عنوان پایان‌نامه
طراحی بین لایه ای در سیستمهای مخابراتی بی سیم اقتضایی با انرژی محدود
- رشته تحصیلی
- مهندسی برق-مخابرات-سیستم
- مقطع تحصیلی
- کارشناسی ارشد
- محل دفاع
- کتابخانه دانشکده برق و کامپیوتر شماره ثبت: E1537;کتابخانه مرکزی -تالار اطلاع رسانی شماره ثبت: 40528
- تاریخ دفاع
- ۱۴ اسفند ۱۳۸۶
- دانشجو
- هما حسین مردی
- چکیده
- چکیده ندارد
- Abstract
- Wireless ad hoc networks (WANETS) are composed of a collection of wirelessly communicating devices with no prearranged infrastructure. In such networks, the devices (nodes) are often powered by battery and energy efficient operations are critical to prolong the lifetime of the connections. As an important application in WANETS, multicasting involves transferring data from a source node to a subset of nodes in the network. This thesis addresses the problem of lifetime maximization for the general case of multicast connections in WANETS based on a cross layer approach, and considers unicast and broadcast as special cases of multicast. We consider the optimized joint design of the physical, medium access control, and network layers to maximize the lifetime of energy constrained wireless ad hoc networks for multicast applications. When the transmission rates of the links are constant, using network coding at the network layer, the problem of computing maximum lifetime multipath flow is formulated as a linear optimization problem for استریمینگ and زمان واقعی application with multicast rate guarantee and nonlinear optimization problem for دانلود application without multicast rate guarantee. We consider two types of lifetime definitions; first node failure and multicast functionality to maximize the network lifetime. When rate control is available, we introduce another algorithm that exploits this additional degree of freedom to further enhance the network life time. As another improvement we consider directional antenna and provisioning of multiple simultaneous requests. Simulation results are provided assessing the effectiveness of the proposed algorithms.
