1. What a smart lock sends over cellular
A smart lock uses cellular for remote unlock, temporary codes, unlock logs, and battery alerts. It fits long-stay apartments, short-stay rentals, hotels, and offices, where stable Wi-Fi is often missing. The PMS (property and hotel management system) syncs room status, check-in, and check-out. A temporary code can turn on and off with check-in and check-out. SimtoLink supplies NB-IoT and 4G to lock makers and apartment operators, with a data pool and an API into the PMS and short-stay platforms.
2. Apartments, short stays, hotels, and homes
Locks cover apartments, short stays, hotels, and offices. Unlock latency, battery life, and cost differ by site:
Long-stay apartments
Apartment locks need remote authorization, self check-in for the tenant, and a remote clear of codes when the tenancy ends. NB-IoT or 4G gets the unlock command out in time, typically 10–30MB a month.
Short-stay rentals
A short stay needs a temporary code that turns on at check-in and off at check-out. 4G keeps unlock latency low and can link to platforms such as Meituan and Tujia.
Hotels and offices
Hotel rooms and office doors need a link to the PMS and the attendance system. 4G handles many unlocks at once and live logs.
Home smart locks
Most home locks use a gateway or Wi-Fi. A model with its own SIM can use NB-IoT for a long battery life, at only a few MB a month.
3. What the lock link has to cover
- No stable Wi-Fi: Apartments, short stays, hotels, and offices often have none. Cellular gets the unlock command out in time and keeps room status in sync.
- Unlock latency: Temporary codes and remote unlock need low latency. A short-stay code has to take effect on its own at check-in and check-out, and 4G keeps that live.
- Unlock log: Unlock events and battery alerts have to be reported, so the trail is traceable and the locks can be maintained.
- Battery and power: Home locks usually run on a battery. NB-IoT draws little power and fits a long life. Apartments and hotels can use mains power, where 4G fits many unlocks at once.
- Platform link: Connect to the PMS and short-stay platforms, for room status, check-in and check-out, and a closed API loop.
4. Which SIM fits which lock
Unlock latency and battery life differ by site. Use the table as a starting point:
| Use | Recommended network | Why it fits |
|---|---|---|
| Long-stay apartments and short stays | 4G | Temporary codes and room-status sync; low latency |
| Hotels and offices | 4G | Many unlocks at once, and a PMS link |
| Home smart locks | NB-IoT / 4G | Infrequent unlocks and a long battery life |
5. How much data a lock uses
One lock typically uses about 10–50MB a month, depending on how often it opens, how often it reports, and OTA. NB-IoT fits infrequent use and a long battery life. 4G fits busy apartments and hotels. Pool SIMs by site type and keep 20%–30% spare.
6. Security for the front door
Entry is sensitive, so treat the link as high security. Sessions need TLS, a private APN, and an IP allowlist. SimtoLink provides the private APN and completes real-name registration for the SIMs.
7. What SimtoLink would put in the lock
For home locks and infrequent unlocks, use NB-IoT. For apartments, short stays, and hotels that need live room-status sync, use a 4G IoT SIM. NB-IoT draws little power and fits a battery. 4G fits many unlocks at once. SimtoLink plans for 99.9% network availability, a data pool, and an API into the PMS.
8. Fitting locks across a portfolio
Rollout:
Pick the SIM by site—apartment, short stay, or home—and check signal in the target building. Set the APN and IP allowlist, and alert at 80% of the data allowance. SimtoLink stays with the project from the first building through the wider portfolio. Contact us for a plan built around those locks.