A communication network advantageously uses existing broadcast channels to instruct remote receivers and eventually use automatic dial-up capability for forming a telephone communication link with a central processing facility. The network is capable of providing many services from remote reading of meters to electronic mail and electronic billing. The network is preferably shared by a number of large users communicating with a host of subscribers.

A high-speed fiber optic star configuration network uses a processor at the network hub to monitor and control network activity. The hub and the individual nodes of the network cooperate to calibrate node transmitter power levels and node receiver sensitivities. A token passing protocol is used to allocate network access. The token passing is monitored at the hub to detect lost tokens or a babbling bus. The hub processor has the capability to initiate tokens or restore lost tokens and to shut of...

A communication apparatus used in a digital cordless telephone system, such as a personal headphone system (PHS) having a local base station and a local mode subscriber, in which, if the local mode subscriber is set for use in the local mode, the local mode subscriber can respond to signals of the public mode. If the local base station receives incoming call signals of the public mode from a public base station, the received call signals are transferred from the local base station to the local m...

Cellular mobile telephone stations which are intended for installation and use in public transportation facilities, e.g., taxicabs, limousines, rental cars, etc. are equipped to support credit card billing of transient customers for use of the station services. The cellular pay stations, from the viewpoint of serving cellular carrier facilities, are indistinguishable from standard cellular mobile stations. The activities of the credit card stations are supported by an administrative processor wh...

A communication device wherein leader pulses which continue for a predetermined time period are transmitted prior to the transmission of data from its transmitter; its receiver is rendered intermittently operative at a cycle shorter than half the continuation time of said leader pulses by means of a cycle operation controlling means to thereby become operative for a short time at a duty lower than 1/10; while the receiver is operating, it is detected by a detector means whether or not the leader...

A communication or educational aid comprising a housing having a generally flat surface, and a pointer is mounted for rotation on the surface. A pair of spaced guides are located on the surface and a panel or overlay containing a plurality of symbols, such as letters, words, pictures, or the like, is mounted in the guides and is provided with a slot which registers with the shaft of the pointer. The pointer is rotated by depressing a push button operating through an electrical circuit to thereby...

A communication interface for effecting communication by serial bit packets on unidirectional non-shared lines comprises a packet generator 70 arranged to output a byte of data in a data packet of a first format or an acknowledgement packet of a second format and a packet decoder 71 is arranged to decode incoming packets.

A portable information marker having a tetrahedron stand joined to a base supported on a surface. The stand has a top wall releasably accommodating an information unit. The information unit and top wall have interlocking slot and ear structures allowing the information unit to be removed from the top wall and replaced with an alternate information unit. The alternate information unit can be a flashing light unit.

A frequency hopping communication system whose transmitters and receivers after synchronization hop over a frequency series of a first type. To synchronize the transmitters and receivers, sync data from a transmitter are transmitted and received in portions spread over a frequency series of a second type in order to protect the transmission of sync data against jamming and eavesdropping.

Method and apparatus is disclosed which disables which disables a repeater connected to a packet-based network so that improper symbols are not propagated. A communications management unit employing the invention would, upon reception of an improper symbol, cause transmission to halt. The invention implements a three-state machine. Reception of any improper symbol, or symbol with a parity error, causes entry into a forced-halt state. Reception of an IDLE symbol causes transition to a forced-idle...