A STUDY ON CHANNEL USAGE IN A CELLULAR-CENTER-DOT-AD-HOC UNITED COMMUNICATION-SYSTEM FOR OPERATIONAL ROBOTS

A communication system which attains an efficient amalgamation of base station (BS) type cellular communication and non-BS type direct commu nication for mobile terminals (MTs), ''cellular-ad-hoc united communic ation system,'' is proposed. In this system, whether a cellular system or an ad-hoc communication system is chosen by distance and whether t he condition is good or not between communicating MTs. In other words, when two terminals are relatively near each other and are in sufficie nt conditions to communicate directly, they select the ad-hoc communic ation, while for other cases they use the cellular system. The propose d system was confirmed to have effective channel usage and low battery consumption from the simulation results. It can be also said that thi s system is suited especially for MTs which tend to communicate with c loser partners such as operational mobile robots and autonomous carrie r vehicles.