The NB IoT network enables us to offer everything a typical keycard system used in offices and hotels does, but without wires. Most keycard systems used in offices and hotels are usually wired together and connected to onsite servers/computers. This wiring is usually in the hollows of doors, or in walls and ceilings and goes all over buildings. The locks need to be connected to each other so a computer can tell a specific lock at anytime to only accept a specific keycard for a specific person for a specific time. Anyone who has ever stayed in a hotel, and seen the reception staff type into a computer, and then swipe a keycard through a device, or wave it over a device is simply programming the lock to accept your card for the duration of your booked stay. And everytime you swipe your keycards, the lock has to check with the computer to see if your card is authorised for that lock, and if it is, then it lets you go in.
We add NFC to our smart access system, so that our system can be used in exactly the same way as a keycard system, but the main difference is that instead of using an onsite computer and a special device to program the NFC keycard (called an encoder box), we can program the card with a smartphone app with NFC (most Android phones include NFC). And when we add NFC, we don't have to use the NB IoT network everytime someone wants to unlock the door - we just use the NB IoT network once to program it to accept that NFC keycard for a chosen time. The lock doesn't need to go back everytime to a computer to check if the card is authorised, because there is already a tiny computer in the lock that already knows what card is authorised after the initial programming done over the NB IoT network.