Data transmission systems

A DATA TRANSMISSION SYSTEM COMPRISING A PLURALITY OF RADIO STATIONS, EACH STATION INCLUDING A TRANSCEIVER WITH ASSOCIATED ENCODING/DECODING MEANS FOR TRANSMITTING/RECEIVING DATA, WHEREIN DATA SIGNALS ARE TRANSMITTED AS PACKETS INCLUDING ONE OR MORE BLOCKS OF DATA ENCODED WITH AN ERROR CORRECTING CODE, WHEREIN EACH STATION IS ARRANGED AUTOMATICALLY TO ISSUE A REQUEST FOR REPEAT OF A PACKET OF DATA SHOULD IT RECEIVE A PACKET CONTAINING ERRORS WHICH CANNOT BE CORRECTED, AND WHEREIN SHOULD THE ERROR RATE IN RECEIVED PACKETS BE MORE THAN A PREDETERMINED AMOUNT OVER A PREDETERMINED INTERVAL OF DATATRANSMISSION, THE SYSTEM IS ARRANGED AUTOMATICALLY TO REDUCE THE RATE OF DATA TRANSMISSION WITHIN EACH PACKET AND/OR CHANGE THE CHANNEL FREQUENCY.(FIG 1)