Abstract: iLoc is an ultrasound ranging based indoor localization system deployed at the iHomeLab at Lucerne University of Applied Sciences and the Embedded Systems Lab at Stuttgart University of Applied Sciences. The system tracks humans in AAL scenarios which bear an ultrasound transmitter for example in the form of a name badge. The transmitter can be localized with an average accuracy well below 1 meter, by means of wired reference nodes distributed in the lab rooms. A small battery may suffice for several month of transmitter operation. The original deployment consists of wired nodes. Data and power is supplied via the IPoK fieldbus. Configuration data, i.e. node positions, are measured manually and entered in a database. The system participated at the first EvAAL competition 2011 and reached best accuracy score. iLoc+, A modified system comprising battery powered wireless nodes and an automatic configuration procedure was used at the second EvAAL Competition 2012. Both solutions are compared with focus on obtained accuracy and installation effort, using data from the respective competitions. Results of the comparison are discussed and possible optimizations are outlined. The implications may also be relevant for other positioning technologies in the AAL sector.
