While the increasing adoption of RFID has driven the costs down lot, an RFID system can still be quite expensive to implement. With this in mind, choosing the right technology for the application is vital to ensure an adequate ROI (Return on Investment).
The technology (operating frequency and standard) you choose has the biggest influence on the cost. In any given technology, the workload for the system to operate properly is divided between the reader and the tag. Usually, the simpler the tag is, the most complex and sophisticated the reader must be - and this easily translates in the "cheap tag, expensive reader" rule of thumb.
Even taking into account the cost distinction between passive, semipassive and active tags, in general the level of sophistication required to read passive tags calls for more expensive readers, while with active tags the cost of the reader is much lower. So, when "designing" your system, one of the first things to take into account is how many tags you will need - and if you can reuse them in some way. Also, consider the unit price for a tag is strongly dependent on the quantity - the most cost effective option is often to buy an entire roll.
With regards to the frequencies, LF is the cheapest technology, mostly because it is the oldest one and has a more widespread use - car immobilizers come to mind, calling for large volumes and very cheap readers.
HF comes second, while usually UHF passive readers are the most expensive in the lot.
With regards to standards, widely used standardised technologies are usually much cheaper than proprietary technologies. This partly due by the fact they are in general sold in larger volumes, but also that you can buy both tags and readers from different manufacturers. This, as often does in other sectors, opens up free market competition. A related advantage is that this gives you better guarantees about how long a particular technology will be available on the market, and allows you to change your suppliers every time a cheaper or improved version becomes available.
Once you have chosen the technology, other factors that can affect the cost are:
- The tag packaging: when you buy a tag, it can be supplied with different substrates or packaging, ranging from a cheap tag on a sticky substrate (label) to more expensive tags encased in various material to work in harsh environments or to extend the lifespan;
- The reader portability: do you need fixed or portable readers? Fixed readers are usually more powerful (longer range/accuracy) and cheaper than the portable counterparts;
- The reader ruggedness: if your application is meant to work outside or in dusty environments you will need a ruggedised reader, able to withstand harsher condition. However this will obviously have an implication on the cost of the reader.
Lastly an important consideration is to keep in mind that an RFID system does not just include readers and tags. For most applications, you will need to acquire the entire infrastructure to go along with it (computer, servers, backup system, software cabling etc) - and the cost of the latter can easily largely outweigh the cost of the RFID technology used in the system!
