第一位嘉宾演讲信息：
报告题目：Low-Power Transmission in Energy-Harvesting Wireless Sensor Networks
报 告 人: Dr. Kai Yang（贝尔实验室，美国）
报告时间: 2011年12月 12日（周一）14:45～15:30
报告地点: 威廉williamhill体育 延长校区 科技楼8楼报告厅
邀 请 人: 王廷云 教授
Abstract：
Wireless sensor networks have been used in a wide variety of applications including smart building, healthcare systems, and sensing & monitoring in smart power grids. Traditional wireless sensors rely on batteries to collect and transmit data. The limited capacity of the battery, however, could severely restrict the lifespan of a sensor. Energy harvesting is one of the most effective means to prolong the lifetime of the wireless sensor network. In this talk, I will first survey the basics of energy harvesting technologies, including potential energy sources, energy harvesting and storage devices, and the challenges against the successful operation of the energy-harvesting sensor network. I will then discuss in details two illustrative examples of low-power wireless transmission technologies for energy-harvesting sensor networks, namely the battery-aware adaptive modulation schemes with stringent delay constraint and solar-powered energy-efficient wireless transmissions. Simulation results based on real data collected from experiments will also be demonstrated.
第二位嘉宾演讲信息：
报告题目：Real-Time Optical OFDM for Next Generation PONs
报 告 人: Professor Jiangming Tang（Bangor University，英国）
报告时间: 2011年12月 12日（周一）15:30～16:15
报告地点: 威廉williamhill体育 延长校区 科技楼8楼报告厅
邀 请 人: 王廷云 教授
Abstract：
Driven by various emerging bandwidth-hungry services, the end-users' demand for transmission bandwidth increases more than 70% year on year. As a direct result of such a rapid traffic growth, according to Infonetics, the global telecommunication equipment sales in the access network sector sequentially grow by 71% per year. It is estimated that by 2014 the access equipment market in APAC alone will exceed $2 billion with China dominating at approximately 90% of the market size. The existing copper cable-based "last-mile" access networks are, however, only capable of sustaining at most 50Mb/s per subscriber and have become the main obstacles to providing the ultra-wide bandwidth services required in the near future. Passive optical networks (PONs) have been widely considered to be a promising strategy to enable each individual end-user to enjoy >1Gb/s everywhere. Cost effectiveness and flexibility are the crucial challenges for future mass deployment of PONs. To solve the challenges, great research and development effort has been expanded on exploring cost-effective, "future-proof", flexible technical solutions to satisfy future end-users' requirements.
As far as we are aware, Bangor University is the first and only institute in the world that has experimentally demonstrated a series of ground-breaking end-to-end real-time OOFDM transceivers at record-high speeds of up to 11.25Gb/s with essential functionalities such as adaptive bit/power loading, built-in signal synchronization, on-line performance monitoring and live parameter optimization, using off-the-shelf, low-cost electrical/optical components in simple intensity modulation and direct detection (IMDD) transmission systems based on standard single-mode fibres (SSMFs) and multi-mode fibres (MMFs). In this talk, our major world-first OOFDM research achievements made within 2010 and 2011 will be extensively reviewed in terms of the following key areas: a)experimental demonstrations of adaptive OOFDM transceivers with capabilities of automatically adopting to component/system imperfections; b)significant improvements in OOFDM transceiver cost-effectiveness by utilizing low-cost VCSELs/RSOAs as optical intensity modulators; c)simple and effective techniques capable of considerably improving optical power budgets of IMDD PON systems using directly modulated lasers; d) a number of novel, high-speed and accurate OOFDM synchronization techniques with added physical layer functionalities; e) OOFDM PON network architecture simplification, and f) experimental demonstrations and performance optimizations of real-time OOFDM multiple access (OOFDMA) PONs with adaptive dynamic bandwidth allocation. The results strongly indicate that OOFDM is feasible for mass deployment for cost-sensitive PON scenarios.
