection title,
  the selectable items and the default, if any.

- Timer Management proactive command support.  oFono supports starting,
  stopping and querying timer state flavors of this command.  Up to eight
  timers are supported.  This proactive command is handled completely
  inside oFono and no external user interaction is required.

- Set Up Idle Mode Text proactive command support.  Whenever oFono receives
  this proactive command, it updates the IdleText property on the main
  SimToolkit interface.  Indications that this property has changed are
  handled by the usual means.

- Send DTMF proactive command.  Whenever oFono receives the Send DTMF command,
  it checks that there are calls in progress and DTMF is possible.  If so,
  DTMF characters are passed to the voicecall atom to be transmitted to the
  modem.  The appropriate terminal response is sent to the SIM once the DTMF
  tones have been played or the call has been disconnected.

  NOTE: This command can also be handled by the modem.

- Play Tone proactive command.  Whenever oFono receives a Play Tone proactive
  command it checks whether the tone is to be continuous/looped or played once.
  It then calls the SimToolkitAgent PlayTone or LoopTone method as appropriate.
  The sound that will be played will be determined based on the sound type
  that is passed to the agent.  It is up to the system integrator to provide
  the appropriate sounds.

- Send USSD proactive command.  Whenever oFono receives a Send USSD proactive
  command it checks whether there are any USSD / SS operations in progress.
  If an operation is in progress, the appropriate terminal response is sent
  without performing the Send USSD operation.  Otherwise the USSD string
  is sent to the network, and the response is sent back to the SIM in the
  terminal response.

  NOTE: This command can also be handled by the modem.

- Language Notification proactive command. Whenever oFono receives a Language
  Notification proactive command, it prints the language code and sends
  terminal response to the SIM immediately.

- Provide Local Information proactive command.  Whenever oFono receives a
  Provide Local Information proactive command, it checks the type of the
  information requested.  If the information is about the time/date or the
  language of the terminal, it responds to the command with the appropriate
  terminal response. The time/date information is obtained using localtime().
  The language information is obtained by checking the LANG environment
  variable.  All other information requests are expected to be handled by
  the modem.

- Send Short Message proactive command.  Whenever oFono receives a Send SMS
  proactive command, it parses the PDU and submits it to the outgoing SMS
  queue.  A terminal response is sent to the SIM When the raw PDU has been
  sent, or failed to be sent.

  NOTE: This command can also be handled by the modem.

- Set Up Call proactive command.  When oFono receives a Set Up Call proactive
  command, it checks whether the UICC has indicated that the user should be
  informed.  In this case the SimToolkitAgent is called with the
  ConfirmCallSetup method.  If the user has authorized the operation, or if
  the user's confirmation was not indicated oFono will setup the call and
  optionally inform the user.  The information sent by the SIM will be
  available on the resulting voice call object.  The relevant properties are
  Information and Icon.

  NOTE: This command can also be handled by the modem.

- Refresh proactive command.  The specification defines 7 types
  of Refresh requests:
	- NAA Initialization
	- NAA File Change Notification
	- NAA Initialization and File Change Notification
	- NAA Initialization and Full File Change Notification
	- UICC Reset
	- NAA Application Reset (2G only)
	- NAA Session Reset (3G only)

  oFono can fully perform the the first four types of Refresh.  The
  remaining three must be handled by the modem or its driver with a
  notification sent to ofono.  Regardless of whether the command is
  handled by the modem or not, oFono will check whether there are any
  calls or ussd operations active.  If there are, the appropriate
  response will be sent (e.g. busy on call or screen busy terminal
  response.)  Otherwise a positive response will be sent to the driver.
  In the case of a 'UICC Reset' the driver / modem can interpret this
  that it is safe to reset the UICC.

  Alternatively, the driver / modem can notify the core of the SIM removal
  / SIM insertion events without using the Refresh proactive command.  It
  is up to the driver / modem to perform a warm reset.  In particular, 3GPP
  31.111 mandates that any change to EFimsi is done by using 'UICC Reset',
  'NAA Application Reset' or 'NAA Session Reset'.  Please see 3GPP 31.111
  Section 6.4.7.1.

  Other types are handled by oFono flushing the EF cache of the files
  affected (or the entire SIM cache in case of Full File Change Notifications)
  and re-reading the affected files.  Any properties derived from these
  Elementary Files will be updated and signaled using PropertyChanged.

  NOTE: This command can also be handled by the modem.

- Sim icon support.  oFono supports icons that are stored on the SIM.  If the
  SIM notifies oFono that an icon is available for a particular proactive
  command, oFono passes this information to the UI.  The UI is able to obtain
  the icons by using GetIcon method on the SimManager interface.  The icons
  are read from the SIM and converted into XPM format.

- Text attribute support.  Whenever oFono detects that text attributes have
  been given to any text or alpha string, it applies them and converts the
  resulting text to HTML.  The UI is expected to be able to display such
  HTML formatted text.

Envelopes:

- Timer Expiration envelope support.  Whenever a timer expires (as started by
  the Timer Management proactive command) oFono forwards, this envelope type
  to the SIM.  No external user interaction is required.

- Menu Selection envelope support.  The user can initiate a proactive command
  session by selecting something from the Sim Toolkit main menu.  This is done
  by using the SimToolkit's SelectItem method.  As a result, oFono will send
  the Menu Selection envelope to the SIM.

- CBS-PP Download envelope support.  When oFono receives a cell broadcast
  and on a channel listed in EFcbmid, it is dispatched to the SIM using the
  CBS-PP Download envelope.  No user interaction is required or signaled
  whenever this occurs.

- SMS-PP Download envelope support.  When oFono receives an sms message
  addressed to the SIM, it is dispatched to the SIM using the SMS-PP Download
  envelope.  No user interaction is required or signaled whenever this occurs.

  Please note that many current modems do not support returning RP-ACK and
  RP-ERROR acknowledgement PDUs back to the network.  This is required by the
  CAT specification for SMS-PP Download.  E.g. the sim response to the SMS-PP
  Download Envelope is to be stored in an RP-ACK / RP-ERROR PDU and returned to
  the network.  It is thus anticipated that modems will transparently handle
  this feature in the firmware.

The following commands are expected to be handled by the modem:

- Send SS proactive command.  oFono does not explicitly support this proactive
  command since AT modems do not provide the low level information necessary
  for oFono to generate a valid response.  The modem (or driver) shall handle
  this command.  Optionally the modem (or driver) can inform oFono that the
  proactive command has been received and is being handled by the modem, as
  well as when the terminal response has been sent by the modem.  oFono will
  display the necessary user information for this time period if this
  information is included in the proactive command.

 -----------------------------------------------------------------------
|	Feature			|	Support	|	Implemented by	|
|				|		|			|
 -----------------------------------------------------------------------
|Profile Download		|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|SMS-PP Data Download		|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|Cell Broadcast data Download	|	YES	|	BASEBAND or ME	|
|				|		|			|
 -----------------------------------------------------------------------
|CALL CONTROL BY SIM		|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|DISPLAY TEXT			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|GET INPUT			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|GET INKEY			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|MORE TIME			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|PLAY TONE			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|POLL INTERVAL			|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|POLLING OFF			|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|REFRESH			|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|SELECT ITEM			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|SEND SHORT MESSAGE		|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|SEND SS			|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|SEND USSD			|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|SET UP CALL			|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|SET UP MENU			|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(MCC, MNC, LAC, cellId &	|		|			|
|IMEI)				|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(NMR)				|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|SET UP EVENT LIST		|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: MT CALL			|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: CALL CONNECTED		|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: CALL DISCONNECTED	|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: LOCATION STATUS		|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: USER ACTIVITY		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: IDLE SCREEN AVAILABLE	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: CARD READER STATUS	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: LANGUAGE SELECTION	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: BROWSER TERMINATION	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: DATA AVAILABLE		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: CHANNEL STATUS		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: ACCESS TECHNOLOGY	|	YES	|	BASEBAND	|
|	CHANGE			|		|			|
 -----------------------------------------------------------------------
|EVENT: DISPLAY PARAMETERS	|	NO	|			|
|	CHANGED			|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: LOCAL CONNECTION	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: NETWORK SEARCH MODE	|	YES	|	BASEBAND	|
|	CHANGE			|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|POWER ON CARD			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|POWER OFF CARD			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|PERFORM CARD APDU		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|GET READER STATUS		|	NO	|			|
|(Card reader status)		|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|GET READER STATUS		|	NO	|			|
|(Card reader identifier)	|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|TIMER MANAGEMENT		|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	ME		|
|(Date, Time, & Time Zone)	|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|SET UP IDLE MODE TEXT		|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|RUN AT COMMAND			|	YES	|	BASEBAND	|
|				|		|			|
 -----------------------------------------------------------------------
|SEND DTMF			|	YES	|	BASEBAND-ME	|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	ME		|
|(Language)			|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(Timing Advance)		|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|Language Notification		|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|LAUNCH BROWSER			|	YES	|	ME		|
|				|	(MIN)	|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(ACCESS TECHNOLOGY)		|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|OPEN CHANNEL			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|CLOSE CHANNEL			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|RECEIVE DATA			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|SEND DATA			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|GET CHANNEL STATUS		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|SERVICE SEARCH			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|GET SERVICE INFORMATION	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|DECLARE SERVICE		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|Text Attributes		|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|ICONS				|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|Bearer Independent Protocol	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|VARIABLE TIMEOUT		|	YES	|	ME		|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(IMEISV)			|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(SEARCH MODE CHANGE)		|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|Extended Launch Browser	|	NO	|			|
|Capability			|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(battery state)		|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|RETRIEVE MULTIMEDIA MESSAGE	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|SUBMIT MULTIMEDIA MESSAGE	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|DISPLAY MULTIMEDIA MESSAGE	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|SET FRAMES			|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|GET FRAMES STATUS		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|PROVIDE LOCAL INFORMATION	|	YES	|	BASEBAND	|
|(NMR(UTRAN))			|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|USSD Data Download and		|	NO	|			|
|application mode		|		|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: BROWSING STATUS		|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------
|EVENT: MMS TRANSFER STATUS	|	NO	|			|
|				|		|			|
 -----------------------------------------------------------------------

Modem
=====

- 'silent' modem reset. Sometimes modems get in a bad state and have to reset
  itself. Now oFono can be notified when a reset happens and do proper work to
  put the modem back to work restoring the state before the reset.

- Lockdown support. Through the Lockdown property on the Modem D-Bus API, one
  can power down the modem and lock it disallowing any other application to
  use that modem. Useful for firmware update and similar stuff.

Short Messaging Service
=======================

- Unique identifier for incoming and outgoing SMS messages.  Whenever a
  message is received or sent by oFono, a unique ID is generated for that
  message.  The id is relevant to all segments of an SMS and in the case of
  incoming messages is only generated when the SMS is fully assembled.  The
  hash used is SHA1.  This unique identifier is used to identify the SMS
  message to history plugins as well.

- SMS Status Report support.  oFono allows requesting of SMS Status Reports
  via the MessageManager UseDeliveryReports property.  If enabled, oFono
  will set the SRR bit and process incoming status reports.  oFono takes
  care of collating the status reports for multi-fragment messages.  Once all
  status reports are received, the UI is notified either via DBus or history
  plugin API.

- Source / Destination port addressing scheme from 3GPP 23.040.  A special
  header is used to indicate the source / destination port of the application
  this SMS message belongs to.  oFono provides a handler registration
  framework where plugins can handle the reception of such messages.  The
  handler can be registered to receive messages which contain a specific
  source and destination port, or a wildcard.  When such messages are received,
  they are matched against the registered handlers and dispatched appropriately.

  oFono takes care of de-fragmentation of such SMS messages, so the handler
  is informed only once the entire message has been received, and the data
  payload has been extracted.

- Smart Messaging Service - vCard support.  oFono provides the ability to send
  and receive vCard objects through the SmartMessaging interface.  vCards can
  be sent using the SendBusinessCard method and received using the
  SmartMessagingAgent framework.

- Smart Messaging Service - vCalendar support.  oFono provides the ability to
  send and receive vCalendar objects through the SmartMessaging interface.
  vCalendars can be sent using the SendAppointment method and received using
  the SmartMessagingAgent framework.

- WAP PUSH notification support.  oFono allows the reception of WAP PUSH
  messages via SMS through the use of the PushNotification interface and the
  PushNotificationAgent framework.

- Persisting of outgoing SMS messages.  Whenever oFono is asked to send an SMS
  message, it adds it to an internal queue and persists it on disk.  The queue
  is persistent across reboots of oFono and allows to queue SMS messages even
  while the modem is offline.

GPRS
====

- GPRS suspension event support.  The packet data service may be temporarily
  suspended while a circuit switched service such as voice call or SMS is
  active.

- GPRS context protocol support.  oFono supports the followig types of GPRS
  contexts:
	- IPv4
	- IPv6
	- Dual Stack (IPv4 + IPv6)

Location Reporting
==================

- GPS support. Many modem manufacturers provide a GPS unit with their modem
  hardware.  Upon client request oFono can turn this unit on or off and pass a
  file descriptor in which client may receive the desired location reporting
  data.

SIM
===

- Fixed Dialing support.  oFono reads the necessary bits from the SIM to
  check if FDN support is allocated and enabled in the SIM.  If enabled,
  oFono halts the SIM initialization procedure and the modem remains in the
  PRESIM state.  In this state oFono will only allow emergency calls.

- Barred Dialing support.  oFono reads the necessary bits from the SIM to
  check if BDN support is allocated and enabled in the SIM.  If enabled,
  oFono halts the SIM initialization procedure and the modem remains in the
  PRESIM state.  In this state oFono will only allow emergency calls.

- Read / Write EFcfis / EFcphs-cff.  oFono reads EFcfis/EFcphs-cff SIM files
  to check if VoiceUnconditional call forwarding rule is enabled.  If enabled,
  ForwardingFlagOnSim will be set and VoiceUnconditional may contain the
  "forwarded to" number if the number is available.

- Support SIM retry counters. oFono exports all the retry counters available on
  SIM, e.g., PIN, PIN2, PUK and PUK2. Whenever an action changes them, a signal
  is sent with the updated values, so user can keep track of how many times
  he/she can still give a wrong pin before the SIM locking down.

Radio settings
==============

- Fast dormancy support. A fast dormancy feature can be enabled in the
  cellular modem to conserve power when the end user is not actively
  using the device but some networking applications are online using
  packet data.

- Frequency Band Selection support. This feature allows the user to limit the
  frequency bands in which the cellular modem can operate.

Text Telephony
==============

- TTY (hearing impaired) support, also known as Cellular Text Modem (CTM).
  In case it's supported by the modem, oFono allows the user to enabled
  or disable it through the TextTelephony interface.

Emergency Calls
===============

- Emergency number reporting.  During SIM initialization phase oFono reads
  EFecc in order to bootstrap the emergency calling codes provided by the SIM.
  Emergency number list is exposed via the EmergencyNumbers property on the
  VoicecallManager interface.  If SIM is present, list is the union of default
  emergency numbers(112, 911), numbers in EFecc and Network / Modem reported
  emergency numbers.  If SIM is not present or EFecc has not been read yet,
  list is the union of default emergency numbers(112, 911) and emergency
  numbers without SIM(119, 118, 999, 110, 08 and 000).

- Emergency call reporting.  When a voicecall is made to a number present
  on the EmergencyNumbers list it is automatically flagged as an emergency
  call.  This is done by setting the Emergency property on the Voicecall
  interface to TRUE.

- Emergency Mode.  oFono supports a concept of an 'Emergency Mode'.  This mode
  is activated when any emergency procedure is ongoing and restricts certain
  actions (e.g. setting the modem offline).  Emergency procedures are e.g.
  ongoing emergency calls, or network initiated location requests related to
  the emergency call.  The state of the emergency mode is exposed via the
  Emergency property on the org.ofono.Modem interface.  This property is
  intended to be used by power management daemons and other entities which
  need to be aware of the ongoing emergency operation.

Supplementary Services
======================

- CNAP support.  The Calling Name Presentation supplementary service is
  supported by oFono.  One can query whether the service is provisioned in the
  network by using the CallSettings interface.  If the network reports the
  calling name, it is presented on the Voicecall interface using the Name
  property.  If no calling name is given, the Name is empty.

- CDIP support.  The Called Line Presentation is supported by oFono. One can
  query whether the service is provisioned in the network by using the
  CallSettings interface.  If the network supports this service, the number
  dialed by the remote party is presented through the Voicecall interface using
  the IncomingLine property.

Voice Calls
===========

- Long phone number support. oFono supports dialing of phone numbers up to
  80 digits long.

- Supplementary service notifications related to mobile originated (MO) and
  mobile terminated (MT) calls.  oFono supports certain supplementary service
  notifications, typically reported by CSSU and CSSI, that are related to
  MT/MO calls:
	- outgoing call has been forwarded (+CSSI: 2)
	- outgoing calls are barred (+CSSI: 5)
	- outgoing call barred due to call barring on remote party (+CSSI: 6)
	- incoming call is a forwarded call (+CSSU: 0)
	- call has been put on hold by the remote party (+CSSU: 2)
	- call has been retrieved by the remote party (+CSSU: 3)
	- call has been added to a mpty call by the remote party (+CSSU: 4)

Flight Mode
===========

- Flight Mode support.  oFono uses the 'Online' property on the Modem interface
  that controls the state of the radio.  When Online state is False, all
  interfaces that depend on the radio being on are removed.  Other interfaces
  enter reduced functionality mode where only certain actions are available
  that do not depend on the radio.  E.g. setting various settings on the local
  store or the SIM.

Network Registration
====================

- Support for PLMN_MODE bit from CPHS Customer Service Profile (CSP) within
  the 'Value Added Services' service group.  oFono reads this file when the
  network registration atom has been initialized.  If EFcsp indicates that
  manual network registration is not allowed, oFono enters into 'auto-only'
  registration mode.  Updates to this file via STK Refresh is also supported.

PPP Stack
=========

- Support for Protocol Field Compression (PFC) packets.  The oFono PPP stack
  supports both receiving and sending of packets with PFC enabled.  The user
  can also control whether PFC capability is advertised to the peer, and used
  during transmission.

- Support for Address & Control Field Compression (ACFC) packets.  The oFono
  PPP stack supports both receiving and sending of packets with ACFC enabled.
  The user can also control whether ACFC capability is advertised to the peer,
  and used during transmission.

Modem Emulator
==============

- Support HandsFree Profile Audio Gateway (HFP AG) emulator.
  Supported feature are: 3-way calling, ability to reject a call, enhanced call
  status, enhanced call control and report of extended error results code.