The identification process is initiated by the smart spaces identification service application towards the RFID reader system (step (1) in figure 2). The master reader takes the responsibility and wakes up the slave readers and tags in its radio range (step (2)). The slave readers proceed in the same way (step (3)) and wake up the tags in their range, if those are not yet woken up through the master reader's first wake-up call. The slave readers and the tags send their identification information to the master reader (step (4)), which collects and removes the redundant information and sends it finally to the smart spaces object server for further processing (step (5)). The duplicated redundant information from the tags is used later for fault-tolerance and localization of the tags. The slave reader could theoretically take more responsibility in tag information processing. But the intelligence in the slave readers is determined by the cost and complexity restrictions. In addition, the system can support RFID services initiated from mobile devices with and without embedded RFID reader capabilities. There are four possibilities: