Abstract: A telecommunications sytem comprises a plurality of distributed base stations each operatively coupled to a public switched telecommunications network and being adapted to cooperate with one or more of a plurality of portable cordless telephone units by way of a plurality of cordless digital communication channels operating on a time division duplex basis. The base unit is arranged upon detection of an incoming public switched network call, to poll all the portable cordless telephone units by transmitting on a repetitious basis the identity of the portable units to be connected to the incoming call on a selected channel and the base unit is arranged to intersperse each poll operation with a signalling message.

Abstract: A digital data interface for high speed asynchronous data transfer is described. The design is nominally intended for integration onto the component chips in communications systems. The system is described with respect to its realization in CMOS IC technology. The techniques involved, however, may easily be applied to other technologies. The interface employs Manchester Bi-Phase Mark encoding of the clock and data to allow extraction of the clock and data signals at the receiver. Furthermore, use of this Manchester code allows code violations to be easily employed as frame markers for synchronization means. The essence of the clock extraction and data detection circuit is the use of calibrated delay line elements to suppress data transitions within the coded input signal, thus allowing the clock transitions to be detected from which the clock is then generated.

Abstract: The coin handling system prevents coin to coin contact taking place in coin operated equipment. This is achieved by an arrangement whereby the presence of a coin activates a first lever which moves a second lever in the coin path behind the coin so that a subsequent coin abuts the second lever. A series of such levers are employed in the coin store of coin operated equipment, the actual number depending upon the number of coins to be stored. When the first coin is cleared from the store by a suitable gate arrangement, all coins move along the store by one position, the separation being maintained by the interaction of the levers and coins. The advantages of the system are that a wider range of coins from one coin set can be accommodated in a single store than is presently possible. The coin insertion sequence is maintained for the purposes of microprocessor control since a single store is used. Since coins cannot overtake each other the risk of coins jams is lessened.

Abstract: The invention provides a tip party identification facility in association with a subscriber line interface circuit. The tip party identification facility takes advantage of a shutdown feature and the output of a common mode error amplifier of the subscriber line interface circuit. The use of this facility enables the central office to determine whether the tip party or ring party is off-hook for billing purposes.