Performance analysis of dynamic priority shifting

We investigate the benefit of priority shifting for resource allocation in systems with a shared resource, where higher priority implies better service. Priority schemes where priority levels are assigned fixed shares of the resource experience underutilisation if there are only low-priority tasks present. In these situations, lower priority tasks can be ‘shifted up’ to higher priority. This increases overall system utilisation and improves the service experienced by low-priority tasks. We present a shifting framework, study its properties and develop a Petri net model for a shifting algorithm. We analyse the model in order to identify situations where shifting of priorities is beneficial

Cooperative Positioning with MagicMap

... positioning system developed at the Humboldt-University in Berlin. While most other positioning systems are limited to specific scenarios and technologies our system provides means to incorporate any available wireless networking technology. Currently, MagicMap supports WLAN, RFID, and ZigBee as wireless technologies for positioning and Linux, Windows, and Windows CE as platforms. Position calculation and exchange is based on a cooperative approach allowing an open internet community to share the required data