One recent article contrasting RFID and satellite tracking for cargo containers raised some interesting points. Unfortunately, instead of focusing on positive aspects of what satellite tracking could offer, it concentrated on making some fairly dubious assertions about the ‘faults’ of RFID. So, what is the truth about satellite versus RFID for Bulk container tracking?
Satellite communications that go beyond mere GPS information can provide information not only about the location of a container but also about its environmental conditions, whether it has been tampered with, and other useful data. What’s more, this can be achieved with in-transit containers virtually anywhere in the world. For some applications, such as tracking of munitions, hazardous materials, pharmaceuticals and other sensitive goods, having access to that kind of information in real time can enable the cargo’s owner to take immediate corrective action (if any is possible). For the majority of supply chain applications, however, access to this type of data at the point of receipt is perfectly adequate.
The issue isn’t whether satellite communications between a container and a head office can offer benefits in certain applications, the issue is that the article misstates RFID’s capabilities, costs and limitations with the intent of supporting the assertion that, “RFID is not good for global supply chain usage and satellite is good. In fact, RFID usage is actually dangerous for applications in US seaports.” The article’s review of the benefits of satellite is sketchy at best. The major support for its premise is based on a biased and, in some cases, untrue evaluation of RFID.
The article states that RFID cannot be used globally because there is no worldwide agreement on frequencies and hasn’t been authorised for use in countries such as China. While true in some measure, the article overlooks the inconvenient and obvious fact that all major international trading countries including Japan and China have approved active RFID products operating at 433 MHz that are based on ISO 18000-7 standards. The global RF community is moving to authorise the common HF, UHF and microwave frequencies to enable RFID usage around the world. The frequency differences cited in the article apply to UHF, not in 433 MHz active tags. And, in any event, UHF systems are capable of handling those differences.
The assertion that fixed location antennas might be difficult to place because of legal and operational issues is unsupported in real world application. Yard and port operators are installing various RFID reading systems to expedite shipments in and out of their facilities and to provide a value-add service to customers. Mounting readers on cranes and at certain locations at ground level address many reading needs. Readers on cranes and tugs can also provide absolute linking between container movement and the equipment or operator.
Timeliness & features
It is true that RFID typically works by having goods and containers move past a reader and that RFID data logging and e-seals offer historical data. Satellite can transmit the occurrence of unwanted events in a far timelier manner. In some instances, this can trigger urgent, necessary responses. In other instances, however, having this data go from the container to a head office isn’t a particularly efficient or even necessary scheme. Sometimes, having the container communicate directly with, say, the driver of a truck, is more efficient. If a refrigeration unit on a trailer fails, the driver, not the main office in some other state, is going to have to take corrective action.