The transmission quality of a first data stream, in particular a real time data stream, which competes with at least one further data stream for a restricted transmission capacity at a network node in a data packet oriented communication network, is improved by increasing the data rate of the first data stream by adding redundant data at the transmitter end. During an overload situation, the increase in the data rate of the first data stream in comparison to that of the at least one further data stream overrides the latter to the extent that a greater proportion of the jointly available transmission capacity at the network node is now taken up by the first data stream.

A radio communication system adapting TDD/FH, for reducing interference of jammer, preventing third party's hearing, and enhancing frequency usage efficiency. The radio communication system adapting time division duplexing/frequency hopping, having: a data source for providing transmission data or receiving input of reception data; a hop frequency generator for generating frequency changed as frequencies preset at every given time; a frequency modulator for modulating frequency according to the transmission frequency corresponding to the hop frequency with provision of the transmission data; a power amplifier for power-amplifying output of the frequency modulator; an antenna for receiving input of a signal outputted from the power amplifier at a regular time period and radiating the inputted signal or receiving reception data; a bandpass filter for bandpass-filtering reception data received from the antenna depending upon the hop frequency; a switch for connecting the antenna with the power amplifier upon transmission and connecting the antenna with the bandpass filter upon reception; a reception frequency mixer for receiving input of the bandpass-filtered reception signal and mixing the received signal with reception frequency corresponding to the hop frequency; an intermediate frequency mixer for receiving output of the reception frequency mixer and mixing the received signal with an intermediate frequency; and a frequency demodulator for receiving output of the intermediate frequency mixer, demodulating frequency, and again inputting the demodulated frequency to the data source.

A hopping control device selects one hopping pattern out of hopping patterns P1 to PN, reads out a hopping frequency sequence arranged in the selected hopping pattern from a frequency hopping pattern memory, and sends the hopping frequency sequence to frequency synthesizers as a frequency designation signal by wire at a predetermined period. The frequency synthesizers generate local oscillation signals of a frequency specified by the frequency designation signal, respectively, and output the local oscillator signals to mixers, respectively, to thereby perform communication by a frequency hopping system between a first housing unit and a second housing unit.

A wireless communication device for performing bi-directional communication using a frequency hopping method, in which the communication time at any one frequency can be varied. The user uses the dial to adjust the length of time during which a single frequency is used. Accordingly, if the volume of data is large, as in image data, the communication time can be increased. If the volume of data is small, as in voice data, the communication time can be decreased. If privacy is desirable, the communication time is decreased, whereas increasing the communication time will increase the transfer rate. Such settings can be made manually by the user to suit the user's needs, or can be made automatically based on the type of data being transferred.

A method of dynamic channel allocation in a frequency hopping communications system is disclosed providing improved efficiency and reliability. During the course of communications between a plurality of transceivers over a frequency hopping wireless communications link, a transceiver begins evaluating the performance of each channel in the hop sequence, starting at a fixed point in the sequence. The transceiver proceeds sequentially through the hop sequence, until a channel fails to satisfy a predetermined quality criterion. A channel which fails to satisfy the quality criterion is considered bad, and substituted with a replacement channel from a set of available channels via an unacknowledged channel replacement command. The channel evaluation process is subsequently reinitiated beginning anew at the fixed point in the hop sequence, thus operating to maintain a set of consecutive good channels.