Distributed discovery services via EPC-BGP for mobile RFID

In this paper, we propose an extended architecture of the EPCglobal network that allows tracking objects. This architecture makes use of the distributed discovery services along with the EPC-BGP to provide detailed information about an object regardless of its location. In the EPCglobal network, each object is assigned an IPv6 address once it leaves the last gateway in the supply chain. The IP address of the last gateway enables backtracking of all the information about this object throughout the supply chain. To this end, EPC status updates are crucial in order to advertise any changes in the EPC into the supply chain. On the other hand, concurrent EPC updates, expired EPC databases and/or limitation of resources may cause blocking of an EPC update request. Therefore, we evaluate our proposed architecture in terms of blocking probability of the EPC update requests. To this end, We define three types of blocking, namely the Justified Update Blocking (JUB), Unjustified Update Acceptance (UUA), and Unjustified Update Blocking (UUB). We investigate the impact of the frequency of update advertisements on the blocking probability. Numerical results confirm the trade-off between blocking probability and communication/computation overhead due to EPC update messages. However, further investigation in terms of the number of advertisements and the distance between the routing tables confirms that advertisement of EPC update messages based on certain thresholds can overcome this trade-off.