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) - GPRS provisioning support. oFono will automatically configure GPRS contexts if no prior configuration (e.g. user or provisioning) has been detected. If the GPRS atom detects that provisioning is required it will query the inserted sim card for the Service Provider Name and call each registered provisioning plugin with the MCC, MNC, SPN of the inserted SIM card. If the provisioning information is provided, then it is used to populate the initial context configuration. - GPRS provisioning via 'Mobile Broadband Provider Info'. oFono supports provisioning of GPRS contexts via Mobile Broadband Provider Info project's database. 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. - Support for 3GPP Service Provider Name (EFspn), CPHS Operator Name String (ONS) and CPHS Short Operator Name String fields. oFono always tries to read the EFspn field first. If this is not available, then oFono tries to read the CPHS variant. If neither are available and the appropriate bits are set in the CPHS Information field, oFono tries to read the CPHS Short ONS field. oFono then reports the network name via the 'Name' property. 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 for Bluetooth HandsFree Profile Audio Gateway (HFP AG). oFono supports the underlying AT command protocol specified by BT HFP version 1.6. Supported features include 3-way calling, ability to reject a call, enhanced call status, enhanced call control, report of extended error results code and indicator activation. Audio management is assumed to be performed in another system component, e.g. PulseAudio. - Support for Bluetooth DUN profile. oFono supports the Dial Up Networking profile and all mandatory commands specified by BT DUN 1.1. For a list of supported commands please see doc/dialup-command-set.txt. CDMA Connection Manager ======================= - Support Network Initiated disconnection of Packet Data Service over CDMA (1xRTT and 1xEV-DO) systems. CDMA Network Acquisition ======================== - Support reporting of the received signal strength indicator (RSSI) measurement for the currently acquired CDMA network. - Support reporting of the received signal strength indicator (RSSI) measurement for the currently acquired 1xEV-DO data network. Bluetooth Sim Access Profile ============================ - oFono supports certain modems that can utilize remote sim cards (e.g. via SAP). This is done transparently to the user and all of oFono's APIs are supported on such devices (assuming the device itself supports the required features). Today the Telit UC864-G is supported in this mode. Bluetooth Handsfree Profile =========================== - Voicecall support. oFono supports the use of Bluetooth Handsfree capable devices to make voicecalls. All features are supported, including 3-way calls, multiparty calls, call waiting, etc. - Support for Handsfree specific protocol features. oFono clients can gain access to Bluetooth HFP specific features via the oFono Handsfree interface. These features include voice recognition activation, last number redial, etc.