Near Field Communication (NFC) is growing in consumer recognition, but it remains strongly associated with payment or transportation because of its roots in the smart card industry. NFC is, on the other hand, a potential IoT enabler because it responds to several concerns in an interconnected IoT environment.
First, a couple of fundamental points to keep in mind as you assess how you might use NFC. NFC is a short range (proximity) technology, broadcasting only up to 3 cm. NFC involves a passive tag or “listener” device, which is powered by an active “poller” system such as a smartphone or card reader. NFC is a bidirectional channel capable of data rates up to 424 kbps. This is not extraordinary when compared to Wi-Fi, but it is certainly enough for many IoT use cases such as basic data collection and system control.
In the IoT, discretion will be key advantage of NFC. In a connected world where every-other machine or sensor will soon be broadcasting something, using Bluetooth, Wi-Fi and other longer range technologies will be like putting a sign on a door to your machine that any dishonest, malicious and just curious person might want to try to open.
The NFC listener, however only broadcasts when it is powered by the presence of a polling NFC device (a smartphone or reader). It is only powered when the poller is within 3 cm. This implies the physical presence of a user who has some knowledge of the machine and where the NFC interface is located.
We already have the experience in RF-crowded public environments where we can easily find dozens of Wi-Fi connections and ask ourselves, "Now what do I connect to?" With the large number of objects that will soon have local connectivity (whether NFC, Bluetooth, Wi-Fi or some other channel) in an IoT environment presents a real challenge for the end user. The is exacerbated because in the depersonalized nature of the IoT environment where objects are more likely to be identified with serial numbers as opposed to names like "Bob's Coffee House." In this complex, depersonalized IoT environment, how does a maintenance worker efficiently identify the one panel out of 20 that he is supposed to reconfigure and correctly associating the physical object with the RF connection in the list of Bluetooth devices on his smartphone? With NFC, the challenge is solved. The user simply approaches the smartphone to the NFC marking on the panel that he needs to work on. The smartphone wakes up the NFC interface, this component then wakes up and pairs other appropriate communication channels such as Bluetooth or Wi-Fi, which may be necessary. The maintenance user is sure to connect to the intended machine. There's no risk of inadvertently selecting the wrong communication channel and accidentally connecting to a nearby machine.
Low Power Consumption
Power consumption will be a second key advantage of NFC. Already the NFC listener has relatively low power consumption at less than 5 mA during communication. More importantly, the listener NFC device draws power from the poller and not from the system that it is installed on. The listener need not be powered at all in the absence of the poller. When used in combination with other RF technologies like Bluetooth or Wi-Fi, the NFC listener can detect the presence of the user’s smartphone, trigger wakeup of another interface like Wi-Fi and pairing of the system with the user’s smartphone Wi-Fi.
For all of these reasons, the IoTize design team implements NFC in the IoTize modules designed for local connection to an itinerant network. This resulted in our module, IOTZ-TAP exploring the use of an NFC only solution. The technology has been so convincing that it is now included in all road mapped IoTize modules as a complementary interface and as a channel for module configuration.