Applied Mechanics and Materials Vols. 303-306

Abstract: All-optical WDM networks are the most promising candidate for the next generation wideband backbone networks. To improve the utilization of wavelength, TDM technology is introduced into it. The routing, wavelength and time-slots assignment (RWTA) problem was studied in such time-space switched networks. A new adaptive algorithm was proposed which adopt adaptive network link weights and distribute slots of the session request on multiple different wavelengths adaptively with the remainder resource of the network. The effectiveness of the proposed algorithm is demonstrated by simulations and results show the better performance.

Abstract: Bluetooth is a short-range wireless technology that operates in the 2.4GHz unlicensed ISM band, so it will inevitably encounter the interference from other wireless systems and other Bluetooth piconets. Because of the flexible, efficient and reliable spectrum access by adapting the radio’s operating characteristics to the real-time conditions of the environment, cognitive radio technology is apply in Bluetooth network. In this paper, a novel cognitive frequency hopping (CFH) scheme based on channel quality detection is proposed. The coexistence mechanism of Bluetooth network and link quality detection method is described and discussed. Simulation results shown the performance of the proposed CFH system is improved.

Abstract: We review key advanced access technologies for 100G optical networking. These include novel candidate optical access for 100G optical networking, Nodal network and Architecture Choice, and device technologies.

Abstract: With the popularity and the development in-depth of Android, the applications of intelligent control using Android are also increasing rapidly. In this paper, we propose the design of TCP/IP wireless communication system based on the Android operating system. We send TCP control signal to an embedded network-to-serial module by Android smart phone and wireless network. The module can convert TCP protocol to TTL level, which the microcontroller serial can accept, then the high-low control signals from the microcontroller control the toy car’s motor to forward and reverse, then we achieve that the car can go forward, retreat, turn left, turn right and stop.

Abstract: With the booming of wireless communication technology, there is an increasing adoption of mobile advertising. In mobile advertising fields, most spillover effect studies are cross-sectional analysis measuring only immediate effects, which might underestimate total magnitude in the long run. Complementary to these studies, we employ a company archival dataset to explore LBAs’ (Location Based Advertisings) and PUAs’ (Pop-up Advertisings) long term spillover effects in a mobile commerce context. Designed for promoting mobile movie sales, these two advertising channels generate data business sales because of spillover effects. The developed VARX model quantifies spillover effects of LBA and PUA in both short and long terms. These findings advance mobile advertising literatures and make important implications for marketing managers using mobile commerce.

Abstract: With the rapid development of mobile internet, more and more frequency band will be needed to meet the requirement of high data speed. The system coexistence between mobile system and broadcast system is studied, including the scenarios, models, simulation results, related analysis, and finally the solution to resolve the coexistence is given. In urban, an additional 37dB isolation between broadcast system and mobile base station should been satisfied. And an additional 15.7dB is needed between mobile base station and broadcast receiver.

Abstract: Due to the lower channel utilization in conventional wavelength-routed networks, TDM technique is implemented on top of WDM to achieve a WDM-TDM network. RWTA problem in WDM-TDM networks is discussed. With the idea that assigned time-slots of one session can be distributed in multiple different wavelengths and the objective of minimizing network blocking probability, a RWTA algorithm called MUMD was proposed for dynamic traffic in mesh single-fiber networks. Then we demonstrate the performance of the proposed MUMD algorithm through numerical simulation. The results show that MUMD can efficiently optimize the network blocking performance, thereby optimize the resource utilization.

Abstract: The modified propagator method(MPM) improves the performances of DOA estimation, but compared with the propagator method (PM), the computational loads increase, especially under large number of antenna array elements condition. This paper studies the principle of using unitary transform to rearrange the propagator, and proposes unitary transformed MPM(UMPM) in order to decrease the computational loads by real-valued computation. The simulation results show that the proposed algorithm can achieve superior precision and lower computational loads than PM, MUSIC and MPM.

Abstract: We propose visible light communication 2D-OCDMA system for indoor communication. We first discuss about the system model, and also discuss about the construct of 2D-OOC code with 2-D OCDMA VLC system and 2-D OCDMA VLC with MWOOC. Compare it with 1D OOC. And we also give some analysis the capacity of 2D-OCDMA in VLC. From the analysis the structure of the 2D-OCDMA is complicated but using 2D-OCDMA can enhance the capacity of the system in the room. More work should be done in the future on this research.

Abstract: A low-complexity echo canceller integrated with vocoder is proposed in this paper to speed up the convergence process. By making full use of the linear prediction parameters retrieved from decoder and the voice active detection feature of the vocoder, the new echo canceller avoids the need to calculate decorrelation filter coefficients and prewhiten the received signal separately. Simulation results show performance improvement of the proposed algorithm in terms of convergence rate and echo return loss enhancement.