Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Yoshihiro Takehisa

Shinji Fukuda

Takatsugu Ito

Toshiyuki Sugitani

Tetsuya Ashizuka

Shigeki Yagi

Katsumi Nakagawa

Koji Nitta

A radio communication system of a frequency hopping system, which carries out time division multiplex by TDMA and carries out communications while changing over two or more frequencies with respect to a radio link, wherein radio resources are efficiently utilized by establishing a plurality of radio links. A first communication apparatus periodically transmits control data by a frame cycle and a second communication apparatus which is a communication partner thereof receives the above-described control information during standby and secures synchronization in timing of frames and slots and timing of frequency hopping. Communication signals between both communication apparatuses and control information are overlapped in a slot to establish radio links. Once radio links are established in a plurality of slots other than a slot for transmitting control information, control is performed such that the control information is overlapped in the slots in which a radio link is established.

Radio communication system and communication method

The invention provides a frequency hopping method for switching a hopping carrier frequency in a predetermined hopping pattern based on a hopping carrier table, in which there is provided intermittent receiving means for starting carrier frequency designating means every constant cycle to give a command for receiving the control channels of opposed radio base stations. In the case in which a hopping order in a hopping carrier table is skipped by n to carry out switching every intermittent receiving cycle in an intermittent receiving operation, an intermittent receiving cycle is set in such a manner that the n and a total number m of hopping carrier frequencies in the hopping carrier table have a prime relationship with each other. Moreover, the electric field strength of a carrier frequency in a spare carrier list is measured by the intermittent receiving operation and an interference counter of a spare carrier is increased or decreased corresponding to a frequency at which the electric field strength exceeds a predetermined threshold, and a carrier frequency deleted from a hopping pattern is set to have the worst value as the initialized value of the interference counter. A standby is maintained in a state of a non-exchange until the frequency at which an electric field strength measured for the frequency exceeds a threshold is sufficiently reduced, and the same frequency is recycled as an exchangeable carrier frequency after sufficiently confirming that a communication can be carried out.

Radio communication apparatus and interference avoiding method

In a time division multiplex access (TDMA-TDD) type wireless communication system in which a communication operation is carried out between a first communication apparatus (mother appliance) and a second communication apparatus (child appliance), and since a slot diversity mode is selected while considering power consumption on the side of the second communication apparatus, the wireless communication system performs such a wireless communication having a higher wireless quality. Based upon a power supply remaining energy capacity on the side of the second communication apparatus, and an electromagnetic wave environment when a wireless signal is received, a slot diversity mode is selected. For example, it is so assumed that 1 frame corresponds to 8 slots, a wireless signal is transmitted from the first communication apparatus to the second communication apparatus by employing two, or more slots, whereas a wireless signal is transmitted from the second communication apparatus to the first communication by employing one slot within the remaining 2 to 6 (8-2) pieces of the slots. As a result, since a total number of the wireless transmission slots used in the second communication apparatus is reduced, transmission electric power can be lowered which may occupy a large ratio within the entire power consumption.

Wireless communication system and communication method

For the purpose of being capable of performing direct inter-handset communications while maintaining inter-handset communications via a base unit, smoothly making a transition from inter-handset communications via a base unit to direct inter-handset communications, and switching to inter-handset communications via a base unit without releasing the communications even in case direct inter-handset communications cannot be established, a local handset includes a direct inter-handset communications controller and a direct inter-handset communications transition controller for making control to establish direct inter-handset communications while maintaining communications with a base unit as well as transmitting control channels for direct inter-handset communications in vacant slots in the receiving time zones for communications with the base unit, while a distant handset includes a direct inter-handset communications controller and a direct inter-handset communications transition controller for scanning control channels for direct inter-handset communications in the time zones other than the slots occupied by communications with the base unit

Digital radio communications apparatus

A button telephone system includes a parent telephone set and a child telephone set which are capable of radio communication. In a state in which data communication with a host private branch exchange is made, the parent telephone set is constructed so that it enters a mode in which a public telephone line condition signal sent from the host private branch exchange is converted into a signal adapted for the child telephone set and the converted signal is sent as a line vacant condition display signal to the child telephone set by radio waves. Even in the case where the parent telephone set is connected to an extension telephone line of the host private branch exchange, it is possible to transmit information of the public telephone line condition of the host private branch exchange intact to the child telephone set so that it is displayed in the child telephone set. Accordingly, a user can make signal transmission to a public telephone line after the public telephone line condition of the host private branch exchange is confirmed in the child telephone set.

Growing community of inventors

Fukuoka, Japan

Yoshihiro Takehisa