You have 100 devices, each on a 10GB/month plan. Month-end: 30 used only 3GB, 20 maxed out 10GB, the other 50 averaged 4GB. Result: you paid for 1000GB but actually used ~450GB. The wasted 550GB is exactly what a data pool fixes.
How a data pool is actually billed
- Instead of per-SIM monthly plans, you buy one 'pool' (e.g. 600GB/month).
- All 100 SIMs share from this pool — whoever uses more or less is fine; you're billed on total actual usage.
- Unused pool isn't refunded, but you only pay extra if you exceed it — so sizing the pool right is the key.
The math with 100 SIMs
- Separate plans: 100 x 10GB = 1000GB capacity, 450GB used, pay 100% (55% wasted).
- Data pool: size a 600GB pool from the 450GB actual plus headroom; utilization jumps from 45% to near 100%.
- Same actual usage, the bill usually drops ~30% (depending on carrier unit price and headroom).
A data pool isn't universal
- Too few SIMs (<20) isn't worth it — management cost outweighs the gain.
- If usage is perfectly even and everyone maxes out, the pool has no advantage.
- A SIM with sudden spikes (e.g. temporary HD livestream backhaul) drains the pool instantly — keep separate headroom.
A data pool doesn't cut unit price — it cuts the half you'd never use. More SIMs, more uneven usage, more you save.
FAQ
What's the difference between定向 and full-roam data SIMs?
定向 SIMs are limited to a designated APN/app and are cheap; full-roam SIMs use public networks—wider coverage but costlier.
How is IoT SIM real-name verification done in Vietnam?
Vietnamese carriers require business/personal verification; bulk devices are managed via a CMP platform.
How do you manage the M2M SIM lifecycle?
Covers activate/suspend/deactivate/recover; use a CMP console to monitor traffic and status remotely.
Should I pick 4G or 5G SIM?
Depends on device and coverage; most CPE/pocket WiFi use stable 4G, 5G when coverage exists and high speed is needed.