Abstract: A method of transmitting data from a user terminal to a base station using a hybrid automatic repeat request (HARQ) scheme with a plurality of redundancy versions of said data, each of the redundancy versions (RV) indicating a transmission start position of a data block in a circular buffer is disclosed. For each retransmission, the redundancy version to be used by considering the previously used redundancy version and a predetermined sequence is determined. Within one sequence, at least two redundancy versions following each other have non consecutive start positions.

Abstract: Within a communication system in which an ARQ control is exercised, in a transmission-side communication apparatus 11, a transmission scheduling unit 113 determines a transmission amount to be transmitted to a reception-side communication apparatus 21; an erasure correction encoding unit 112 performs an erasure correction encoding process on an information packet group that is made up of a plurality of packets to be transmitted so as to generate one or more erasure correction coded packets that fit the transmission amount instructed by the transmission scheduling unit 113 and specifies the one or more erasure correction coded packets as a unit of delivery confirmation; and a modulating unit 115 transmits a transmission data signal that has been generated by performing a predetermined modulation process on each of the erasure correction coded packets.

Abstract: There is disclosed a source messaging system having a queue for receiving messages. The source messaging system has means for determining whether a message should be permitted to become INDOUBT. This is done by retrieving a value denoting the maximum number of messages that may be permitted to become INDOUBT at any one time; determining whether the message falls within the range denoted by the value; and responsive to determining that the message falls within the range, permitting the message to become INDOUBT.

Abstract: Systems and methods for managing a redundant management module are provided. In this regard, a representative system, among others, includes first and second management modules that are configured to manage a computing device; and a programmable logic device that is configured to: instruct the first management module to manage the computing device responsive to detecting that the first management module is ready to manage the computing device, and instruct the second management module to manage the computing device responsive to detecting that the first management module failed to manage the computing device.

Abstract: A method for delivering/receiving content in a mobile communication system. A terminal sends a Content Delivery Repair Request message requiring repair of the content to a server, when reception of the content provided from the server is not normally carried out; and receives a Content Delivery Repair Response message from the server in response to the Content Delivery Repair Request message. The server receives a Content Delivery Repair Request message from the terminal, when reception of the content is not normally carried out at the terminal, and sends a Content Delivery Repair Response message in response to the Content Delivery Repair Request message.

Abstract: Methods and apparatus for processing error control messages, such as RLC ARQ control messages, are disclosed. An exemplary method comprises signaling a medium access controller (MAC) that link resources are needed for transmitting data, receiving an indication from the MAC that link resources for transmitting the data are scheduled, and generating an error control message after receiving said indication, based on a current error control status. The error control message is then forwarded to the MAC for transmission. Because the generation of an error control message is delayed until resources for its transmission are scheduled, the queuing of stale control messages is avoided.

Abstract: A data transmitter transmitting a data packet containing identifier information including a kind of data, a sequence of data, and/or a packet generating sequence. A receiver extracting a packet number and the identifier information for an error-receipt occurring data packet based upon the identifier information recorded in a header of the packet, generating retransmission control information, such as retransmission times and priority, based on the extracted packet number and the identifier information and transmitting the retransmission control information to the transmitter of the packet. The retransmitting the error-occurring data packet according to the received retransmission control information. The number of retransmissions and the retransmission priority can be varied according to characteristics of the transmitted data, so that retransmissions is suitable for the characteristics of the data and to more stably receive the data that is more influential to the restoration of the data.

Abstract: A storage control device includes a first rebuilding unit rebuilding information stored in one of a plurality of storages that fails by using information stored in the plurality of storages excluding said failed storage and storing rebuilt information in a spare storage replaced with the failed storage, a second rebuilding unit rebuilding information stored in two of said plurality of storages that fail by using information stored in said plurality of storages excluding the two failed storages and storing rebuilt information in two spare storages replaced with the two failed storages, and a rebuilding control unit for controlling said first rebuilding unit and second rebuilding unit where one of said spare storages fails during rebuilding the data stored in said two failed storages to replace the failed spare storage with other spare storage whereby said second rebuilding unit continues rebuilding the data.

Abstract: An access control apparatus includes a memory and a command executor executing an access process on a command with the command completion time limit. An address of an inaccessible recording area is stored in the memory. Data attempted to be written on the inaccessible recording area is obtained. The data is stored in association with the address in the memory. An automated alternate processor executes the automated alternate process of the inaccessible recording area in a predefined period of time after the process executed by the command executor is completed. A memory updater deletes the address of the inaccessible recording area whose automated alternate process has succeeded and the data attempted to be written in the recording area at the address.

Abstract: A method enables efficient and coherent sample data storage in a system containing data transmitting and receiving devices. The algorithm is implemented by storing reverse-delta encoded data at a receiver side in a chronologically correct order by a data list and a recovery table, independently of the transmission device. The sender device compares a previously attached timestamp corresponding to each sent data sample to a timestamp attached to an acknowledge signal which it gets back from the receiver device, in order to find out which sample had been correctly received at the receiver side. If the sender does not receive a corresponding pair of timestamp and acknowledge signal until a predefined time interval has elapsed, it automatically resends at least one not acknowledged data sample.

Abstract: In a system for or method of data writing using a CPU and a plurality of memory banks connected to the CPU to enable the CPU to write the data thereon, a combination of data comprising data and their complement are written on a first memory bank and the same combination of data are written on a second memory bank, a sum of the combination of data written on the first and second memory banks is calculated, and when the sum of the combination of data written on one of the first and second memory banks is a specific value, it is determined that the data written on the one of the first and second memory banks are normal. With this, it becomes possible to surely determine whether the written data are normal or not, thereby enabling to enhance the data reliability.

Abstract: A turbo encoder is provided to be capable of improving its performance in the case that the redundancy is low. A first constituent encoder (1) of an output device of the turbo encoder inputs a data coding sequence (Xk) directly and outputs a redundant data sequence (Zk). A second constituent encoder (2) inputs data coding information (X?k) mixed with the data coding sequence by an interleaver (3), and outputs a redundant data sequence (Z?k). A buffer (4) holds the data coding information (X?k) mixed with the data coding sequence by the interleaver (3). Thus, the data coding sequence (Xk), the redundant data sequences (Zk), (Z?k) and the data coding information (X?k) held by the buffer (4) are output in this order.

Abstract: A Hybrid Automatic Retransmission Request (H-ARQ) technique is provided for Multi-Input Multi-Output (MIMO) systems. The technique changes the basis (V) upon retransmission, which helps reduce the error probability upon retransmission. This basis hopping technique provides for improved performance gain without significant increase in design complexity. In one embodiment, communication device (100) includes a receiver section (114) for receiving an acknowledgment (ACK) or a non-acknowledgment (NACK) signal in response to information transmitted by the transmitter section of the communication device. If a NACK is received, a new basis is selected from a set of basis stored in a basis set unit (110). The new basis that is selected is then used by a linear transformation unit (106) in the retransmission of the information.

Abstract: A method and apparatus are disclosed for performing maintenance operations in a system using address, data, and controls which are transported through the system, allowing for parallel and serial operations to co-exist without the parallel operations being slowed down by the serial ones. It also provides for use of common shifters, engines, and protocols as well as efficient conversion of ECC to parity and parity to ECC as needed in the system. The invention also provides for error detection and isolation, both locally and in the reported status. The invention provides for large maintenance address and data spaces (typically 64 bits address and 64 bits data per address supported).

Abstract: Provided are a method, system, and article of manufacture for recovery of application faults in a mirrored application environment. Application events are recorded at a primary system executing an instruction for an application. The recorded events are transferred to a buffer. The recorded events are transferred from the buffer to a secondary system, wherein the secondary system implements processes indicated in the recorded events to execute the instructions indicated in the events. An error is detected at the primary system. A determination is made of a primary order in which the events are executed by processes in the primary system. A determination is made of a modified order of the execution of the events comprising a different order of executing the events than the primary order in response to detecting the error. The secondary system processes execute the instructions indicated in the recorded events according to the modified order.

Abstract: An Automatic Retransmission reQuest (ARQ) data block reception apparatus and method in a communication system is provided. In the ARQ method, an ARQ feedback Information Element (IE) is transmitted to an ARQ data block transmission apparatus. The ARQ feedback IE includes a first field for indicating a Connection IDentifier (CID) of an ARQ connection, a second field for indicating the presence/absence of an additional ARQ feedback IE after the ARQ feedback IE, a third field for indicating a type of an Acknowledgement (ACK) MAP included in the ARQ feedback IE, a fourth field for indicating a Block Sequence Number (BSN) of an ARQ data block, and m ACK MAP fields. The m ACK MAP fields each include information indicating presence/absence of an additional ACK MAP field after a corresponding ACK MAP field, and an ACK MAP indicating success/failure in normal reception for each of n ARQ data blocks, wherein m and n each denote an integer greater than or equal to 1.

Abstract: A system and method for data storage in an array. A system includes a client coupled to a storage subsystem. The storage subsystem comprises data storage locations addressable as rows and columns in an array. Each column comprises a separate storage device. Each row includes redundant data. For a given row, a coordinating storage device receives data from the client, coordinates computation and storage of redundant data, and forwards data to other storage devices. In response to receiving data targeted for storage in a given storage location, a non-volatile, temporary storage device that is associated with the separate storage device that includes the given storage location buffers the received data. The coordinating storage device conveys a write completion message to the client in response to detecting that the data has been buffered in the non-volatile, temporary storage devices. At least two storage devices are coordinating storage devices in separate rows.

Abstract: A failover method for a cluster computer system in which a plurality of computers sharing a resource are connected by a heartbeat path for providing each computer with lines for monitoring operations of the other computers and a reset path. Resetting may be conducted based upon a registered priority for resetting the computers.

Abstract: A retransmission apparatus retransmits TS (Transport Stream) packets based on a received broadcast wave to a plurality of receiving apparatus through a network. The retransmission apparatus has a TS packet determination unit for determining whether a continuity of circulation counter values in the TS packets keeps in length equal to or more larger than a first predetermined threshold value N, and for retransmitting these TS packets when the determination is true, or for canceling these TS packets when the determination is false. Also, the TS packet determination unit determines whether a discontinuity of circulation counter values in the TS packets keeps in length equal to or more larger than a second predetermined threshold value T without retransmitting these TS packets, and sends an “off service” signal to a plurality of receiving apparatus when the determination is true.

Abstract: Provided are a system, and article of manufacture in which data is received at the first storage unit. A first information unit, a second information unit, and a third information unit are generated, wherein the first information unit, the second information unit, and the third information unit each include a portion of the received data and computed parity data. The first information unit is stored in the first storage unit at the first site. The second information unit is distributed to the second storage unit at the second site for storage. The third information unit is distributed to the third storage unit at the third site for storage.

Abstract: Embodiments include methods, apparatus, and systems for controlling of sparing in a storage system. In one embodiment, a method compares a first amount of time to complete sparing of data from a failed disk in a storage system with a second amount of time to complete a user request to the storage system in order to determine when to create a copy of the data from the failed disk.

Abstract: A method and a system for detecting and recovering a failure command are provided. The method is used in a native command queuing (NCQ) and at least includes the following steps. In step (a), several commands are executed on a disk simultaneously according to the NCQ. In step (b), whether a request time of the commands is longer than a waiting time is measured: if the request time is not longer than the waiting time, then step (a) is executed. In step (c), one command is chosen. In step (d), whether the chosen command is executed successfully is determined: if the chosen command is executed successfully, then step (f) is executed. In step (e), the chosen command is recovered. In step (f), whether all the commands of the NCQ are chosen is determined: if not all the commands are chosen, then another command is chosen and step (d) is repeated.

Abstract: Methods and apparatus for communicating and utilizing persistent allocation of resources are described herein. A base station can allocate persistent resources to a client station, and can associate the client station or persistent resource allocation with a particular shared NACK channel. The base station can monitor the NACK channel for a NACK indicating a map error. The base station can also monitor the resource allocation to implicitly determine a map error. The base station can resend one or more persistent resource allocation information elements in response to the NACK or implicit error determination. A client station having a persistent resource allocation can monitor persistent resource allocation information elements in map messages and can indicate failure to receive a persistent resource allocation information element in a NACK message on a preassigned share NACK channel.

Abstract: A hybrid ARQ retransmission method in a communication system, wherein data packets consisting of symbols encoded with a forward error correction (FEC) technique prior to transmission are retransmitted based on an automatic repeat request and subsequently combined with previously received data packets the symbols of said data packets being modulated by a mapping unit employing a predetermined signal constellation. The retransmitted data packets being retransmitted in form of a selected one of a plurality of different redundancy versions. According to the invention the transmitted bits of the modulated symbols are reordered over the retransmissions in accordance with the selected redundancy version.

Abstract: A MIMO transmitting apparatus that achieves a flexible control in accordance with variation of a propagation environment to reduce the number of retransmissions. A buffer (104) temporarily stores transport bits, which have been interleaved, in preparation for retransmission. An intra-code-word interleaver (105) performs an interleave process by all of the bits included in the symbols to be simultaneously transmitted from a plurality of transmitting antennas. When performing an intra-code-word interleave process, the intra-code-word interleaver (105) performs the interleave process in accordance with an interleave pattern notified from an interleave pattern table (107). A counter (106) counts retransmission requests, and outputs the number of retransmissions to the interleave pattern table (107).

Abstract: A system and method for transmission control in a wireless communication system, including receiving data for transmission to a receiving device, and forwarding the data to a subordinate device. The method also includes initiating a timer, and generating a supplemental receipt indicator. If the intermediate device receives at least one of a receipt indicator and one or more subordinate supplemental receipt indicators before expiration of the timer, the intermediate device includes the generated supplemental receipt indicator with the receipt indicator or one or more subordinate supplemental receipt indicators, and sends the indicators to a next superordinate device. If the intermediate device does not receive at least one of a receipt indicator or one or more subordinate supplemental receipt indicators before the expiration of the timer, the intermediate device sends the generated supplemental receipt indicator to the next superordinate device.

Abstract: A system and program storage device for extracting data of a buffer after a failure of an operating system. An application is registered prior to the failure. The registering includes identifying a buffer in which the data to be extracted is stored prior to the failure. The buffer is reserved to maintain the data residing in the buffer as unchanged from initiation to completion of a fast reboot of the operating system. The fast reboot is responsive to the failure. An in-memory file is generated during the fast reboot, points to the data residing in the buffer, and is stored in volatile memory and not in persistent storage. The data is extracted via an instruction which is executed by the application after completion of the fast reboot, and which operates on the in-memory file.

Abstract: High speed differential copy can be implemented in the fail-back after disaster recovery when the data of the primary site is protected safely. When a restore command is issued, the common snapshots of the snapshots of the primary site and the secondary site are extracted as the base snapshot by comparing the log tables of the primary site and secondary site. The volume of the primary site is rolled back with the extracted snapshots. The latest snapshot of the volume of the secondary site is transmitted to the primary site and it is applied to the volume of the primary site to synchronize the volumes of the primary site and the secondary site.

Abstract: A method for executing a computer program on computing hardware, e.g., on a microprocessor, is provided, the computer program including multiple program objects and errors being detected in the method while running the computer program on the computing hardware. The program objects are subdivided into at least two classes, and multiple program objects are executed during one run, program objects of the first class being repeated when an error is detected and, when an error is detected in one program object of the first class, which has already been sent for execution, this program object of the first class is restarted instead of a program object of the second class after the other program objects of the first class of a run.

Abstract: A retransmission control scheme and a wireless communication apparatus wherein the efficiency of retransmission control is enhanced to further improve the system throughput. In this wireless communication apparatus (100), an error occurrence factor addressing part (140) receives information related to the error occurrence factor of a transmitted packet or information related to the schemes of forming or transmitting a retransmittal packet corresponding to that error occurrence factor, and switches, based on the received information, the schemes of forming or transmitting the retransmittal packet. In this way, the schemes of forming or transmitting the retransmittal packet can be switched in accordance with the error occurrence factor of the transmitted packet. At the end of receiving the retransmittal packet, therefore, the performing of a decoding processor the like in accordance with that scheme of forming or transmitting can enhance the efficiency of the retransmission control.

Abstract: Provided is a method of performing backup and recovery of data by using journaling, and performing management upon occurrence of a failure. The method includes: a first step of setting a recovery point indicative of the given time; a second step of creating an information of correspondence between the snapshot and the journal data which is required to restore data at the set recovery point time; a third step of detecting the occurrence of failure of the disk drive; and a fourth step of detecting the recovery point at which data cannot be restored due to the failure of the disk drive.

Abstract: A storage system maintains a journal and a snapshot of one or more data volumes. Two journal entry types are maintained, an AFTER journal entry and a BEFORE journal entry. Two modes of data recovery are provided: “fast” recovery and “undo-able” recovery. A combination of both recovery modes allows the user to quickly recover a targeted data state.

Abstract: A method of rebuilding a replacement drive used in a RAID group of drives is disclosed. The rebuilding method includes tracking data modification operations continuously during use of the drives. The method also includes saving the tracked data modifications to a log in a persistent storage, where the tracked data modifications are associated with stripe data present on the drives. Then, rebuilding a failed one of the drives with a replacement drive. The rebuilding is facilitated by referencing the log from the persistent storage, and the log facilitating reading only portions of stripe data from surviving drives and omitting reading of portions from the drives where no data was written. Thus, the rebuilding only rebuilds the stripe data to the replacement drive. Also provided is a zoning method, which enables logical zone creation from storage area networks.

Abstract: An apparatus and method for scheduling data distributions to or results information from, or collectively, “jobs” a plurality of data processing systems via a network. A connection to a target system is created. For each distribution, a session, which is an independent thread, is allocated from one of a plurality of pool of sessions and launched to effect execution of the job. Each pool corresponds to a predetermined priority level, and the session is allocated from the pool having the same priority level as the priority level of the job being scheduled. A connection supports a multiplicity of independent threads. In the event of an error, the session is released, and the scheduling of the aborted job is retried after a predetermined retry interval expires. After expiry of the retry interval, a callback method is invoked when the target system on which the scheduled job is executed becomes accessible.

Abstract: An embodiment of the invention is a client on a local area network that periodically and automatically evaluates its physical connectivity with the local area network, exercises local-network services such as DHCP, and verifies Internet connectivity and function by pinging one or more numerically specified IP addresses and by pinging one or more IP addresses specified by an FQDN (Fully Qualified Domain Name) known to the assigned DNS servers. An embodiment of the invention may include a plurality of client elements monitoring one or more networks. Functionality according to embodiments of the invention can send notices, automatically initiate action, and otherwise assist in, among other things, remote monitoring and administration of networks, and particularly wireless networks.

Abstract: The present invention relates to automatic repeat request (ARQ) in wireless communication systems wherein a coded message block is spread over a plurality of sub-carriers or components. According to the invention an equalizing HARQ method is introduced. The equalizing HARQ identifies (215) and retransmits (230) the most distorted parts of a received coded message block. In addition, the retransmitted parts can optionally be relocated (225) to components of higher quality, which ensures good retransmission quality for those badly distorted parts in the prior transmission. After a soft-bit combination in a receiving node, the final received codeword experience an equalized quality variation with low multi-state performance loss.

Abstract: There is provided a system having a plurality of information processing apparatuses, each of which comprises a storage device that stores, for each occurrence pattern of events to be detected, a plurality of tasks for respectively determining whether a plurality of conditions are fulfilled; a process determination section that, in response to occurrence of an event, reads a plurality of tasks corresponding to the occurrence pattern including the event from the storage device, and determines which information processing apparatus is caused to process each of the read tasks; a process execution section that processes a task determined to be processed by that information processing apparatus, and instructs another information processing apparatus to process a task determined to be processed by the other information processing apparatus; and a detection section that determines that the event has occurred in the predetermined occurrence pattern under a condition that process results of the processed task and the t

Abstract: A system for detecting one or more localized burst errors in a receiving message comprised of a plurality of codewords. The system comprises a trellis code decoder for decoding a receiving message with a plurality of codewords and calculating one or more cumulative metrics of a maximum likelihood path and one or more alternative paths from the receiving message, an error detection code (EDC) decoder for detecting existence of one or more errors in the decoded receiving message received from the trellis decoder, and a localized burst error detector activated by the EDC decoder upon detecting the existence of one or more errors in the decoded receiving message to identify at least one corrupted codeword among the plurality of codewords using the one or more cumulative metrics of a maximum likelihood path and the one or more alternative paths, wherein the system requests the re-transmission of the corrupted codeword.

Abstract: A method and apparatus are provided for enhancing the performance of storage systems to allow recovery after all types of suspensions in remote copy operations. Data is synchronized after an interruption in transfer between a first storage volume of a primary storage system and a first storage volume of a secondary storage system which also includes a second storage volume. After the interruption is detected, at the primary storage system, a record is provided of the data written onto the first storage volume of the primary storage system, and at the secondary storage volume a record is provided of the data written onto the first storage volume of the secondary storage system. Then, at least a partial copy of the record of the data written onto the first storage volume of the primary storage system is written onto the second storage volume. Using the copy, the first storage volume of the secondary storage system is synchronized with the second storage volume of the secondary storage system.

Abstract: A data processing system has a plurality of storage systems. In this system, data replication is performed at high speed and efficiency while maintaining data integrity. In addition, when failure has occurred in a configuration element, the time necessary to resume the data replication is reduced. In accordance with an instruction from first host computer, updating of replication-target data and creation of a journal are performed in a storage system A; and updating of replication data and creation of a journal are performed in a storage system B. A storage system C retrieves a journal from the storage system B in asynchronization with the updating, and performs updating of replication data. When failure has occurred in the storage system B, a journal-retrieving end is altered to the storage system, and the replication data is updated in accordance with the retrieved journal.

Abstract: A system and method is provided which allows for the dynamic interpretation of a transport block size field in a Layer 1/Layer 2 (L1/L2) control channel, such that for any first H-ARQ transmission, the transport block size indication field will indicate the size of the transport block. For any retransmission, the transport block size indication bits can be transformed into dedicated bits for indicating the RV used as it relates to circular buffering. A robust bit field for indicating new data transmission (e,g, new data indication (NDI)) is therefore introduced, and from a UE perspective it is possible to determine how to interpret the transport block size field.

Abstract: The present invention relates to a method for realizing HARQ in multi-carrier cell, comprising: when distributing high-speed shared resource for UE, Node B distributes the high-speed downlink packet service to N frequencies, and reports the information of the established physical channel, including the frequency information, to RNC and said UE; after Node B establishes the high-speed shared resource for said UE at N frequencies, it establishes N HARQ sub-entities on the HARQ entity built for said UE, each sub-entity independently processes the high-speed downlink packet service at one frequency; correspondingly, said UE also establishes N HARQ sub-entities on the HARQ entity; Node B configures parameters for each HARQ sub-entity and notifies the configuration information to RNC and said UE through upper-level signaling; Node B and UE complete their configuration for each sub-entity of HARQ entity according to the information, and realize the HARQ function in the service.

Abstract: The present invention relates to a transmitter and a receiver for a mobile communication system. The basic idea of the present invention is to target the number of HARQ transmissions that is required to be able to decode the transmitted data successfully and to only transmit HARQ feedback information if the decoding result differs from an expected result, wherein the expected result is based on the targeted number of required HARQ transmissions.

Abstract: A data communication method for puncturing of parity bits defining all parity data for a minimum code rate generated by an encoder is disclosed. The method initializes an accumulator associated with the parity bits to an initial value, and for each parity bit increments the accumulator by a increment value and determines if the accumulator has overflowed. If the accumulator overflows, at least one of the parity bits is selected for transmission.

Abstract: The present invention relates to a method for transmitting data packets from a mobile terminal to a base station using a hybrid automatic repeat request protocol and soft combining of received data. Further, the present invention provides a base station and a mo-bile terminal both configured to perform the respective method steps. Moreover, a communication system is provided which comprises at least one base station and at least one mobile terminal. In order to decrease the interference caused by retransmissions, the present invention suggests the use of separated channels for initial transmissions and their retransmissions. In order to decrease the interference caused by retransmissions, the present invention suggests the use of separated channels for initial transmissions and their retransmissions.

Abstract: A load balancer detects a server failure, and sends a failure notification message to the remaining servers. In response, one or more of the remaining servers may autonomically adjust their configuration parameters, thereby allowing the remaining servers to better handle the increased load caused by the server failure. One or more of the servers may also include a performance measurement mechanism that measures performance before and after an autonomic adjustment of the configuration parameters to determine whether and how much the autonomic adjustments improved the system performance. In this manner server computer systems may autonomically compensate for the failure of another server computer system that was sharing the workload.

Abstract: The present invention relates to a multiple antenna transmitting/receiving apparatus that performs a hybrid automatic repeat request, and a retransmission method thereof. An initial transmission signal is encoded into the form of an initial transmission matrix and transmitted to the receiving apparatus, the initial transmission matrix corresponding to a linear dispersion code, with a result of error checking performed on the initial transmission signal by the receiving apparatus. When an error is detected in the initial transmission signal, a first retransmission signal is generated by encoding the initial transmission signal in the form of a retransmission matrix and transmitted to the receiving apparatus. The retransmission matrix is formed of constituent elements of the initial transmission matrix but different from the initial transmission matrix, and corresponds to a linear dispersion code having the same capacity and diversity gain as those of the initial transmission matrix.

Abstract: Provided are an apparatus and method for transmitting data and an apparatus and method for receiving data, in which the transmission of uncompressed data over a wireless network can be performed by retransmitting an erroneous bit or a group of erroneous bits, if any, of each sub-packet including a number of bits or a number of groups of bits having different significance levels. The apparatus for transmitting data includes an error detection module which determines whether each of a plurality of portions of a transmitted packet having different significance levels is erroneous based on a received response packet; a data-packet generation module which generates a retransmission packet including one or more erroneous portions of the transmitted packet according to the results of the determination performed by the error detection module; and a communication module which transmits the retransmission packet through a communication channel.

Abstract: A communication apparatus is provided. The communication apparatus includes an image read unit which reads image data from a transmission document; a tag read unit which wirelessly reads tag data stored in a wireless tag corresponding to the transmission document; an image data generation unit, if the tag data includes mark data indicating that a mark is to be added to the image data, generates composite image data by combining the image data and mark image data based on the mark data; and a transmission unit which transmits the composite image data as transmission document data to an external apparatus.

Abstract: A method for an Automatic Repeat reQuest (ARQ) at a receiver in a Multiple Input Multiple Output (MIMO) system wherein when a received packet is erroneous and the erroneous packet is received from the weakest antenna in a Space Multiplexing (SM) mode, a first smallest number of retransmissions is computed to acquire a Signal to Noise Ratio (SNR) within or above an Adaptive Modulation and Coding (AMC) level. When the first number of the retransmissions is greater than a threshold, the sender is requested to retransmit the packets from the strongest antenna in the SM mode and when the first number of the retransmissions is smaller than the threshold, the sender is requested to retransmit the packets from the weakest antenna in the SM mode.