Radio Frequency Identification

There exist several technologies serving the same purpose of quickly and accurately capturing data. The key automatic data collection technologies include bar coding, magnetic stripe, radio frequency data communication, radio frequency identification, voice data collection, machine vision, optical character recognition, and smart cards.

Bar coding is an industry standardized symbol consisting of bars and spaces of various widths that are read by optical scanning devices. The width and position of the bars are actually coded combinations of numbers, letters or punctuation, used to "identify the item, its producer and any other piece of information necessary to control its movement".1 (Anonymous, "Industrial Engineering's 1992 Automatic Identification Buyer's Guide". Industrial Engineering, p.BG1) The item is scanned, all its data is transmitted directly into a computer via electrical impulses, generated from light reflections from the bars and spaces. The impulses are measured by a decoder, translated into binary code then transmitted to the computer. This technology is optimal for rapidly moving items commonly found on conveying systems within the retail and manufacturing arenas.

Magnetic stripe technology however, was initially instituted by the financial services industry to identify accounts and as a means of security. The magnetic stripe records greater volumes of information than many of the other aforementioned technologies, including bar coding. It provides a flexible format, with higher durability, and is highly secure. Data is encoded using electromagnetic charges that are read by a decoder, translated into numbers and letters, immediately identified by the computer. This technology is currently being applied to employee ID badges, debit cards, boarding passes for commercial flights, filling stations and some manufacturing applications. Future technical refinements include increased data storage on the magnetic stripe, resistance to extraneous magnetic fields and improvement of readers to process dirty or damaged magnetic stripes.

Radio Frequency Data Communication (RFDC) systems consist of battery operated wireless computer terminals, connected by a radio link to a main computer. Typically these hand-held terminals transfer real-time data from the shop floor, where the data is collected, directly to the mainframe computer. The devices utilize spread spectrum radio communication, which as the name implies, spreads the signal over a wide range of frequencies therefore ensuring "the signals are received, even if exposed to interference."2

(Anonymous, "Industrial Engineering's 1992 Automatic Identification Buyer's Guide". Industrial Engineering, p.BG6)

Radio Frequency Identification (RFID) tracks objects via an attached ID tag that sends and receives radio signals. The three components of RFID, a transponder (ID tag), an antenna and a reader operate in tandem as an electronic label. The antenna-equipped reader will transmit a signal which activates the tag, at which point the object's data is read and sent directly to a host computer. Some systems offer more than identification of the object, they have writing capabilities that can add or delete information to or from the ID tag, thereby creating a 'portable database'.

Data entry into systems can now be processed through voice technology, useful when the operator is unable to key in the data manually on a keypad. This technology allows the operator to speak the information into a microphone, using words from a pre-programmed language, which the system recognizes and converts to electronic impulses that are immediately processed by the host computer. As technology evolved to recognize voice commands, an imaging process, utilizing machine vision (MV) equipment can scan ID codes, objects or documents and interpret what it sees. Used mainly in industrial environments, it is more diverse than bar coding, as it is capable of restoring damaged codes and scanning in low contrast applications. Optimally this equipment is being used in manufacturing inspection areas, to validate component dimensions, positions or other structured type tasks. Similarly, optical character recognition (OCR), reads two-dimensional numbers or letters that are scanned by a light source then transmitted to a computer through electronic impulses. Using this symbol based system is 'excellent for applications where labels must be read by both humans and machines'.3 (Anonymous, "Industrial Engineering's 1992 Automatic Identification Buyer's Guide". Industrial Engineering, p.BG12)

One step beyond technological systems where equipment scans an identification code, a smart card uses an embedded microchip to carry large programmable databases. These cards, having the information storage capacity of a PC can distinguish between multiple services as well as provide security. One card could, potentially be used as a bank card, grocery club card and health card.

Any of the automatic data collection technologies discussed function optimally when integrated systemically throughout an entire operation or organization, resulting in shared information that increases productivity and reduces costs. In the current corporate environment, optimization of the manufacturing processes using emerging technologies also leads to increased accuracy and throughput, which ultimately drives an increase in sales and cost reductions.

In the warehousing field, consideration to radio frequency technologies, in particular, can increase competitiveness through total product cost reduction, increased accuracy, less paperwork, savings due to rapid invoicing and higher quality of customer service, in terms of reduced lead-times and availability of goods. Radio frequency systems have been used since the early 1980's as a tool to obtain these advantages. There are three distinct types of radio frequency transmission technologies, narrow band, direct sequencing spread spectrum and frequency hopping spread spectrum. All have specific strengths and weaknesses and are appropriate in distinct environments. Narrow band transmission has a limited band width that transmits on its own channel with less interference, which requires governmental authorization, but offers increased power to cover a greater area. Conversely, spread spectrum technology has a greater band width, no channel exclusivity, can hold more information, requires no governmental licensing, but with a significant lower power level it only covers about one third the area of narrow band transmission. Many warehouses are reluctant to implement either type of RFID given the costs and the difficulty in evaluating its advantages. RFID should reduce costs by saving on resources (computer space, personnel and time), while