@INPROCEEDINGS{hightower2002locstack,
  author    = "Jeffrey Hightower and Barry Brumitt and Gaetano Borriello",
  title     = "The Location Stack: A Layered Model for Location in Ubiquitous Computing",
  booktitle = "Proceedings of the 4th IEEE Workshop on Mobile Computing Systems \& Applications (WMCSA 2002)",
  publisher = "IEEE Computer Society Press",
  address   = "Callicoon, NY",
  pages     = "22-28",
  month     = "June",
  year      = {2002}
}