A loop-back WDM-PON based on a RSOA has lots of merits, however one-level of the upstream signal has downstream information under OOK modulation. These effects make difficult to define decision threshold and estimate BER. In order to solve this, we propose a mathematical model of remodulated OOK signal and experimentally demonstrate BER performance with the near optimum decision threshold achieved by the proposed model.

Due to the continuous growth of wireless communication technology and mobile equipment, the need for storing and processing data of moving objects arises in a wide range of location-based applications. In this paper, we propose a new spatio-temporal index structure for moving objects, namely the TPKDB-tree, which supports efficient retrieval of future positions and reduces the update cost.