Set Partitioning in Hierarchical Trees (SPIHT) is a highly efficient technique for compressing Discrete Wavelet Transform (DWT) decomposed images. Though its compression efficiency is a little less famous than Embedded Block Coding with Optimized Truncation (EBCOT) adopted by JPEG2000, SPIHT has a straight forward coding procedure and requires no tables. These make SPIHT a more appropriate algorithm for lower cost hardware implementation. In this paper, a modified SPIHT algorithm is presented. The modifications include a simplification of coefficient scanning process, a 1-D addressing method instead of the original 2-D arrangement of wavelet coefficients, and a fixed memory allocation for the data lists instead of a dynamic allocation approach required in the original SPIHT. Although the distortion is slightly increased, it facilitates an extremely fast throughput and easier hardware implementation. The VLSI implementation demonstrates that the proposed design can encode a CIF (352288) 4:2:0 image sequence with at least 30 frames per second at 100-MHz working frequency.

A novel distributed dynamic regional location management scheme called MORR (Mobility Oriented Regional Registration) is proposed for Mobile IP to improve the signaling traffic cost of a mobile node. This improvement is achieved by adjusting each mobile node's optimal regional domains according to its mobility behavior. With Mobile IP, the capricious mobility and variable traffic load of a mobile node has an impact on its average signaling traffic cost. In this paper, the mobility of all mobile nodes is classified into two modes: random mobility mode and regular mobility mode. We develop new analytical models to formulate the movement behavior and mathematically evaluate their characteristics when applied to these two modes. MORR has the adaptability to manipulate various mobility modes of each mobile node in dedicated ways to determine an optimal regional domain of this mobile node. Simulation results show that anywhere from 3 to 15 percent of the signaling cost is saved by MORR in comparison with the previous distributed dynamic location management schemes for various scenarios.