Biblio

Visible light communication is a solution for high-security wireless data transmission. In this paper, we first analyze the potential vulnerability of the system from eavesdropping outside the room. By setting up a signal to noise ratio threshold, we define a vulnerable area outside of the room through a window. We compute the receiver aperture needed to capture the signal and what portion of the space is most vulnerable to eavesdropping. Based on the analysis, we propose a solution to improve the security by optimizing the modulation efficiency of each LED in the indoor lamp. The simulation results show that the proposed solution can improve the security considerably while maintaining the indoor communication performance.

Physical impairments in long-haul optical networks mandate that optical signals be regenerated within the (so-called translucent) network. Being expensive devices, regenerators are expected to be allocated sparsely and must be judiciously utilized. Next-generation optical-transport networks will include multiple domains with diverse technologies, protocols, granularities, and carriers. Because of confidentiality and scalability concerns, the scope of network-state information (e.g., topology, wavelength availability) may be limited to within a domain. In such networks, the problem of routing and wavelength assignment (RWA) aims to find an adequate route and wavelength(s) for lightpaths carrying end-to-end service demands. Some state information may have to be explicitly exchanged among the domains to facilitate the RWA process. The challenge is to determine which information is the most critical and make a wise choice for the path and wavelength(s) using the limited information. Recently, a framework for multidomain path computation called backward-recursive path-computation (BRPC) was standardized by the Internet Engineering Task Force. In this paper, we consider the RWA problem for connections within a single domain and interdomain connections so that the quality of transmission (QoT) requirement of each connection is satisfied, and the network-level performance metric of blocking probability is minimized. Cross-layer heuristics that are based on dynamic programming to effectively allocate the sparse regenerators are developed, and extensive simulation results are presented to demonstrate their effectiveness.