Wireless technology provides a unique number for each item and a powerful means of tracking and tracing products RFID (radio frequency identification) is a wireless technology that uniquely identifies any product, carton or container as it moves from the factory to the end-user and beyond. RFID tags contain a microchip less than 1mm wide, combined with a wireless circuit and an antenna. When a tag is triggered by a wireless signal it responds by emitting an identifying number, which is used by a computer to update a record of that product, which can include its destination and complete specification. While the barcodes used for product ID often have to be scanned by handheld readers, RFID tags can usually be read automatically by static wireless readers, which cuts costs. And RFID can provide a unique number for each item, which provides a much more powerful means of tracking and tracing products. The United States Department of Defence has used RFID for 15 years, and retailer Wal-Mart has asked its suppliers to fix tags to all products by the end of this year. The chief architect of RFID standards body EPCGlobal, K.K. Suen, said: 'Worldwide, high-value products most easily justify the cost of RFID and products with a wide range of models or specifications can benefit most. So industries such as electronics and fashion garments are strongly interested.' He said interest in the technology was strong in Hong Kong, but most companies were in the learning phase. 'As would be expected, big logistics companies are doing trials, but otherwise most pilots result from overseas buyers demanding RFID use.' The most common type of RFID tag is a passive device which has no batteries and uses the wireless energy of the reading device to power its identifying signal. The information sent may be limited and the range may be around 2.5 metres. The cost per tag is about HK$1.50. Passive tags are often mounted in transparent plastic, self-adhesive labels, including a metallic printed antenna, and fixed to product packaging. Much more expensive active RFID tags have a battery and transmit continuously over a range of 100 metres, which makes them suitable for use on containers or other large-scale objects. Information transmitted can be two kilobytes, which enables some security features. Battery life may be one year, but semi-active types that only transmit when they receive a wake-up call from the reader have a battery life of years. Wireless waves are greatly affected by the environment, and this affects the accuracy with which passive RFID tags can be read. Luk Bing-lam, senior engineer at the RFID facility at City University, said: 'The first generation of tags had a reading accuracy of 80 per cent, but a figure of over 90 per cent can now be achieved. 'The way the tags are attached is important, because a metallic product can reflect radio waves, while liquids, such as foodstuffs or cosmetics, can absorb them. Temperature and humidity affect performance, as does the orientation of the antenna to the reading device.' RFID readers may also be affected by mobile phones, wireless LANs and many other wireless sources in use. To achieve a high reading accuracy, engineers must study tag design, attachment and ambient conditions and make improvements. However, even successful RFID applications are generally backed up by barcodes and manual operators with portable reading devices to identify items when automatic reading fails. Craig Jo, business development director at Hong Kong RFID, an RFID equipment supplier, said passive tags were not a mature technology for supply chain use. 'Most Hong Kong suppliers are waiting for Wal-Mart to ask for RFID tags, otherwise, they will not use them. Wal-Mart is using tags at the pallet or box level, but not the item level.' Wal-Mart was a pioneer in barcode use 20 years ago and had invested a lot in RFID, Mr Jo said. Most profitable RFID applications used active tags to locate high-value equipment or people, he said. Other parallel applications include the use of active RFID on wrist bands to locate VIPs at the Hong Kong Convention and Exhibition Centre, and a similar application to locate staff and mobile equipment at a hospital.
