European radio messaging services (mobile communications) (ERMES)

European Radio Messaging Services (ERMES) is a standardized(ETS 300 133) pan-European paging service with 16 channels in the 169 MHz band. The introduction of Ermes was decided by the CEPT countries in 1986, with the number of frequencies to be used depending on the further expansion of the European network.

The aim of Ermes is the Europe-wide use of a paging system with a uniform radio interface. Ermes should be able to support a high number of subscribers. It is assumed that there will be 32 million subscribers per country, which can be served by up to eight network operators per country. Compared with other paging services, Ermes is to be equipped with considerably more features. Likewise, the number of call classes from tone-only, numeric and alphanumeric will be expanded to include pan-European paging via roaming, message numbering and group calling. Additional services include call forwarding, destination call, message storage, multiple addressing, call charge information, call blocking, call repetition and 64 kbit/s data transmission.

The radio interface uses PAM and frequency modulation( FM) with four signal frequencies. A total of 16 channels with a channel spacing of 25 kHz are available in the frequency range between 169.4 MHz and 169.8 MHz. The coding is equipped with error correction methods, and the transmission protocol supports TDMA and FDMA.

Ermes is intended to complement Eurosignal - offered in Germany by Deutsche Telekom - with additional features such as transparent data transmission(call class 3) and is to be offered in all CEPT countries. Ermes has been in operation since 1993. The system offers all call classes, has roaming and can transmit 400 characters per radio call at a speed of 6.25 kbit/s.