Fundamental Ubicomp Issue #1 - World Models
One cross-cutting aspect common to many ubicomp applications is the need for a world model, some computational representation of the physical world. Some issues here include:
Using sensors and existing data sources to acquire and update the model
The precision and accuracy of that model with ground truth (ie the real world)
Coming up with standard representations that can be shared across multiple apps
Controlling how the world model is shared with others
Mediating the conflict between high-fidelity models with privacy
The last two points are especially interesting ones, and point to a larger question with respect to ubicomp. It seems that the more reliable and more fine-grained ubicomp world models are, the less inherent plausible deniability there is. Imagine if you could no longer tell white lies on the cell phone about where you were or what you were doing. In a perfect system, there is no place to hide.
Of course I'm pushing an extreme case, but here...