Presence-Enabled Services Improves communication efficiency by providing end users with the ability to control access to their availability and location Enhanced value remains the driving force behind Voice over Internet Protocol services This white paper addresses: • Applicable standards work • New presence-enabled services • Lucent’s plans to support presence-enabled services Contents Abstract .............................................................................................3 Introduction ......................................................................................3 Presence Framework .........................................................................4 Implementation of Presence-Enabled Services ...........................................9 Conclusion .......................................................................................11 Appendix..........................................................................................12 Instant Messaging and Location Services Overview..................................12 Glossary ...........................................................................................13 2 Abstract The need for enhanced value remains the driving force behind Voice over Internet Protocol (VoIP) services. Communications services should be accessible from many places – home, office and on-the-go, independent of the type of communication device deployed. Enhanced value means simplified, efficient communications and improved productivity. Lucent satisfies this need for value by accelerating convergence. Lucent’s Accelerate™ VoIP solutions include revenue generating next-generation applications with presence-enabled features that subscribers are demanding today. Lucent Technologies has developed the key network infrastructure elements for providing presence-enabled services. In addition, the open programmable services architecture supports the integration of third party partners to further develop presence-enabled services. This white paper discusses the applicable standards work, describes several new presence-enabled services and highlights Lucent’s plans to support these new services. Introduction Presence technology allows end users and network elements to know the status and availability of other end users in order to improve communications efficiency. The concept of presence was initially associated with instant messaging service. It allowed an end user to recognize the presence of a friend or colleague online to send or receive messages. Today, presence has expanded to include monitoring the registration and the busy or idle status of any type of end user device, including wireless phones, VoIP clients, traditional POTS phones, push-to-talk clients, multimedia clients, and more. In addition, the concept of presence has been extended to include availability, which allows an end user to explicitly share their availability to communicate with their colleagues. Typical availability states include out of office, in a meeting with a client, in a conference call, on vacation, away sick, etc. An end user can provide this information, or it can be inferred from the end user’s online calendar. Another dimension to presence is location, which refers to the geographical location of an end user’s device. Wireless networks can triangulate signal strength measurements to provide the location of wireless handsets and PDAs. More recently, the concept of location was extended to laptop based, instant messaging clients or IP softphones that might connect to wireline access networks at work, home or remote locations. By collecting and disseminating presence information (status of end user devices, availability of the individual and location), family members, friends and colleagues can select the most effective and appropriate means of communicating. Personal calls no longer need to interrupt important business situations. Emergency communications can be directed to the device that happens to be active and idle. Network applications (for example, find me/follow me service) can use presence information to efficiently and appropriately route or block incoming communication requests. For example, a call to an office wireline phone can be forwarded to a wireless phone if the wireless phone is active and idle and the end user’s availability indicates that he or she is not in a meeting. 3 Presence Framework The Internet Engineering Task Force (IETF) has proposed a general 1 M. Day, J. Rosenberg, and H. Sugano, “ framework for sharing presence information1 along with a set of event A model for presence and instant packages that can be used to specify the status of user clients.4, 5, 6, 7 In messaging,” RFC 2778, Internet addition, the IETF proposed the use of Session Initiation Protocol (SIP) for Engineering Task Force, Feb. 2000. communicating presence information.2, 3 2 A. B. Roach, “ Session Initiation The 3rd Generation Partnership Project (3GPP) has defined a reference Protocol (SIP) – specific event architecture for supporting presence services.8, 9 In addition, the notification,” RFC 3265, Internet Parlay/OSA Forum has defined a set of APIs that can be used to create Engineering Task Force, June 2002. presence and location-enabled services. A simplified view of the presence 3 J. Rosenberg, “A Presence Event services architecture is shown in Figure 1. Package for the Session Initiation Protocol (SIP)” internet draft, Internet Presence Suppliers Watchers Engineering Task Force, January 2003. Work in progress. 4 Presence User J. Rosenberg and H. Schulzrinne “An Agent INVITE Inititiated Dialog Event Presence Presence-Enabled Package for the Session Initiation Server Applications Protocol (SIP)” , draft-ietf-sipping- Presence Network dialog-package-02, Internet Agent Engineering Task Force, June 2003. Presence Clients TAS Policy 5 MSC GMLC J. Rosenberg “A Session Initiation VLR IMS MPC Protocol (SIP) Event Package for Registrations” draft-ietf-sipping-reg- event-00.txt, Internet Engineering Task Figure 1 – Presence Services Architecture Force, April 2003. 6 Vijay K. Gurbani, Igor Faynberg, Hui- Presence user agents provide explicit user status information to the Lan Lu, Alec Brusilovsky, Musa presence server. Explicit user status information might include an Unmehopa, Kumar Vemuri, and Jorge indication that the user is not available to receive any communications. Gato, “The SPIRITS (Services in PSTN The presence network agent utilizes network status information to Requesting Internet Services) Protocol” provide implicit status information about the end user to the presence draft-ietf-spirits-protocol-06.txt server. See Table 1 for examples. In addition to receiving network Internet Engineering Task Force, updates, the presence server can poll the presence network agent to August 2003. receive network presence information on demand. 7 Vijay K. Gurbani, Sudha Gouthama, Byron J. Williams “Early Implementation of the Services in PSTN Requesting Internet Services (SPIRITS) Protocol” draft-gurbani- spirits-implementation-00.txt, Internet-Draft August 2003. 8 3GPP TS 22.141: “Presence Services, Stage 1”. 9 3GPP TS 23.141; “ Presence Service; Architecture and Functional Description. 4 Status Information Presence Presence and Availability Network Agent Instant Messaging server Client is registered with Instant Messaging server Client is currently engaged in an Instant Messaging session Home Location Register (HLR) Wireless device is registered with a wireless service provider Visiting Location Register/Mobile Wireless phone is busy or idle Switching Center (VLR/MSC) Push to Talk server Push to Talk client is registered with the Push to Talk server Push to Talk client is idle or engaged in a Push to Talk session IP Multimedia Subsystem (IMS)* IP Phone client is registered with IP multimedia service provider IP phone client is idle or engaged in a IP multimedia session Circuit switch TDM Phone is busy or idle Conference bridge Identification of end users connected to a conference bridge Identification of speaker Telephony Application Server (TAS) A call is waiting for an end user A call is waiting for a pick up group Mobility Location (MPC and GMLC) Wireless phone is busy or idle Location of wireless device Table 1 – Examples of Network Presence Agents and Presence Information Watchers are typically application servers that use presence information to provide end user services. Presence services can be divided into two general categories: • Information to end users • Information to network services. By collecting presence information across multiple devices and displaying that information to other end users, end users can determine the best method to contact each other. Network services are those services that use presence information to automatically reroute or redirect incoming communication sessions. For example, a presence-based find me/follow me application server could instruct a Telephony Application Server (TAS) serving landline phones to forward an incoming call to a wireless handset if the wireless handset is registered and idle. Generally, location has been associated with a wireless handset. However remote workers and road warriors have laptop-based VoIP soft-clients and instant messaging clients that are also portable. These clients may connect to the network via dial up, DSL, cable modem, ethernet or WiFi access networks. If the location of these clients were known, some of the location-based services for wireless handsets could be extended to these portable clients. Furthermore,