Research And Implementation Of A Regional Discovery Service System For IOT Information Based On EPCIS

In the circumstances of EPC(Electronic Product Code) network, how tolocate the address of EPCIS(EPC Information Service) repository throughEPC and get all IOT events information about certain EPC is an urgentproblem.The discovery sevice which is raised by EPCglobal is a feasible wayto solve this issue. But there is only a draft about the global discovery service,the implementation is still under developing by EPCglobal.Under thebackground and the requirements of a practical project which is building alogistics cloud platform in a province, this paper disusses about how to designand develop the regional discovery service based on EPCIS, the EPCISrepositories are deployed in the companies or in the organization in differentareas.According to these issues, with the deep analysis of the requirements andthe related technology, this paper discusses about the architecture of thediscovery service which is deployed centrally, the cache mechanism of thediscovery service and the storage of Event Mapping Object. Based on abovethoughts, the design and the implementation of a prototype of the regionaldiscovery service based on EPCIS are proposed.This paper has the following content:(1)By referring the architecture of EPCglobal, this paper raises a solutionof the regional discovery service based on master/slave architecture.Theserver of the discovery service is deployed in the administrative center of theregional area(ex.the provincial level) while the EPCIS repositories are distributed among the companies or the organizations. Once the event objectis stored in the EPCIS repository, IS-Agent which is deployed in the EPCISrepository will get the event mapping object through the interface of EPCISand send it to the discovery service immediately. This discovery servicesupports two kind of query of EPC related event object. One is instant query,the other is standing-by query. About the instant query, the discovery servicefirst accepts the request of some certain EPC from the end user, then matchesthe event relation mapping objects which is stored locally to get the address ofEPCIS which contains the certain EPC, finally, the discovery service querythose EPCIS repositories and returns the event object list to the client. Aboutthe standing-by query, the discovery service first stores the EPC which comesfrom the client into the tracking query filter table, then the discovery servicemonitors the datas which are sent by the IS-Agent in the EPCIS repository,once an item matches the filter table, the discovery sevice will send a query tothis EPCIS and return the event object to the client immediately.(2) For the increasement of the query efficiency. This paper designs acache mechanism which is fits for the discovery service.With the cache model,the discovery service first query the cache item which is frequent accessedrecently, then send the latest time stamp of the cache item to the EPCIS,IS-Agent will response to the discovery service with the event object whoserecord time is later than the latest time stamp. Based on LRU cachereplacement algorithm, this paper discusses the concept of EPC dependencyand raises the LDRU(Least Dependency Recently Used) cache replacementalgorithm. It has been proved that with the cache mechanism in discoveryservice, the query efficiency has increased by27.5%through the test.(3)Based on the work above, the regional discovery service (REDS)based on EPCIS is developed, it contains the unify query interface, cachemechanism, EPCIS node management, IS-Agent, event object integrationservice and the data transport interface.With the function and the performancetest, it proves that REDS works well and effectively.