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Schedules for Things and Markets

Yesterday, I sat in on the final day of the Calendaring and Scheduling Consortium's semiannual conference ( CalConnect is a consortium that promotes interoperability between dissimilar calendaring and scheduling systems. I was there to scout out their just unveiled xml serialization of ICalendar. I think we will use it a lot in buildings and on the smart grid.

I have written before that we need a simple way to exchange information about events. This is a quite different task than time synchronization. Events have duration and may evolve multiple participants. In the old Mission Impossible shows I watched while growing up, they would plan a series of events, often events that require close cooperation between several actors, whether they were good guys or bad guys. Then they would synchronize their watches and the drama would begin. CalConnect does not worry about synchronizing the watches, but about all the planning for activities that need to happen together.

In the enterprise-responsive building, rooms and access control should respond to normal business events in the building. Schedule a meeting for 9 people in Conference Room 2 on the third floor? Catering a wedding for 200 in ballrooms A and B? The building system should prepare that room to be comfortable by then, and plan for adequate ventilation to keep that many people alert. Enterprise responsive buildings can move beyond efficiency to doing the right thing at the right time.

On the smart grid, we will be constantly comparing events. Next Tuesday at 10:00 power will be expensive. The factory is able to sell excess cogeneration back to the grid during the lunch break, 12:15 to 1:00 five days a week. The office building can shut down early in response to the grid because almost everyone is at the sales meeting. The primary benefits of the smart grid are from aligning supply and demand, and thereby being able to rely on intermittent energy while avoiding expensive or "dirty” energy".

As people, we share schedules and meetings every day using ICalendar. Surprisingly, there has been no accepted standard for writing ICalendar in XML.

On Thursday, Steve Lees (Microsoft), Cyrus Daboo (Apple), and Mike Douglas (RPI) posted a draft of an XML serialization of ICalendar to the IETF (Links below). It will be assigned an RFC "real soon now"™. Steve also created a web based converter into which you can paste your own ICalendar object and get a translation.

I have some quibbles with the draft:

I would like to see the location (latitude and longitude) component of the specification use standards from the Open Geospatial Consortium. For now, they should use KML; you used KML the last time you pinned something to Google Earth. (Imagine all the concert listings in your town automatically pinning themselves to a map). I would like them to consider allowing other OGC defined objects—such as a polygon, tracing out the area affected by the event. I would even like to make this field multi-valued, allowing multiple points to be affected by the event.

The standards also includes the Uniform Resource Indicator (URI) as does the ICalendar object. You may be familiar with the more specific form of the URI, the Uniform Resource Locator (URL)—you typed the URL into the browser to get to this page. The word URI is the more general case and includes more options, including all URLs. I would like to be able to add a list or URIs to an event.

I would like to see the description be typed and multi-valued as well. When you are using a calendar, the description is the part of the message that may show up as the conference call #, the agenda, etc. In the standard this shows up as:

            Looking forward to a good discussion, 1-800-888-1234

I would like this the be multi-valued, and able to support more object types than text.

Of course, each of these multi-value issues (location, reference, description) would break backward compatibility. As they are not defined in iCalendar, they could not be converted back into iCalendar. These are not complaints; as I said above, that’s why people put drafts up in public.

I am very glad to see this one up in public...and I hope to incorporate their work into oBIX soon.

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Reader Comments (1)

Have you seen the work that Jon Udell has been doing for the elm city project?

It's not exactly the same issue you're talking about here, but a few conversations between you two may save you some time when you start building this stuff out.


June 6, 2009 | Unregistered CommenterTerrell

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