In the communication system performing transmission with generating the vacant period in the slotted mode during data transmission in order to perform various process, such as different frequency carrier quality measurement or so forth, the control signal for maintaining a communication quality is inserted...http://www.google.de/patents/US7944950?utm_source=gb-gplus-sharePatent US7944950 - Mobile communication system, communication control method, and base station and mobile station to be employed in the same
