99740 results about "Communications system" patented technology

A method is described of calculating and verifying the integrity of data in a data communication system. The system comprises a base station and one or more remote stations, such as in an RFID system. The method includes transmitting a select instruction from the base station to the one or more remote stations, the select instruction containing a data field which matches a portion of an identity or other data field in one or more of the remote stations; transmitting from a selected remote station or stations a truncated reply containing identity data or other data of the remote station but omitting the portion transmitted by the base station; calculating in the base station a check sum or CRC from the data field originally sent and the truncated reply data received and comparing the calculated check sum or CRC with the check sum or CRC sent by the remote station.

A method of message communication via a messaging system between one or more originating communication devices assigned to a sender and one or more destination communication devices assigned to a receiver, a messaging system, a service center and a client thereof. The method comprising: before delivery to the receiver, obtaining by a messaging system a message having initial characteristics comprising message format and message layout; adapting at least one of said initial characteristics of the message in accordance with at least one criterion selected from a group comprising: —criterion related to message communication capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; —criterion related to message displaying capabilities of the destination communication device with regard to message communication capabilities of the originating communication device; —criterion related to communication media between originating and destination device; and facilitating delivery of the adapted message to the receiver.

The present invention provides a system for operating a power line communications system that employs surface wave communications and conducted communications. The system is comprised of a plurality of network elements, which may take the form of repeaters, communication interface devices, backhaul devices, medium voltage transducers, distribution points, aggregation points, and others. In one embodiment, surface waves are communicated over the medium voltage power lines and the conducted communications are communicated via the low voltage power lines to and from customer premises.

There is disclosed a radio communication system in which a constitution of a base station and further a control station can be simplified. A radio communication system according to the present invention converts a received signal received by a plurality of antenna elements in a base station to a signal of different frequency band, and then conflates the converted signal in order to generate sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then the optical signal is transmitted to a control station via an optical fiber. Or the control station performs weighting to phase of the transmitted signal transmitted from a plurality of antennas of a base station, and then performs frequency conversion to different frequency band, and then conflates the converted signal in order to generate the sub-carrier wave multiplex signal. The signal is converted to an optical signal, and then an optical signal is transmitted to the base station side via the optical fiber. The control station and the base station divides the received sub-carrier wave multiplex signal by each frequency band, and then the frequency of the divided signals are converted to the same frequency band in order to generate the transmitted / received signal of each antenna element. By such a constitution, it is possible to reduce constituent of the optical transmission components to the minimum and to simplify the constitution of the base station. Furthermore, it is possible to maintain the relative phase difference and the relative intensity of the transmitted / received signal of each antenna element. Because of this, it is possible to estimate an arrival direction of the received signal and to control radiation beam pattern of the transmitted signal.