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In this paper, we propose two channel allocation schemes for supporting voice and multimedia traffic in hierarchical cellular systems. They are guaranteed to satisfy the required quality of service for multimedia traffic in accordance with their characteristics such as a mobile velocity for voice calls and a delay tolerance for multimedia calls. In the first, only slow-speed voice calls are allowed to overflow from macrocell to microcell and only adaptive multimedia calls can overflow from microcell to macrocell after reducing their bandwidth to the minimum channel bandwidth. In the second, in addition to the first scheme, non-adaptive multimedia calls can occupy the required channel bandwidth through reducing the channel bandwidth of adaptive multimedia calls. The proposed schemes are analyzed using the 2-dimensional Markov model. Through computer simulations, it is shown that the proposed schemes yield a significant improvement in terms of the forced termination probability of handoff calls. In particular, the second decreases the blocking probability of new calls as well as the forced termination probability of handoff calls.
We theoretically evaluate the prediction efficiency of the overlapped block motion compensation (OBMC) compared with the conventional non-overlapped approach. Based on the one-dimensional signal model characterized by the AR(1) process and first-order polynomial motion, a condition under which the performance of the OBMC is better, and an optimum window function are derived. From the results, we discuss and analyze several properties of the OBMC, some of which have been experimentally reported in the literature.