An alternate to RFID

Apr 1, 2007 12:00 PM, By Dave Plank

The gripes about traditional radio frequency identification have become well known: It doesn't work well around water; it doesn't work well for tracking metal objects; and it doesn't work well in extreme climatic conditions. Also, active tags are pricey, with limited range and shorter-lived batteries than many applications require. As a result, the market for such devices hasn't grown as quickly as some predicted five or six years ago.

While traditional RFID isn't going anywhere (see graphic), enterprises with more exacting demands soon should have another arrow in their quivers: RuBee, as its creators have dubbed it, or less whimsically, IEEE 1902.1. The protocol is in the final stages of development by the standards organization, and regular shipments of 1902.1-enabled devices should begin late this year, according to officials at Visible Assets, the Miami company that developed the technology.

RuBee (named by its makers, diehard Rolling Stones fans, after the song “Ruby Tuesday”) is a peer-to-peer radiating system that operates below 450 kHz, often around 132 kHz. The low frequency — HF RFID typically operates around 13.56 MHz, and UHF around 915 MHz — means RuBee functions in harsh environments and has a range of 10 to 100 feet. It also functions well around steel and water and can be “seen” around corners. These traits make it suitable for use in heretofore RFID-free environments such as agriculture. But it also should work for less obviously harsh uses, such as tracking steel containers inside larger steel containers surrounded by water, e.g., cargo ships. RuBee networks already have been deployed on so-called smart shelves to track high-value equipment in hospitals and operating rooms and in stores and warehouses for automatic inventory tracking.

RuBee's advantages stem from the fact that conventional RFID tags, active or passive, primarily use radio waves to transmit a signal. RuBee tags, however, primarily use magnetic waves, which are unaffected by water, as radio waves are. Lower frequencies also are less affected by metal, and low-frequency chips are significantly cheaper and require less power, prolonging battery life. The lithium cells powering current RuBee tags can be expected to last 10 years, Visible Assets claims.

But there is a downside. Because lower frequencies have much less bandwidth than higher frequencies, only six RuBee tags can be read per second; in contrast, dozens of HF and hundreds of UHF RFID tags can be scanned in that amount of time.

However, RuBee's boosters say the lower number of scans per second isn't a problem. In fact, they don't consider RuBee to be a “tracking” technology at all, preferring to call their product a “visibility system.” Tracking devices simply collect data on where an object has been, as that object moves through portals. In contrast, RuBee devices provide real-time information on the status of objects. For instance, in a RuBee smart shelf system, readings can be taken at a user-defined interval in order to determine when objects are moved. An audit trail is created automatically.

These differences explain why RuBee may not turn out to be an “RFID killer,” as some early hype called it, but rather a complementary technology that works alongside RFID, or in applications RFID simply can't handle, according to Michael Liard, research director for RFID at ABI Research. As such, RuBee may offer a boost to the RFID market, which hasn't matured as quickly as some had hoped or predicted.

“The [RFID] market as a whole has lagged in the last twelve to twenty-four months, as retailers haven't adopted systems as quickly as they were expected to,” Liard said. “RuBee could complement RFID in systems where it is necessary to create an audit trail. These would be more exotic markets and uses than RFID currently serves.”