Multilevel recording has been demonstrated to significantly increase the linear densities achieved with standard methods of binary encoding in optical data storage systems. In this paper we introduce the theoretical concepts and practical coding aspects behind multilevel optical recording system. We show that there are three-stage coding flow and explain how to design and implement the encoder. As an example we give a 5th-power finite state transition diagram of q=8 RLL (2, 10) encoder and compute its adjacent matrix. Especially we discuss the implement method to quickly search decoding table of slider decoder by way of computing the least Hamming distance.
A calorific equilibrium equation is used to derive the relativities of optimum recording power and pulse waveform parameters in various disc scanning velocities. Based on the model, a new recording parameters calibrating flow is given as a referenced process. A number of optical recording examples have been examined in detail, and the results have been compared with those calculated data by use of a general summation approach.
A iSCSI-based CD mirroring server (iCDMS) has been developed and tested. Firstly, the iCDMS can automate to concurrently mirror multi- CD with multi- CD drivers, and the CD includes VCD, DVD, and so on. Secondly, the iCDMS can provide both of the file I/O and the block I/O services by an iSCSI module, which converges the NAS and SAN advantages, as high performance and data sharing across platforms. Thirdly, the iCDMS greatly improves the I/O speed by Zero Copy mechanism. Fourthly, the iCDMS implements automatically - allocating I/O bandwidth for different users and applications by enriching the metadata operating semantic of the CD server, and allocate a wider bandwidth for applications that has higher priority, changing the old average allocating bandwidth pattern. Finally, the iCDMS improves paralleled file I/O performance with a parallel FTP server module. In the experiments, the iCDMS has ultra-high-throughput for both of the file I/O requests and the block I/O requests