Key Factors for Position Errors in 802.11-based Positioning Systems

Indoor positioning systems based on 802.11 and fingerprints offer reasonably low position errors. We study the key factors for position errors by systematically investigating (1) the number of access points, (2) the number of samples in the training phase, (3) the number of samples in the position determination phase, and (4) the setup of the grid of reference points. Further, we squeeze out the best of the positioning system by selecting advantageous values for these parameters. For our study, we utilize a test environment with a size of about 312 square meters that is covered with 612 reference points arranged in an equally spaced grid