Multi channel access control method for service on a plurality of terminals and network system using the same

PURPOSE: A multi-channel connection controlling method and a network system applying the same are provided to supply a message by broadcast in a transmission channel and to transfer the message by unicast in a reception channel. CONSTITUTION: A wrist band receives a broadcast message from a coordinator through a BCH(Broadcast CHannel)(S320). If the message is transmitted to the coordinator, the wrist band switches a connection channel to an SCH(Service CHannel). In case the SCH is in an idle state, the wrist band transmits the message to the coordinator through the SCH(S335,S340). In case the SCH is in a busy state, the wrist band waits for(S345). [Reference numerals] (S305) Channel scan/search; (S310) Message confirmation; (S315) Channel connection; (S320) Broadcasting message receipt; (S325) Message to be transmitted generation?; (S330) Channel conversion(BCH->SCH); (S340) Message transmission; (S345) Standby; (S355) ACK receipt?