Analysis: 75 Case Studies of Active RFID in Action
By Dr Peter Harrop
In an analysis of 75 Active RFID case studies from 18 countries by IDTechEx, the largest number of projects was in logistics which had around twice the number of each of the nearest contenders - air industry, automotive/transportation and healthcare. In the case studies, the main items that were tagged were containers, followed by vehicles, conveyances and people, and this probably reflects the market as a whole. Car remote locking devices are products in their own right of course and do not tag anything. Tagging people is nonetheless a significant and growing sector.
The choice of frequencies narrows towards the higher frequencies as longer ranges are demanded, partly because of radiation laws. However, in many applications different frequencies are used to do exactly the same job, the choice apparently relating more to the suppliers’ preference than any proven economic or functional reason. Currently, 433MHz is the most popular frequency for active RFID, mainly driven by the preferences of car remote locking devices and military applications. Ultra Wide Band (UWB) and 2.45GHz are growing quickly.
Most of the case studies refer to ranges of up to five metres, closely followed by five to 30 metres but about 20 per cent are in the range 30 to 300 metres. Although a few companies have claimed to achieve up to a few kilometres range over the years, IDTechEx has yet to find any such systems in action. There are many reasons for the choices of range for active tags, including the fact that passive tags (with no power source of their own) cannot achieve the longer ranges. Short range avoids confusion between small things, medium range copes with vehicles and people, etc, passing through large constricted areas, and long range is needed to locate things at a distance using beams. Positioning using techniques such as triangulation is not yet common in RFID but geofencing (monitoring movement between areas by having interrogators at entry and exit points, as an example) is commonplace.