Presence as a source of users' status information has been maturing over the past few years. It has grown increasingly granular -- moving from the terse "Away" to more informative descriptions like "On the Phone" or "Off-site with client; back at 2." Groupware, Web conferencing and telephony applications have also begun incorporating presence information, broadening its impact.
Now, figures in the Internet communications community are working to take presence to the next level by creating a framework for merging users' location data into their presence information. That's long been viewed as a logical add-on to the basic availability data now available in most implementations of presence.
But there are important considerations to take into account before simply merging the data. Access to users' geographic information needs to be subject to user control, much like presence is handled in most consumer instant messaging clients -- which generally enable users to hide their availability status from certain classes of fellow users, such as unknown contacts. Otherwise, everyone on a network could have unrestricted knowledge of others' whereabouts without any form of authorization.
GEOPRIV is close to finalizing on a recommendation -- a Request for Comments, in IETF parlance -- for just such a system. That draft recommendation, authored by Neustar's Jon Peterson and known officially as "A Presence-based GEOPRIV Location Object Format," is actually based on earlier work done in formulating the basic requirements for presence data -- the Presence Information Data Format (PIDF).
"Historically, in the IETF, there was this big IM and presence war -- I guess it isn't officially over, yet," said Peterson, who also serves on the Internet Engineering Steering Group, the IETF's standards leadership body. "One of the fallouts of that was the IMPP Working Group ... One of the things it produced was a common core set of tools to be used by IM protocols in the ITEF to ensure interoperability ... that was PIDF. And this other effort was started on geographic data."
Eventually, however, individuals involved with both IM and with geographic data realized that much of the same privacy and authorization controls had to be applied to each.
"More and more, we realized that the GEOPRIV problem was really the presence problem -- the mechanisms of subscriptions, tracking, receiving periodic updates over time, and authentication, who you lie to and who you tell the truth to ... All these arguments look the same," Peterson said. "Consequently, we just revised the presence work ... The draft is an extension to the PIDF document that essentially adds a new element that permits one to carry geographical information with presence."
Initially, a few early drafts and informational documents were created by the group. But little work progressed until this month saw the first concerted effort to gain RFC status for GEOPRIV recommendations -- which would effectively preserve Peterson's draft as a standard.
The latest effort doesn't aim to hammer out a standard for geographic information itself. Rather, it's based on current geographic data standards, and focuses instead on encapsulating location information within presence data, and applying the same sorts of user preferences. Geography Markup Language (GML) is the expected location format over which the GEOPRIV draft's specifications will be applied.
"There is related work out there, tons of it in the GEOPRIV working group for providing more specific policy tools and language ... and OpenGIS (Geographic Information Systems) and the GML 3.0 spec seem adequate for expressing simple and extremely complex coordinate space," Peterson said. "Tons of people work on OpenGIS. We're not experts on that. We're experts on things like security and privacy ... At its core, [the new draft] is pretty format-agnostic."
According to the language of the draft and earlier reference documents on which it was built, the specification document creates only the minimum markup necessary for a user to detail preferences concerning that external privacy rules be followed, any limitation on length of data retention, and any limitation on any retransmission or further disclosure.
Peterson said the group aims to bring the document to Last Call -- one of the final approval steps before RFC status -- in late February or early March.
Assuming the document is approved, goes to RFC, and is widely adopted as a de facto specification -- which is fairly likely, considering the wide array of industry support within the GEOPRIV Working Group and its other affiliated groups in the IETF -- the stage could be set for a number of compelling applications.
In addition to, say, relatively mundane uses like being able to pinpoint a roving colleague in advance of a big meeting, enterprise systems could support rules-based messaging using geographic data. In an event of a server failure, for instance, a system could swing into action, alerting only IT administrators who were nearby and available.
Peterson, an early figure in Session Initiation Protocol (SIP) and SIP for Instant Messaging and Presence Leveraging Extensions (SIMPLE) has his own anticipated scenarios. For one thing, VOIP applications based on SIP could see a major boost with the introduction of location-based data, which would provide necessary infrastructure for 911 emergency calling.
"The ability to convey within a SIP 'Invite' message for VOIP the location of a caller is critical, and it's been a really substantial gap in SIP's story for some time," he said. He also cited gaming applications as a personal favorite.
"But what we're trying to do is provide the foundational building blocks that people can apply as they want," he added. "The challenge is to balance the need to share this information with users' personal privacy -- hence this whole concept of GEOPRIV."
Christopher Saunders is managing editor of InstantMessagingPlanet.com.