The Symbian OS (779886), страница 51
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Theprotocol modules perform the actual encoding and decoding of messages,support SIM card message store management functions and interact withthe Telephony Server (via ETel Multimode) for transmission and receptionof message.SMS messaging clients include the messaging application supportcomponents at the application-services level, for example the SMS MTM,CDMA MTM and Java messaging components.Similarly, the WAP Stack is a client for WAP messaging, typically toexpose a Wireless Datagram Protocol (WDP) service to a WAP client. TheWAP protocol module in turn directly cooperates with the SMS protocolmodule, which undertakes the transaction with the Telephony Server.Note that the Telephony Server may not be the ultimate providerof the message service, for example if an SMS is requested to be sentover a Bluetooth link.
In this case, the Telephony Server creates a furtherSocket Server session requesting the appropriate bearer and the messaginginterface is a serial port plug-in for the appropriate bearer rather than theTSY interface to onboard phone hardware.Part of the messaging support consists of utility classes that implementencoding and decoding functions and streaming, logging and backupserver interface classes. Utilities are provided as standalone DLLS (linkedto by clients at compile time).Interfacing to the BasebandTSY modules are the telephony equivalent of the Serial Server’s CSYvirtual serial-port implementation modules and are defined and loadedby the ETel Framework. A TSY is an ECom (plug-in framework) compliantplug-in that provides the glue between Symbian OS Telephony Servicesand the phone baseband (the telephony stack).The Telephony Server passes client requests made to it on sub-sessionobjects (which may be based on the Core API, Symbian-supplied extension APIs, or custom APIs created by licensees by extending the coreframework) to the TSY, which translates them into proprietary requeststhe baseband understands.
The TSY plug-in model is a direct borrowingof the CSY model used by the Serial Server.TELEPHONY SERVICES225The Telephony Server framework provides the abstract base classes foreach of the objects implemented by a TSY, representing phones, lines,calls, faxes and extensions.Symbian OS supplies four TSYs as reference implementations. TheMultimode TSY shipped for the first time in Symbian OS v7, as anupgraded and renamed version of the original GSM.TSY that shippedwith ER5, incorporating GPRS support. The CDMA and SIM TSYs alsoshipped for the first time in Symbian OS v7, as did a first version ofa Telephony Reference Platform (TRP) TSY. The Symbian OS v9 TRPTSY runs on Texas Instruments H2 development board hardware but isdesigned to be easily ported to other platforms.Component CollectionsTelephony Utilities CollectionThis collection contains helper components that use the telephony serverbut which are not used by it.
See Figure 9.15.Table 9.6 Telephony Utilities ComponentsComponent NameDevelopment NameTelephony WatchersTELEPHONY WATCHERSPhonebook SyncPHBKSYNCDialDIAL• The Telephony Watchers are watcher Framework plug-ins that monitor telephony conditions and report them as Publish and Subscribeproperties, including current signal strength, battery level and whethera call is in progress. They were introduced in Symbian OS v8.• The Phonebook Sync server enables synchronization of contactsbetween a phonebook application and entries stored in the IntegratedCircuit Card (ICC) or ‘SIM’ card of a device. It was originally introducedas part of the ETel Multimode extension 3G support for UMTS andCDMA2000.Telephony UtilitiesDialPhonebookSync.TelephonyWtchrs.Figure 9.15 Telephony Utilities components226THE COMMS SERVICES BLOCK• The Dial component consists of dialing utilities the use of which isdeprecated from Symbian OS v9.Telephony Server CollectionThe ETel telephony server and core framework implements the basictelephony functions and is extended by the Multimode framework intoa uniform generic API for all mobile telephony independent of theunderlying network, with additional packet-data extensions for 2.5G and3G packet services, CDMA-specific extensions, plus SIM Toolkit utilities,fax support and a third-party API that opens a common subset of telephonyfunctions to third-party application developers.
See Figure 9.16.Table 9.7 Telephony Server ComponentsComponent NameDevelopment NameETel Server and CoreETELETel 3rd Party APIETEL3RDPARTYFax Client and ServerFAXETel MultimodeETELMMETel Packet DataETELPCKTETel SIM ToolkitETELSATETel CDMAETELCDMA• The ETel Server and Core API provides clients with access to telephonyfunctions on Symbian OS. It implements the standard Symbian OSclient–server framework, providing a client-side API (as a separateDLL to which clients link). The server in turn translates these intoTSY requests, which are passed on to a TSY module. The serverdynamically loads and unloads TSY modules at client request. The TSYimplements a customized interface to the onboard hardware (althoughin a two-box case, it would route back through an appropriate socket toTelephony ServerETelServer/CoreETel3rdPartyAPIETelMultimodeETelPacketDataETelCDMAETelSIMToolkitFigure 9.16 Telephony Server componentsFaxClient/ServerTELEPHONY SERVICES227use the requested communications port).
Like other communicationsservers, ETel is a CPM that runs as a thread within the communicationsprocess.• The ETel Multimode component extends the Core ETel API to provide,as far as possible, a uniform API, for making voice, fax, data ormultimedia calls, that is independent of the underlying mobile networkand phone architecture (e.g. 2G, 2.5G, or 3G).• The ETel 3rd Party API is implemented as a sub-session providinga subset only of the Core ETel, ETel Multimode and ETel PacketAPIs. Unlike the other main telephony APIs, which are restricted tolicensees, the ETel 3rd Party API is open to third-party developers,enabling them to make applications that can use the telephony featuresor create dedicated, phone-aware applications.• The ETel CDMA component extends the ETel multimode sub-sessionto implement a high-level API for CDMA-specific telephony applications.• The ETel Packet Data component is an ETel Telephony Serverextension framework enabling access to GPRS Release 97/98,CDMA/CDMA2000, Release 99 (GPRS and UMTS) and Release 4(UMTS) packet services.
It enables clients to configure, modify andactivate a PDP context for a network packet-switched service and tocontrol a packet-switched connection.• The ETel SIM Toolkit provides the functionality of a GSM/WCDMA(U)SIM Application Toolkit, implemented as a sub-session.• The Fax Client and Server is not an ETel extension. The server is a DLLthat provides a framework for adding fax functionality to applicationsand is driven by the Fax Client via ETel and a suitable TSY. The FaxClient is accessed by applications through the Messaging Send-AsAPI.SMS Protocol Plug-ins CollectionThese protocol modules and other plug-ins implement telephony-basedmessaging for GSM and CDMA SMS and WAP messaging.
See Figure 9.17.SMS Protocol PluginsSMSPRTFigure 9.17CDMASMSPluginsWAPPRTCDMAWAPPRTSMS Protocol Plug-ins components228THE COMMS SERVICES BLOCKTable 9.8 SMS Protocol Plug-ins ComponentsComponent NameDevelopment NameSMS PRTSMSSTACKWAP PRTNo unitCDMA SMS Plug-insCDMASMSSTACKCDMA WAP PRTNo unit• The GSM SMS PRT protocol module enables its clients to send andreceive GSM SMS messages, enumerate and delete messages fromphone stores and read and write SMS parameters on the SIM. It isimplemented as an ESock plug-in protocol module, therefore clientsinteract with it though an instance of RSocket; all operations areinitiated by IOCTL calls on RSocket.• The CDMA SMS protocol implementation conforms to IS-637 and supports Wireless Paging, Wireless Messaging, Voice Mail Notification,Broadcast SMS, Service Category Programming, Wireless EnhancedMessaging and Card Application Toolkit Protocol.• The WAP PRT protocol module is used by the WAP Stack for sendingand receiving SMS messages.• The CDMA WAP PRT provides functional equivalents of the GSMWAP protocol module.SMS Utilities CollectionThe GSM Utilities and SMS Utilities components are used by the SMSprotocol modules (the SMS stack) to assist in creating and processing SMSmessages.
For example, GSM Utilities includes encoding and decodingroutines and SMS Utilities includes streaming classes (to stream messageobjects across the Socket Server), logging classes and interfaces to thebackup server. They are implemented as utility DLLs that are linked to byclients. See Figure 9.18.SMS UtilitiesGSMUtilitiesSMSUtilitiesFigure 9.18 SMS Protocol UtilitiesTELEPHONY SERVICES229Table 9.9 SMS Protocol UtilitiesComponent NameDevelopment NameGSM UtilitiesGSMUSMS UtilitiesSMSUTelephony Server Plug-ins CollectionThis collection contains reference telephony server plug-in modules (TSYfiles), loaded by the Telephony Server. See Figure 9.19.Telephony ServerPluginsMultimodeTSYCDMATSYSIMTSYFigure 9.19 Telephony Server Plug-insTable 9.10 Telephony Server Plug-insComponent NameDevelopment NameMultiMode TSYMMTSYCDMA TSYCDMATSYSIM TSYSIMTSY• The MultiMode TSY provides the GSM and GPRS functionality.
It usesthe AT command interface to communicate with the phone or modemvia standard AT commands over a serial or infrared link.• The CDMA TSY is the CDMA equivalent of the MultiMode TSY forGSM. The ETel TSY reference plug-in for CDMA is replaced on anactual device by a hardware-specific licensee TSY.• The SIM TSY is a simulator module designed to enable automatedtesting of a range of operating-system components in a simulatedGSM, CDMA and WCDMA mode. It does not communicate withany real hardware (neither a modem nor a phone) but instead usesstatic configuration data and dynamic system-agent notifications tosimulate the presence of phone hardware.
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