Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information Send comment regarding this burden estimate or any other aspect of this 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED 4. TITLE AND SUBTITLE Cross-Layer Exploitation of MAC Layer Diversity in Wireless Networks 5. FUNDING NUMBERS F49620

The fundamental mode characteristics of hybrid metal‐insulator‐metal plasmonic waveguide (HMIMPW), consists of a high‐index layer sandwiched between two spacer/low‐index and metal layers, has been explored to achieve relatively high power density with smaller effective mode area in low‐index waveguide region at the wavelength of 1550 nm. The HMIMPW has the advantage of low power loss with relatively large propagation distance, of order of several tens of λ. The simulation results have demonstrated that with spacer thickness of 10 nm, significantly higher confinement of optical mode power (> 65%) can be realized in the spacer region of HMIMPW with relatively smaller effective area of 0.0060 μm2 together with the power density > 200 μm−2. This type of analysis and results are very desirable for several specific applications, like optical sensing, nonlinear optics, optical manipulations. Further, the investigations on crosstalk performance between two parallel HMIMPWs have been addressed in order to realize the high integration density over the photonic chip. The decoupling separation of nearly 560 nm has been accomplished with the thicknesses of low‐ and high‐index regions, respectively, of 10 and 50 nm.

No abstract

This paper presents a performance study of the distributed coordination function (DCF) of 802.11 networks considering erroneous channel and capture effects under non-saturated traffic conditions employing a basic access method. The aggregate throughput of a practical wireless local area network (WLAN) strongly depends on the channel conditions. In a real radio environment, the received signal power at the access point from a station is subjected to deterministic path loss, shadowing, and fast multipath fading. The binary exponential backoff (BEB) mechanism of IEEE 802.11 DCF severely suffers from more channel idle time under high bit error rate (BER). To alleviate the low performance of IEEE 802.11 DCF, a new mechanism is introduced, which greatly outperforms the existing methods under a high BER. A multidimensional Markov chain model is used to characterize the behavior of DCF in order to account both non-ideal channel conditions and capture effects.

No abstract