When a multitude of RFID tags are in the interrogating field, an anti-collision technology must be used. In literatures, the reading performance was mainly investigated on the error-free communication links between reader and tags. In the practical situations, particularly where a number of readers and other wireless devices share the same frequency band, the performance on the erroneous links would be significant interest. In this paper, we evaluated Gen2 Air Protocol paying attention to the anti-collision performance in random error communication link. As a result of simulation, two findings were obtained. Firstly, there is an appropriate number of slots depending on the number of tags. This number hardly changes even if a random error is incurred on the link. Secondly, the singulation speed might be significantly degraded particularly in erroneous links, if the optimal number of slots is not chosen. The findings can be interpreted such that the necessary link quality can be derived if the number of tags and permissible time are known a priori to the implementation. For instance, if 64 tags are required to be read in one second, it is necessary to ensure the link quality to be better than BER=10 −4 in random error environment.

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RFID attracts attention as a useful device in locationaware application. SPEARS WG of WIDE Project had already developed a system [2], which uses RFID devices as a sensor of human's location. Purpose for this system is to provide the service based on a user's location in a conference. In this system, the model in which location of user is gathered and provided per each user was adopted. This paper describes several areas of problems and improvements in our latest implementation. The following functions were implemented by the addition of a system called "Area-d": 1) provide a service tied with a location, and 2) provides users' communication rendezvous service. These functions are able to add to the existing system without altering the existing model. This paper describes a location-oriented data processing model and applications.

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