Abstract: A method and system for managing a plurality of defects that may cause an error during a write operation in a write-once data storage disk is provided. A host system sends a write command to a disk drive that contains the storage disk. The process detects any errors that may occur during the write operation. When an error is detected, a “skip list” containing the addresses of physical sectors on the disk that are to be skipped during a read operation is updated, the write operation is suspended, and the process attempts to rewrite the data in another sector. If the rewrite is performed successfully, the write operation continues. Otherwise, the write operation is terminated and the host device is notified. While the disk drive is operative, the skip list is preferably maintained in a buffer memory, but periodically the entries in the skip list are copied to the disk for permanent storage. Before a read operation begins, the skip list is copied from the disk to the memory.

Abstract: This disclosure relates to varying load and modulation applied to each of multiple frequency subchannels based on anticipated attenuation experienced by those subchannels. Communicating data includes identifying a static component of a transmission medium for wideband communications having at least two subchannels, determining a function of noise or attenuation versus frequency for the static component, selecting wideband modulation schemes for the subchannels based on the function determined, and communicating a data signal over the subchannels. Independent demodulation functions may be applied to at least two of the subchannels.

Abstract: A file system for accessing information on digital storage media is provided by a storage device controller embedded within the storage device. The storage device controller includes an interface component to receive a packet having a file system command. A command decode component in the storage device controller decodes the file system command, and an interface response structure component creates a strategy for performing the file system command. The storage device controller generates an identifier for a file system object and accesses the file system object using the file system object's identifier. A host system coupled to the storage device receives a storage device access request from an application program and generates a command to perform on the file system object based on the storage device access request. The host system uses the identifier to indicate the file system object to be accessed.

Abstract: A data storage disk includes a writeable area that allows a user to write data, wherein the data files are written from the outside diameter towards the inside diameter of the writeable area, while file system information is written from the inside diameter towards the outside diameter of the writeable area. This optimizes the use of the writeable area, whether a large number of small data files or a small number of large data files are being stored. To further optimize the use of the writeable area, information may be stored in two or more different error correction code (ECC) block sizes. Thus, information, such as the file system attributes and linking sectors, which contains few bytes may be stored in the smaller ECC block size, while the data may be stored in the larger ECC block size. The data storage disk, may also include a mastered content area.

Abstract: A media access control (MAC) controller is disclosed for a network providing communication for network stations located at a plurality of customer premises and sharing a communication medium, each of the premises having a plurality of network stations. The MAC controller includes a virtual local area network (vLAN) controller, providing access to the communication medium for and communication among the stations located at a single customer's premises, to define a vLAN between them. A group local area network (gLAN) controller provides access to the communication medium for and communication among interfering vLANs, two vLANs being considered to be interfering when one can sense communications over the medium from a station in the other. A MAC controller is provided in at least one station in a vLAN.

Abstract: A method and system for managing a plurality of defects that may cause an error during a write operation in a write-once data storage disk is provided. A host system sends a write command to a disk drive that contains the storage disk. The process detects any errors that may occur during the write operation. When an error is detected, a “skip list” containing the addresses of physical sectors on the disk that are to be skipped during a read operation is updated, the write operation is suspended, and the process attempts to rewrite the data in another sector. If the rewrite is performed successfully, the write operation continues. Otherwise, the write operation is terminated and the host device is notified. While the disk drive is operative, the skip list is preferably maintained in a buffer memory, but periodically the entries in the skip list are copied to the disk for permanent storage. Before a read operation begins, the skip list is copied from the disk to the memory.

Abstract: An optical disc drive waits to receive a command to perform a function on optical media in the disc drive. The optical media includes a pitted premastered area that cannot be overwritten and a grooved user-writeable area that can be overwritten. Once a command is received, one portion of the disc drive processes the command while another portion of the disc drive monitors the processing of the command and waits until the command is processed. If an error condition is detected while processing the command, the disc drive generates an event request such as a notify event request, a focus event request, a spin event request, and a tracking event request. When an event issues, the disc drive interrupts processing of the command and attempts to recover from the error condition. The state of the disc drive when the requested event was received is saved before attempting to recover from the error condition.

Abstract: A system and method for controlling operation of a disc drive for optical media. The optical media includes a pitted premastered area that cannot be overwritten and a grooved user-writeable area that can be overwritten. The disc drive determines the position of an actuator arm in relation to the grooved and pitted areas, and enters a physical sector address (PSA) idle state, where no attempts to read physical address sectors (PSAs) are made when tracking or focus are not active. The drive transitions from the PSA idle state to a PSA enable state when tracking becomes active, and to a PSA locked state where PSAs can be read when both focus and tracking are active. The drive also re-attempts to acquire a PSA when the PSA cannot be read within a predetermined time period. The re-attempt includes toggling between control system settings appropriate for pits and settings appropriate for grooves.

Abstract: A novel apparatus and method are provided for data communication over noisy media. The apparatus includes one or both of a transmitter circuit located at a transmitting location and a receiver circuit located at a receiving location. The data is encoded to provide error correction capabilities. The encoded signal is further modified by performing one or more linear mathematical operations in order to further randomize the data signal. The transmitter circuit thus generates a wideband spread spectrum signal based on the data which is to be transmitted, which spreads the signal and improves its immunity to noise. The coding used to spread the data signal may or may not be a function of the data itself. The present invention provides enhanced noise immunity without any resulting degradation in the operation and efficiency of the error correction coding.

Abstract: A novel apparatus and method are provided for data communication over noisy media. The apparatus includes one or both of a transmitter circuit located at a transmitting location and a receiver circuit located at a receiving location. The data is encoded to provide error correction capabilities. The encoded signal is further modified by performing one or more linear mathematical operations in order to further randomize the data signal. The transmitter circuit thus generates a wideband spread spectrum signal based on the data which is to be transmitted, which spreads the signal and improves its immunity to noise. The coding used to spread the data signal may or may not be a function of the data itself. The present invention provides enhanced noise immunity without any resulting degradation in the operation and efficiency of the error correction coding.

Abstract: The present invention is for a system which uses a non-telephone wiring network, such as the existing electrical low voltage wiring of the power line distribution network to provide telephone line service to individual users. The low voltage wiring referred to herein is that used to distribute power to individual businesses and residences, e.g., 120 V single phase residential service. The telephone line service is "on-demand" in the sense that any user can interface a telephone, or other communications device, to the electrical wiring and thereby instantly obtain telephone line service. The system of the present invention may be used to provide primary telephone service to those users who do not wish to pay the expense for dedicated line service. Alternatively, the system of the present invention may be used to provide secondary telephone service, i.e., second, third, . . . line, telephone service for those users who do not wish to pay the expense for dedicated secondary line service.

Abstract: A novel apparatus and method are provided for data communication over noisy media. The apparatus includes one or both of a transmitter circuit located at a transmitting location and a receiver circuit located at a receiving location. The data is encoded to provide error correction capabilities. The encoded signal is further modified by performing one or more linear mathematical operations in order to further randomize the data signal. The transmitter circuit thus generates a wideband spread spectrum signal based on the data which is to be transmitted, which spreads the signal and improves its immunity to noise. The coding used to spread the data signal may or may not be a function of the data itself. The present invention provides enhanced noise immunity without any resulting degradation in the operation and efficiency of the error correction coding.

Abstract: A power line communication system specially designed for use in local area network (LAN) configurations has receiver and transmitter sections for fast, highly reliable data communication. The receiver includes controlled adaptive second order filters for ensuring data reception in virtually any signal environment having noise and distortion characteristics, especially alternating current (AC) power lines. A wideband phase shift-keyed (PSK) carrier is impressed on the transmission medium, the carrier having power spread approximately uniformly across a useful frequency bandwidth. A transmitter section is arranged for adaptive feedback control of the transmitted signal power, so as to prevent possible damage to the transmitter when the transmission medium impedance is low. A logic control circuit provides a correlation count of a received signal in comparison with a known reference signal in order to effectively achieve phase synchronization between the receiver and transmitter.