Abstract: The compression method utilizes a combination of both lossy and lossless compression to achieve significant compression while retaining very high subjective quality of the reconstructed or decompressed signal. Methods and apparatus for compression and decompression of digital audio data are provided. In one preferred embodiment, the compression method or apparatus employs an approximation of a psychoacoustic model for wavelet packet decomposition and has a bit rate control feedback loop particularly well suited to matching the output bit rate of the data compressor to the bandwidth capacity of a communication channel.

Abstract: An electrical connector particularly adapted for use in a PCMCIA standard connector designed for increased performance, ease of manufacturing, and allowing the connector casing to contain a printed circuit board having larger components is presented. A grounding shield with a hallowed-out area is implemented in the connector casing to create more room for a PC board given the same amount of vertical clearance allowing componentry to be larger than would otherwise be possible. Further, the grounding shield has a soldering cup to allow better adhesion of the solder to the plated grounding shield and to allow the connector to be more easily manufactured. The buttons used to disengage the connector from its receptacle are extended outward from the connection to provide easier accessibility in limited space circumstances. Additionally, the casing and buttons have opposing angles in order to provide more convenient and sure grasping by the user.

Abstract: A novel line-current protection circuit and method that is useable with a PCMCIA modem card is disclosed. The protection circuit is adapted to detect when an excessive voltage is present across the tip and the ring leads of a telephone subscriber loop by sensing the amount of line-current being supplied to line interface circuitry disposed on the PCMCIA modem card. The protection circuit includes a current sensing circuit portion that is placed in series with the tip lead and which detects when the line current exceeds a predetermined maximum amount. In the event the line current exceeds the maximum, the current sensing circuit asserts an excessive line current signal. A control and delay circuit causes the relay circuit to open the electrical connection between the modem and the telephone line only when the line current exceeds a predetermined maximum amount for a minimum amount of time.

Abstract: An electrical power management system for supplying power to a computer peripheral having a relatively high intermittent power demand, such as a packet-switched data radio. A first self-contained rechargeable power supply, outputting power appropriate for the electrical appliance, stores electrical energy and supplies power to the appliance. A second self-contained rechargeable power supply stores electrical energy and supplies electrical power to intermittently recharge the first power supply. The first and the second power supplies can be such self-contained units as single or multicell batteries or capacitors. Preferably, the first power supply is a battery or a capacitor and the second power source is an internal power supply of a portable personal computer.

Abstract: A reconfigurable communication interface system is provided comprising a reconfigurable communication interface device and a communication adapter cable. The reconfigurable communication interface device contains means to identify a valid communication adapter cable. After an attached communication adapter cable is recognized as valid, operational values are downloaded from outside the communication interface device and the communication interface device software is reconfigured. Operational values may be loaded from the communication adapter cable or from the host computer. Adapter cables for a wide variety of applications such as various telephone networks, various cellular telephones, Ethernet networks, PBX type networks, ISDN type networks, optical networks, or other LAN and WAN type networks are provided.

Abstract: An electrical power management system for supplying power to a computer peripheral having a relatively high intermittent power demand, such as a packet-switched data radio. A first self-contained rechargeable power supply, outputting power appropriate for the electrical appliance, stores electrical energy and supplies power to the appliance. A second self-contained rechargeable power supply stores electrical energy and supplies electrical power to intermittently recharge the first power supply. The first and the second power supplies can be such self-contained units as single or multicell batteries or capacitors. Preferably, the first power supply is a battery or a capacitor and the second power source is an internal power supply of a portable personal computer.