1“Transforming Live, Inventing Future” A Seminar Report On GOOGLE VOICE By Swaruparani Sahu
2INDEX____________1. Introduction 42. Features in Google Voice 63. Networking protocols involved 84. Benefits of Google Voice 145. Conclusion 156. References 16
3Introduction and HistoryGoogle Voice is a telecommunications service by Google launched onMarch 11, 2009. The service provides a US phone number, chosen bythe user from available numbers in selected area codes, free of chargeto each user account. Inbound calls to this number are forwarded toother phone numbers of the subscriber. Outbound calls may be placedto domestic and international destinations by dialing the Google Voicenumber or from a web-based application. Inbound and outbound callsto US (including Alaska and Hawaii) and Canada are free of charge.International calls are billed according to a schedule posted on theGoogle Voice website.The service is configured and maintained by the user in a web-basedapplication, styled after Googles e-mail service, Gmail. Users must havean established US telephone service to activate Google Voice. Usersmust configure this and optionally, additional phone numbers that ringsimultaneously when the Google Voice number receives a call. The usermay answer and receive the call on any of the ringing phones. GoogleVoice provides additional features such as voicemail, call history,conference calling, call screening, blocking of unwanted calls, and voicetranscription to text of voicemail messages. Received calls may bemoved between configured telephones during a call.Google Voice is available only for users in the United States. Users mayselect a single US phone number from various area codes. Incoming
4calls to the number may ring simultaneously any of the usersconfigured phones or the accounts Google Talk feature. Based on thecalling number, or contact group (e.g., Family, Friends, Work), or ontime of day, e.g., disabling a home phone during business hours androuting calls to mobile or business number, individual numbers may beconfigured to ring. The service also features voicemail with indexableautomated voicemail transcription, accessible via a web browser, e-mail, or by phone. Google Voice provides automatic blocking of knownnumbers, e.g., telemarketers, the ability to switch lines in mid-call,differentiated voice mail greetings based on caller, SMS forwarding,and call recording. Additionally, customers of Gizmo5, a SessionInitiation Protocol (SIP) service vendor, may forward calls to theirGizmo service which may be answered using a free computerapplication or a web application.GrandCentral, founded in 2005 by Craig Walker and Vincent Paquetwith funding by Minor Ventures, was acquired by Google on July 2,2007, for US$95 million in a transaction led by Wesley Chan. On March11, 2009, the management of the service revealed that the team hadbeen working on it throughout that period, apparently in secret, andthat it was being rebranded "Google Voice”.] It was to keep most of thefunctionality originally offered in GrandCentral and add new featuresThe following figure shows the interface of Google voice.
5Features in Google Voice1. A single Google forwarding number to all of the users phonesUsing Google Voice we are able to establish a abstraction layer byproviding a single “Google number” to the world, which underneath isconnected to several telephone numbers at a time. Using such afeature enables the caller to ring all the phones of the person he/she iscalling to ensure that the call is picked at any cost. This feature alsoenables a user to customize which phone to ring depending on the timeof the day or the caller calling the number.
62. Call screeningAnnouncement of callers based on their number or by an automatedidentification request for blocked numbers3. Blocking calls from specified numbersIn an enhancement to the existing services provided by the telephonycompanies, Google voice allows handset independent blocking of callsfrom specific users. Those callers will hear a “number not in service”message when they call to the Google number of the said user.
74. Send, receive, and store SMS onlineConnecting the internet and the mobile phone has always been anobjective of Google. Using Google Voice we can send and receiveSMSes absolutely free of carrier charge. It also provides a facility tostore the SMSes in form of email in your gmail account.5. Voicemail transcriptsVoicemail is a feature using which we can hear audio messages ofcallers when we cannot pick up their calls. Google takes this feature astep further using which we can get a transcript of the voicemaildelivered to our inbox and sms which we can read rather than listening.Networking protocols involvedAs with any internet telephony service, Google voice is primarily basedon the Voice over Internet Protocol (VoIP) and coupled with the SessionInitiation Protocol (SIP) in the application layer.
81. Voice over Internet ProtocolVoice over Internet Protocol (Voice over IP, VoIP) is a general term for afamily of methodologies, communication protocols, and transmissiontechnologies for delivery of voice communications and multimediasessions over Internet Protocol (IP) networks, such as the Internet.Other terms frequently encountered and often used synonymouslywith VoIP are IP telephony, Internet telephony, voice over broadband(VoBB), broadband telephony, and broadband phone.Internet telephony refers to communications services — voice, fax,SMS, and/or voice-messaging applications — that are transported viathe Internet, rather than the public switched telephone network(PSTN). The steps involved in originating an VoIP telephone call aresignaling and media channel setup, digitization of the analog voicesignal, optionally compression, packetization, and transmission asInternet Protocol (IP) packets over a packet-switched network. On thereceiving side similar steps reproduce the original voice stream.VoIP systems employ session control protocols to control the set-upand tear-down of calls as well as audio codecs which encode speechallowing transmission over an IP network as digital audio via an audiostream. Codec use is varied between different implementations of VoIP(and often a range of codecs are used); some implementations rely onnarrowband and compressed speech, while others support high fidelitystereo codecs.VoIP can be a benefit for reducing communication and infrastructurecosts. Examples include: 1. Routing phone calls over existing data networks to avoid the need for separate voice and data networks.
92. Conference calling, IVR, call forwarding, automatic redial, and caller ID features that traditional telecommunication companies (telcos) normally charge extra for are available free of charge from open source VoIP implementations.3. VoIP can facilitate tasks and provide services that may be more difficult to implement using the PSTN. Examples include:4. The ability to transmit more than one telephone call over a single broadband connection.5. Secure calls using standardized protocols (such as Secure Real- time Transport Protocol). Most of the difficulties of creating a secure telephone connection over traditional phone lines, such as digitizing and digital transmission, are already in place with VoIP. It is only necessary to encrypt and authenticate the existing data stream.6. Location independence. Only a sufficiently fast and stable Internet connection is needed to get a connection from anywhere to a VoIP provider.7. Integration with other services available over the Internet, including video conversation, message or data file exchange during the conversation, audio conferencing, managing address books, and passing information about whether other people are available to interested parties
11The Session Initiation Protocol (SIP) is an IETF-defined signalingprotocol, widely used for controlling multimedia communicationsessions such as voice and video calls over Internet Protocol (IP). Theprotocol can be used for creating, modifying and terminating two-party(unicast) or multiparty (multicast) sessions consisting of one or severalmedia streams. The modification can involve changing addresses orports, inviting more participants, and adding or deleting media streams.Other feasible application examples include video conferencing,streaming multimedia distribution, instant messaging, presenceinformation, file transfer and online games.SIP was originally designed by Henning Schulzrinne and Mark Handleystarting in 1996. The latest version of the specification is RFC 3261 fromthe IETF Network Working Group. In November 2000, SIP was acceptedas a 3GPP signaling protocol and permanent element of the IPMultimedia Subsystem (IMS) architecture for IP-based streamingmultimedia services in cellular systems.The SIP protocol is an Application Layer protocol designed to beindependent of the underlying transport layer; it can run onTransmission Control Protocol (TCP), User Datagram Protocol (UDP), orStream Control Transmission Protocol (SCTP). It is a text-basedprotocol, incorporating many elements of the Hypertext TransferProtocol (HTTP) and the Simple Mail Transfer Protocol (SMTP).SIP employs design elements similar to the HTTP request/responsetransaction model. Each transaction consists of a client request thatinvokes a particular method or function on the server and at least oneresponse. SIP reuses most of the header fields, encoding rules andstatus codes of HTTP, providing a readable text-based format.A motivating goal for SIP was to provide a signaling and call setupprotocol for IP-based communications that can support a superset of
12the call processing functions and features present in the publicswitched telephone network (PSTN). SIP by itself does not define thesefeatures; rather, its focus is call-setup and signaling. However, it wasdesigned to enable the construction of functionalities of networkelements designated proxy servers and user agents. These are featuresthat permit familiar telephone-like operations: dialing a number,causing a phone to ring, hearing ringback tones or a busy signal.Implementation and terminology are different in the SIP world but tothe end-user, the behavior is similar.SIP-enabled telephony networks can also implement many of the moreadvanced call processing features present in Signaling System 7 (SS7),though the two protocols themselves are very different. SS7 is acentralized protocol, characterized by complex central networkarchitecture and dumb endpoints (traditional telephone handsets). SIPis a peer-to-peer protocol, thus it requires only a simple (and thusscalable) core network with intelligence distributed to the networkedge, embedded in endpoints (terminating devices built in eitherhardware or software). SIP features are implemented in thecommunicating endpoints (i.e. at the edge of the network) contrary totraditional SS7 features, which are implemented in the networkThe diagram next page clearly describes the working of the SIPprotocol.
14Benefits of Google Voice1. Lowering costs Free calls and SMS International calls as low as $0.02 per minute2. Managerial Benefits Voicemail transcripts. Reading of voicemail messages online Downloading of voicemails. Call recording and online archiving. Blocking calls from specified numbers3. Personal Benefits Answering incoming calls on any configured phone Switching of phones during a call Conference calling Notification of voicemail messages via email or SMS
15ConclusionGoogle has always tried to change the way we look at computing.And by creating the Google Voice application, the Mountain Viewgiant has shown its intentions again.Google Voice is the future of telephony as VoIP takes overtraditional and orthodox telephony protocols.The amount of services Google has been able to wrap with a freeprice tag itself is an example of cheaper technology enabling itsaccess to all sections of the human society to improve its livingstandard.Although Google Voice is currently available only in the US, it hasplans of expanding its usage in the Asia Pacific within the next 8-10months.Its advent is surely revolutionary and with stiff competitors likeSkype and Verizon in the market, the end user is surely going tobenefit from all the rush.