North China University of Technology, Beijing (CHINA)
Central Michigan University (USA)
CADP (Construction and Analysis of Distributed Processes)
EPCglobal published a framework for developing applications of
Electronic Product Code (EPC) network in 2005. In order to leave
flexibility to it user, it only gives a series of interfaces for
implementation. The Application Layer Event (ALE) is one of the
interfaces through which clients may obtain filtered consolidated EPC
data from a variety of Radio Frequency Identification (RFID) readers.
The objective of ALE is to reduce the volume of EPC data that comes
directly from RFID readers into applications. The processing done at
this layer typically involves: (1) receiving EPCs from one or more RFID
readers; (2) accumulating data over intervals of time, filtering to
eliminate duplicate EPCs and EPCs that are not of interest, and
counting and grouping EPCs to reduce the volume of data; and (3)
reporting in various forms.
EPCglobal provides an API to facilitate development of ALE applications. The API specifies the atomicity property constraint by a case study while leaving the flexibility of implementation up to the developers. An important issue the developer has to deal with is the atomicity property of event cycle. That is, an event cycle is treated as a single atomic unit and proper handling failure of a read cycle (as part of an event cycle) is critical. If a read cycle failed the EPC data will be lost according to EPCglobal standards. So there is no way to undo a completed operation and reverting the system back to its previous state. To remedy this problem, a fault tolerant strategy is proposed, based on a new architecture for ALE with respect to fault tolerance and design several algorithms implementing the poll method of the API.
Two polling modes (synchronous and asynchronous) and three algorithms for the poll method were proposed and described formally in LOTOS. Successful termination of transactions in the two polling modes was expressed as a temporal property in regular alternation-free mu-calculus, and was checked on the LOTOS specifications using the EVALUATOR model checker of CADP.
As a key component of EPC framework, ALE plays an important role for
the reliability and performance of EPC applied systems. The new ALE
architecture proposed increases its reliability, and the separation
between fine-grained cycle and coarse-grained event cycle, EPC network
channels can be released to prevent traffic block. The formal analysis
using LOTOS and CADP has shown the effectiveness of the proposed
Jing Sun, Huiqun Zhao, Wenwen Wang, and Gongzhu Hu.
"Atomicity Maintenance in EPCreport of ALE".
Proceedings of the 10th IEEE/ACIS International Conference on Computer
and Information Science ICIS'2011, pages 224-229, IEEE Computer Society
Available on-line at: http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6086474
Prof. Gongzhu Hu
Computer Science Department
Central Michigan University
Office: 115 Pearce Hall
Mount Pleasant, Michigan 48859
|Further remarks:||This case study, amongst others, is described on the CADP Web site: http://cadp.inria.fr/case-studies|