Understanding Presence in Telecommunications
Presence is really not an application by itself but is rather an enabler of applications, adding value to them. We shall define presence information within a telecommunications context including the state of an object or device, status of attachment or engagement, device type, usage or activity, and coarse location information. All of these attributes can be used to distinguish the presence of an entity or object. In telecommunications or computing an object or device can be many things including a PC or laptop, circuit-switched or IP-based phone, mobile/cellular phone, or other wireless data, voice or signaling device.
Evolution of Presence
Presence started as an inherent part of instant messaging (IM). Standards bodies and industry forums included:
- Open Mobile Alliance (OMA)
- Internet Engineering Task Force (IETF)
- Generation Partnership Project (3GPP)
Standardization efforts included:
- IETF’s SIP (Session Initiation Protocol) and SIMPLE (SIP for Instant Messaging and Presence Leveraging Extensions)
- APEX (Application Exchange), Prim (Presence and Instant Messaging Protocol)
- The open XML-based XMPP (Extensible Messaging and Presence Protocol), more commonly known as Jabber
- OMA’s (Open Mobile Alliance) IMPS (Instant Messaging and Presence Service) created specifically for mobile devices.
Presence has since evolved to become a stand-alone capability, not tied only to IM. Furthermore, presence has evolved to support specific network architecture for IMS, but first let’s review some basic presence concepts and definitions.
Example Application: Presence and IPTV
IPTV and Presence Mash-up: Buddies can discover what each other are currently watching, given the options specified in the Presence service (see also Presence section). Users “presence” information on the network can be augmented to show the television or video program the user is currently watching based on what the IPTV Content Server is currently delivering to the end user’s premise equipment. In the case of a multi-user household, it is not clear how the system is supposed to know which user is watching the program being delivered. But, let’s assume those details will be worked out. The high level view of providing this service is something like this:
Messaging IPTV Mash-up: Once buddies have discovered that they are currently watching the same program, or they have intentionally chosen the same program, they can then instant message while simultaneously viewing the program. This can make the experience of watching television a shared experience between friends that are not in the same room.
Incoming call notification: The IPTV user can be alerted to an incoming call on their IPTV screen, including the calling name. In this way, the user need not get off the sofa during a program to look for the cordless phone (which isn’t where it’s supposed to be), only to determine it isn’t someone they want to talk to anyway, then return to the sofa annoyed at the unwelcomed interruption.
For more information, see: