Guide · DECT
Why DECT beats Wi-Fi handsets
A point-by-point breakdown: radio frequencies, security, battery life, roaming, fault tolerance, density, compatibility. With numbers, no marketing.
Frequencies & interference
DECT operates at 1880–1900 MHz (Europe & Russia) — a dedicated spectrum, no interference from Wi-Fi, Bluetooth, microwaves, neighbor APs. Wi-Fi phones share airtime with laptops, employee smartphones, IoT devices, guest networks — in a real 50-person office Wi-Fi airtime is saturated.
Security
DECT channel is encrypted at the hardware level (DECT Standard Cipher with 128-bit key from GAP 6.0). Eavesdropping the air is practically impossible without physical access to the base. Wi-Fi phone: encryption depends on WPA2/WPA3 config. Weak AP password or legacy WEP — your calls are in the air. Plus DECT handsets don't roam onto neighbour APs like smartphones do.
Battery
Typical DECT handset: 12–20 hours talk, 200–300 hours standby. Wi-Fi handset: 4–8 hours talk, 80–160 hours standby — because of a more powerful radio and a color display. A 2–3× difference. For a 12-hour shift it matters — a Wi-Fi phone may not last the day.
| Model | Talk | Standby |
|---|---|---|
| Gigaset SL800H PRO (DECT) | 15 h | 300 h |
| Gigaset R700H PRO (DECT) | 13 h | 320 h |
| Polycom VVX Wi-Fi handset | 6 h | 100 h |
| Spectralink 8440 (Wi-Fi) | 8 h | 160 h |
| Ascom i63 (Wi-Fi) | 5 h | 80 h |
Roaming & handover
DECT has standardized seamless handover (GAP, NG-DECT). The handset switches between cells in <50 ms — the call does not drop while walking through the office. Wi-Fi: handover between APs is a pain even with 802.11r/k/v. In practice you get 1–3 second drops when roaming, re-registration, sometimes call drops.
Capacity
One DECT base (cell) supports up to 8 simultaneous calls in the 1880–1900 MHz band. For a 200 m² office with 50 employees 3–4 Gigaset N870 bases are enough. Wi-Fi: 1 AP with 802.11ac for 50 clients in reality supports 10–15 voice flows parallel to data. More APs — more interference — degradation.
Resilience
Wi-Fi controller failure — all Wi-Fi phones and softphones are down. DECT bases work autonomously: when the Gigaset N870 central controller fails, cells keep serving registered handsets. SIP server failure — internal calls between DECT handsets within the same cell keep working.
When a Wi-Fi phone is still better
If the employee constantly moves between geographically distant offices — a Wi-Fi phone with a softphone on a smartphone is more convenient. If you need video on the phone — Wi-Fi (DECT is voice only). If the entire infrastructure is built around unified communications (Microsoft Teams, Cisco Webex) — a Wi-Fi phone is more logical there. In all other cases — DECT.