초록 ▼

A method of determining the actual transmission rate in a variable transmission rate communication system is provided, using error detection metrics. The received symbols are decoded assuming each possible rate, and then re-encoded to determine a symbol error rate for each possible rate. The possibl

A method of determining the actual transmission rate in a variable transmission rate communication system is provided, using error detection metrics. The received symbols are decoded assuming each possible rate, and then re-encoded to determine a symbol error rate for each possible rate. The possible transmission rates are then narrowed down using a simple measure of the likelihood of error, such as the CRC status determined for each rate. The symbol error rates are compared to either make a confident decision as to the actual transmission rate or to erase the frame. Rather than compare the values of the symbol error rates with predetermined thresholds, the method compares the differences between the symbol error rates for each possible rate with predetermined thresholds. This results in fewer erasures, even if the symbol error rates are low due to high signal to noise ratios.

대표청구항 ▼

A method of determining the actual transmission rate in a variable transmission rate communication system is provided, using error detection metrics. The received symbols are decoded assuming each possible rate, and then re-encoded to determine a symbol error rate for each possible rate. The possibl

A method of determining the actual transmission rate in a variable transmission rate communication system is provided, using error detection metrics. The received symbols are decoded assuming each possible rate, and then re-encoded to determine a symbol error rate for each possible rate. The possible transmission rates are then narrowed down using a simple measure of the likelihood of error, such as the CRC status determined for each rate. The symbol error rates are compared to either make a confident decision as to the actual transmission rate or to erase the frame. Rather than compare the values of the symbol error rates with predetermined thresholds, the method compares the differences between the symbol error rates for each possible rate with predetermined thresholds. This results in fewer erasures, even if the symbol error rates are low due to high signal to noise ratios. hitecture for receiving a request for the first data from the open system computer, and sending second data having the first data to the open system computer, wherein the second data is identified as track data by the mainframe computer, wherein the request for the first data includes location information of the first data in the disk device, and wherein the location information was sent from the mainframe computer to the open system computer. 3. A storage system according to claim 2, wherein the second data includes data according to CKD format. 4. A storage system according to claim 3, wherein a data field of data according to CKD format in the second data is selected in the open system computer, and the selected data field is sent to an application program being executed in the open system computer. 5. A storage system according to claim 3, wherein the second interface is Small Computer System Interface (SCSI). 6. A storage system according to claim 3, wherein the disk device has a plurality of blocks, and wherein the second data is stored on a plurality of blocks in the disk device. 7. A storage system according to claim 3, wherein the disk device is a SCSI device. 8. A storage system according to claim 1, wherein the second data includes data according to CKD format. 9. A storage system according to claim 8, wherein the first data is data selected from the second data in the second computer and the selected data is sent to an application program in the second computer. 10. A computer system comprising: a first computer; a second computer; and a storage system coupled to said first computer and said second computer, wherein said storage system comprises: a first interface according to count key data (CKD) for receiving first data from said first computer, a storage device for storing the first data, and a second interface according to a fixed block architecture for receiving a request for the first data from the second computer and sending second data having the first data to the second computer, and wherein the request includes location information of the first data in the storage device that was sent from said first computer to said second computer. 11. A computer system according to claim 10, wherein the second data includes data according to CKD format. 12. A computer system according to claim 11, wherein said second computer selects a data field of the second data for an application program being executed in said second computer. 13. A computer system comprising: a first program executed in a first computer; a second program executed in a second computer; and a storage system coupled to said first computer and said second computer, wherein said storage system comprises: a first interface according to count key data (CKD) for receiving first data from the first computer, a storage device for storing the first data, and a second interface according to a fixed block architecture for receiving a request for the first data from the second computer and sending second data having the first data to the second computer, wherein the request includes location information of the first data in the storage device that was sent from the first program to the second program. 14. A computer system according to claim 13, wherein the second data includes data according to CKD format. 15. A computer system according to claim 14, wherein the second program selects a data field of the second data for an application program being executed in said second computer. M) that is located remotely from the computer and that can access a remote persistent storage device (RPSD), the processing unit is operable to request that data be stored in a non-volatile storage medium, the LDIM is configured to receive the data from the processing unit, and the LDIM is operable to (a) issue a write request and transmit the data to the LPSD so that the LPSD will store the data on the non-volatile storage medium and (b) transmit the data to the RDIM using the network interface after receiving the data from the processing unit. 2. The computer of claim 1, wherein the LDIM transmits the data to the RDIM substantially concurrently with writing the data to the LPSD. 3. The computer of claim 1, wherein the LDIM is further operable to store the data or a pointer to the data if the LDIM cannot successfully transmit the data to the RDIM, thereby enabling the LDIM to send the data to the RDIM at a later time when the LDIM can successfully transmit the data to the RDIM. 4. The computer of claim 1, wherein the LPSD is a hard disk drive, the computer further comprises a disk adapter, and the LDIM is coupled to the processing unit through the disk adapter. 5. The computer of claim 4, wherein the LDIM comprises a connector and the LPSD is coupled to the LDIM through the LDIP's connector. 6. The computer of claim 4, wherein the LDIM receives the data directly from the disk adapter and transmits the data to the LPSD through the LDIM connector to which the LPSD is connected. 7. The computer of claim 1, wherein the LDIM is coupled to the processing unit through a standard persistent storage device interface. 8. The computer of claim 1, wherein the standard persistent storage device interface is one of the ATA interface, SCSI interface, ST-506/412 interface, ESDI interface, IDE interface, ATAPI interface, ATA-E and EIDE interface. 9. The computer of claim 1, wherein, when the processing unit issues a non-data request, the non-data request is received by the LDIM and, in response to receiving the non-data request, the LDIM returns a response to the processing unit. 10. The computer of claim 1, further comprising a motherboard, wherein the processing unit is installed on the motherboard and the LDIM is connected to the motherboard by a cable. 11. In a computer having an operating system that receives from an application a request to store data on a local persistent storage device (LPSD) and that is configured to send the request and the data to a device driver for the LPSD, with the device driver being operable to issue the request and the data to a disk adapter or to a basic input/output system (BIOS), a method comprising the steps of: receiving the request and the data directly from the device driver; and in response to receiving the request and the data from the device driver, performing the steps of: issuing a write request to the LPSD; and transmitting a write request message to a system located remotely from the computer, wherein the write request message includes the data and an indication that the data should be written to a data storage medium. 12. The method of claim 11, wherein the request issued from the device driver includes a first address and the message transmitted to the system located remotely from the computer includes a second address, wherein the second address is a function of the first address. 13. The method of claim 12, wherein the second address is the same as the first address. 14. The method of claim 11, wherein the steps of issuing the write request to the LPSD and transmitting the write request message are performed substantially concurrently. 15. The method of claim 11, further comprising the steps of: receiving a non-data request directly from the device driver; and in response to receiving the non-data request, sending a response directly back to the device driver. 16. In a computer having a device driver, wherein the device driver receives a request to store data on a loca l persistent storage device (LPSD), and wherein the device driver is configured to issue the request to a disk adapter, and the disk adapter is configured to send the request to a controller of the LPSD, a method comprising the steps of: receiving a request directly from the disk adapter, wherein the request requests that data be written; and in response to receiving the request, performing the steps of: issuing a write request to the LPSD; and transmitting a write request message to a system located remotely from the computer, wherein the write request message includes the data and an indication that the data should be written to a data storage medium. 17. The method of claim 16, wherein the request issued from the device driver includes a first address and the message transmitted to the system located remotely from the computer includes a second address, wherein the second address is a function of the first address. 18. The method of claim 17, wherein the second address is the same as the first address. 19. The method of claim 16, wherein the steps of issuing the write request to the LPSD and transmitting the write request message are performed substantially concurrently. 20. The method of claim 16, further comprising the steps of: receiving a non-data request directly from the device driver; and in response to receiving the non-data request, sending a response directly back to the disk adapter. 21. In an environment where a device comprises a processor and a local persistent storage device (LPSD), a method for managing the LPSD's data image, comprising the steps of: copying at least a portion of the data image; storing the copied portion of the data image on a remote persistent storage device (RPSD) located remotely from the device; receiving a request to write data to the LPSD, wherein the request was transmitted by the processor; and in response to receiving the request, performing the steps of: issuing a write request to the LPSD; and transmitting a write request message to a system located remotely from the computer, wherein the message includes the data and wherein the system is operable to write the data the RPSD. 22. The system of claim 21, wherein the LPSD is a hard disk drive that comprises a hard disk. 23. The method of claim 21, further comprising the steps of: receiving a non-data request transmitted from the processor; and in response to receiving the non-data request, sending a response back to the processor. 24. The method of claim 21, wherein the steps of issuing the write request to the LPSD and transmitting the write request message are performed substantially concurrently. 25. A local data image manager, comprising: interface means for interfacing to a persistent storage device (PSD); receiving means for receiving commands and data, wherein the commands comprise read commands, write commands, and non-data commands; means for issuing a write command to the PSD after the receiving means receives data and a write command; and means for transmitting a write request message to a remote system located remotely from the local data image manager after the receiving means receives data and a write command. 26. The local data image manager of claim 25, wherein said means for receiving said commands receives said commands from a disk adapter. 27. The local data image manager of claim 25, wherein said PSD is a hard disk drive that comprises a hard disk. 28. The local data image manager of claim 27, wherein the receiving means comprises interface means for interfacing with a disk adapter. 29. The local data image manager of claim 28, wherein the interface means comprises a 40 pin IDE flat cable connector. 30. A system, comprising: a first circuit board; first processing means disposed on the first circuit board; a first local persistent storage device (LPSD) connector operable to connect to an LPSD, the LPSD connector being disposed on the first circuit board; a second ci rcuit board; second processing means disposed on the second circuit board, the second processing means being programmed to emulate an LPSD; a connector, disposed on the second circuit board, being connected to the LPSD connector disposed on the first circuit board; transmitting means disposed on the second circuit board for enabling the second processing means to send messages to and receive messages from a remote system that is located remotely from the system and that can access a remote persistent storage device (RPSD), and a second LPSD connector, the second LPSD connector being disposed on said second circuit board. 31. The system of claim 30, further comprising an LPSD, wherein the LPSD is connected to the second LPSD connector. 32. The system of claim 31, wherein the LPSD connected to the second LPSD connector is a hard disk drive. 33. The system of claim 31, wherein the LPSD connected to the second LPSD connector is a drive for writing data to compact disc. 34. The system of claim 33, wherein the second processing means receives read, write, and non-data commands issued from the first processing unit. 35. The system of claim 34, wherein the second processing means issues a write command to the LPSD connected to the second LPSD connector in response to receiving a write command issued from the first processing unit and also transmits a write request message to the remote system in response to receiving the write command. 36. The system of claim 35, wherein the second processing means issues the write command to the LPSD and transmits the write request message substantially concurrently. 37. In a system having an local data image manager (LDIM) and a local persistent storage device (LPSD) connected to the LDIM, a method, comprising: receiving, at the LDIM, data, a request to store the data, and a first value for identifying a segment of a data storage medium; and in response to receiving the data, the request to store the data, and the value, performing the steps of: sending to the LPSD from the LDIM, the data, a second value for identifying a segment of a data storage medium, and a request to store the data; and transmitting, via a network, a message to a remote system, wherein the message includes the data and a request for the remote system to store the data. 38. The method of claim 37, wherein the first value is a sector value for identifying a sector. 39. The method of claim 37, wherein the LPSD is a hard disk drive. 40. The method of claim 37, wherein the sending and transmitting steps are performed substantially concurrently. 41. The method of claim 37, further wherein the second value is not equal to the first value. 42. The method of claim 41, further comprising the step of determining the second value based on the first value. 43. The method of claim 37, wherein the LPSD comprises one of a hard disk, a read/write CD, a ZIP disk, a JAZ disk, and a floppy disk. 44. The method of claim 37, wherein the data included in the message transmitted to the remote system is encrypted data.