Abstract: The present invention overcomes the prior art limitations by dividing a coverage area into very small regions or cells. The inventive system can be built as an adjunct to a wired telecommunication system such as a PBX. Advantageously, because of the relatively small size of each cell, transceivers in the inventive system can use very low transmission power, compared with a pico-cellular communications system, to communicate with a fixed transceiver. In addition, because of the relatively short distance between the mobile handset and the fixed transceiver, the communication paths between any two transceivers are reduced and, therefore, the multipath distortion which can affect the received signals is substantially reduced.A concomitant problem normally associated with relatively small cells is the need for a switching system which can accommodate the large amount of switching or handovers required to accommodate the various mobile units as they move from one cell to another.

Abstract: An adaptive circuit is used in the process of recovering data from a signal received from a communications channel. This circuit scripts or varies its transfer function in response to a first error signal derived from the received signal. This adaptation results in the device's transfer function settling to a converged state. An auxiliary information recovery circuit receives the recovered data and derives auxiliary information therefrom. To avoid the problem of false state convergence, the auxiliary information circuit provides a second error signal which causes the adaptive device to reinitiate the adaptation process. In the disclosed embodiment, the adaptive circuit is an equalizer and the auxiliary information recovery circuit is one which recovers framing information or is an error correction circuit. The inability of the auxiliary information circuit to function properly is used as an indication of false convergence of the adaptive circuit.

Abstract: A signal compression-selection arrangement (19) dynamically trades off signal storage capacity against signal quality, by sacrificing capacity in favor of signal quality whenever capacity is plentiful and sacrificing quality in favor of capacity whenever capacity is scarce. In a messaging system (FIG. 1), the arrangement monitors the amount of storage (14, 15) that is presently free and available for storing new messages, either on a system-wide or per-mailbox basis, and automatically selects a higher compression rate (13) than a presently-applied compression rate (13) to be applied to newly-received messages as the amount of free storage falls below each predetermined threshold. Storage capacity may be freed up by re-compressing (FIG. 3) at the new, higher, compression rate those stored messages that were previously compressed at a lower compression rate.

Abstract: In a simultaneous voice and data communication system, a stream of signal points is partitioned into a plurality of symbol blocks, each symbol block including a data segment and a control segment. The data segment carries information from a user, i.e., user data, while the control segment provides control information. A voice signal is then added to at least a portion, or all, of the signal points of each symbol block to provide for simultaneous voice and data transmission to an opposite endpoint. The control information may represent information from a secondary data source, and/or may include information about the characteristics of the succeeding block, e.g., the user data rate, and information pertaining to characteristics of the communications channel.