In a network that roughly comprises a temporary master station and a plurality of slave stations and is an adhoc network, which can be immediately constructed in situ, and is a temporary master station interposition-type network in which a temporary master station is present, the temporary master station receives and judges an interference detection packet sent from the slave station. By virtue of this construction, an asynchronous interference avoiding method and an asynchronous interference avoiding system can be realized which can reliably avoid interference.

A radio communication system including a plurality of base stations which communicate with a plurality of radio terminals respectively is provided with a capability of avoiding occurrence of radio interference of control channel signals among a plurality of base stations even when a plurality of the base stations are located in the close vicinity of each other. The base station of the radio communication system is provided with a device for receiving, when the power is turned on, a control channel signal which is being transmitted at a certain interval by each of the other base stations in the system, a device for frame synchronizing each of TDMA frames of the control channel signal which is received, a device for extracting base station identification information of each of the other base stations from the TDMA frames which are frame synchronized, and a device for storing in a memory each of the base station identification information which is extracted. The base station further includes a device for determining a cycle of transmitting a superframe signal in accordance with the number of the other base stations using the control channel in the system, which is determined based upon the base station identification information stored in the memory.

A method and system for controlling media access in which a paging message is transmitted from a base station to a wireless station when a data packet is received for downlink transmission to the wireless station. The base station is one of a plurality of base stations and the wireless station is associated with the base station. In response to the paging message, a level of each of a plurality of pilot frequency signals is detected at the wireless station. Each pilot frequency corresponds to a downlink traffic channel and is transmitted by base stations to which the downlink traffic channel is assigned. The wireless station generates a list of preferred traffic channels based on a priority order of traffic channels and on detected levels of the pilot frequency signals, and transmits the list to the associated base station. A downlink traffic channel is assigned for downlink transmitting the received data packet to the wireless station based on the list of preferred traffic channels and updates a channel priority order list at the base station.

In a method for controlling call access of a terminal in a mobile communication system based on cellular communication system, call access of mobile terminals can efficiently be controlled depending on the state of individual resources of Walsh code classes assigned to each mobile terminal from the base station and the state of a reverse link in a communication system which supports multi-transmission rate depending on service options of the mobile terminals. The method for controlling call access of a terminal in a mobile communication system includes the steps of permitting a base station to periodically broadcast call access control information including traffic information of a reverse link and information of at least one or more code classes in which Walsh codes assigned to a mobile station from the base station are classified depending on transmission rate, to a plurality of mobile terminals in its cell or sector, and permitting the mobile terminal to periodically receive the call access control information and requesting call access of the base station depending on the call access control information.

The object of the invention is to allow two systems residing in the same area and same frequency band to be coexistent compatibly with each other while reducing the mutual interference. A radio network controller 20 for controlling the broadcast timing when various kinds of broadcast information is broadcast with respect to each of two systems, which reside in the same frequency band of the same area and have common specification for physical layer in a state where all or a part of upper layer protocols have no compatibility, broadcasts various kinds of broadcast information about system 1 at a predetermined timing. With respect to various kinds of broadcast information about system 2, broadcast timing information, which is scheduled to be staggered from the broadcast timing of the system 1, is notified using a part of region of the broadcast information, and the broadcast information of the system 2 is broadcast at the notified broadcast timing.