ERMES is a pan-European radio paging system. Radio paging services depend on the allocation and availability of appropriate frequencies in order to transmit and receive between fixed-base stations and radio paging receivers respectively. European Telecommunications Standard Institute (ETSI) has developed the European Telecommunications Standard ETS 300 133 for ERMES operating in the frequency band 169.4125-169.8125 MHz.

ERMES failed to develop and its frequency band has been reassigned to different use.

Technical specification

Transmission parameters

• ERMES transmits the data at 6250 bit/s.
• ERMES uses Frequency Shift Keying (4-FSK) modulation.

Transmission parameters, pager interrogation

• Each paging transmission is divided into 60 cycles of 1 minute in length.
• Each cycle is divided into 5 subsequences of 12 seconds.
• Each subsequence is further divided into 16 batches, labeled A through P.

Pager interrogation

• The pager population is divided into 16 groups.
• Each pager group is allocated to one of the 16 transmission batches [A...P].
• The pager needs only to be active during the period it has been allocated to, allowing it to go into sleep mode 15/16 (~=93%) of the time (a ~7% duty cycle). This scheduling allocation protocol extends the battery life of the pager by several orders of magnitude.

Related websites

• PDW Paging Decoder freeware
  Freeware
  Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...
  
  
• Audio samples including ERMES, GOLAY etc...