As is well known, radio waves cannot be contained within a selected space. Emitted radio waves are received by all receivers operating at a specific frequency that are within their range. Receivers pick up signals in a continuous mode and transmit them to a computer in the same mode for registration. The recording of the read stream must therefore be sensibly filtered, i.e., preceded by IT analysis that rejects redundant information. This function is performed by software located between hardware and software, i.e., middleware. This is a new level in the hierarchy of user IT often mentioned in the context of RFID, although the concept is not new at all. Successful implementation of radio data reading is primarily the implementation of effective software operating at many levels. Five basic levels of software supporting RFID reading can be distinguished:
Level 0 – hardware reading, programmed by the manufacturer of RFID equipment (printers and readers), inaccessible to the average user.
Level 1 – middleware acting as an intermediary between the reader and the application database. Its task is to transmit to the application database only those data that are relevant for their further processing. At level 1, only the EPC number (sometimes called a “radio barcode”) and possibly other information recorded and filtered in the buffer database are made available.
Level 2 – EPC-IS (EPC Information Service) software enabling users to exchange data identified by EPC codes and contained in local systems (WMS, ERP). The PML (Physical Markup Language) language is used here, similar to HTML or XML, allowing for the unified transmission of data about goods.
Level 3 – ONS (Object Naming Service) service software providing IP addresses of servers where the remaining data characterizing the identified product are stored.
Level 4 – application software such as WMS or ERP operating locally at the user’s site.
It is worth noting that WMS or ERP IT systems process the obtained data at a sufficiently high level, regardless of whether the data was read from barcodes or via RFID. At this level, the data is already saved in the ASCII standard (American Standard Code for Information Interchange – a computer code described in the ISO 646 standard, defining 128 alphanumeric and control characters, used for data exchange between computer systems).
In the RFID applications observed so far, data reading is mainly carried out at levels 0 and 1. The functionality of levels 2 and 3 is “temporarily” implemented by substitute technologies (via EDI or other agreed-upon descriptive data exchange). However, the functionality of level 4 does not depend on the data acquisition technique. Until levels 2 and 3 reach a stabilized stage, potential users are forced to look for other technologies that allow for the effective implementation of RFID.
The article comes from the magazine “e-Fakty” 5/2006.