IS541.1: The world’s first 5G 450 MHz smartphone for Zone 1/21 enables mission-critical communication in potentially explosive atmospheres

Lauda-Königshofen, 16 June 2026. i.safe MOBILE is presenting its latest development at Critical Communications World (CCW) in London from 16 to 18 June 2026 at Stand J20: The IS541.1 is the first explosion-proof 5G smartphone with 450 MHz support for use in Zone 1/21. The device combines critical communication with the highest operational reliability and is approved for mission-critical use in potentially explosive atmospheres. 

Communication without restrictions – even in emergency situations

Critical infrastructure, energy suppliers, industry and public authorities face the same requirements: reliable, independent communication even when public mobile networks are overloaded or down. This is made possible by the dedicated 450 MHz network. With the IS541.1 from i.safe MOBILE, this network is now available for use in Zone 1/21 environments.

450 MHz: Range and resilience for critical infrastructure 

The 450 MHz band offers physical characteristics that set it apart from conventional mobile networks. Low frequencies ensure long range and optimal building penetration. The mobile network enables highly available, autonomous and blackout-resilient communication for mission-critical applications such as control, monitoring and crisis management in sectors like energy, water, transport and public administration. Around 40 commercial networks are in operation worldwide in the 450 MHz band.

The IS541.1 supports the frequency bands of the 450 MHz band and, in addition, a broad global spectrum of all relevant bands for 2G, 3G, 4G and 5G networks.

 The 5G smartphone builds on the proven platform of the IS540.1. The replaceable 4,400 mAh battery enables continuous shift operation, as spare batteries can be charged at any time outside the ATEX zone and inserted into the device. The 6-inch FHD display with Corning® Gorilla® Glass withstands the toughest conditions. Accessories such as PTT headsets or remote speaker microphones can be connected quickly and securely via the 16-pin ISM interface connector. Programmable function keys, including an SOS button, provide direct access to PTT communication and lone worker protection (LWP).

The IS541.1 is designed for a wide range of critical applications: from the energy sector through industry, mining and oil and gas to public safety and government agencies, as well as transport, retail and agriculture.

450 MHz Alliance 

i.safe MOBILE is a member of the 450 MHz Alliance, the international advocacy group for the promotion and further development of networks in the 380–512 MHz band. The Alliance brings together network operators, public authorities, equipment manufacturers and users worldwide and is committed to standardisation, regulation and global market development.

In Germany, 450connect builds and operates the nationwide, dedicated 450 MHz mobile network for operators of critical infrastructure (KRITIS). 

Availability

The IS541.1 is available now through the i.safe MOBILE sales network.