Cognitive Radio Networks with Wireless Sensor Applications

** 无线传感器网络（WSNs）是快速发展的物联网的一部分，将在改变我们的生活中发挥重要作用。这些传感器的潜在数量将很快被部署，以执行简单到复杂的任务，例如自动控制智能家居中的热和光，以引导自动驾驶车辆和导弹。为这些潜在的众多无线传感器找到足够的无线电频谱是一个主要问题。虽然加拿大工业部正在努力分配更多的频率 * 波段，高达毫米波段，但许多研究人员的实验研究表明，* 已经分配的频谱通常未被充分利用25- 30%。** 认知无线电（CR）网络是一种新型的智能无线网络，其中认知（次要）用户被配置为与授权（主要）用户共存，而不会通过机会性频谱接入对他们造成有害的电磁干扰。成功实施公司责任周期有几个步骤。即，* 频谱感知（通过感知各种频谱参数和 * 频谱占用来实现），基于观察的分析和决策，以及 * 频谱利用（适应）。这些基本功能需要在认知无线电网络中重复执行。 * 无线传感器网络的另一个挑战是提供能量。这些传感器的电池管理和维护可能是一个令人望而却步的 * 昂贵的练习，因为他们的丰富。传感器的性能将随着剩余能量水平而恶化，死亡的传感器节点将影响整个网络的性能，特别是在多跳网络中。不适当的电池处置也会造成环境污染，长期下来危害健康。 * 能源问题可以通过能量收集来缓解。周围环境具有光、热、机械振动和电磁辐射形式的能量。特别是，认知无线传感器网络可以从主网络中获取能量。这种能量必须用 * 合适的传感器收集，可靠地存储，并用于无线数据传输 *，

**Wireless sensor networks (WSNs), part of the fast*emerging Internet of Things will be playing vital role in transforming our*lives. Potentially huge number of these sensors will soon be deployed to*perform simple to complex tasks such as automatically controlling heat and*light in smart homes to guiding autonomous vehicles and missiles. Finding*adequate radio spectrum of these potentially numerous wireless sensors is a*major issue. While Industry Canada is struggling to allocate more frequency*bands, up to mm wave bands, many researchers' experimental studies show that*already allocated spectrum is typically underused by 25-30%. *** ***Cognitive radio (CR) networks are a new form of*intelligent wireless network where, the cognitive (secondary) users are*configured to coexist with licensed (primary) users without causing harmful*electromagnetic interference to them by opportunistic spectrum access. There*are a few steps in the successful implementation of a CR cycle. Namely,*spectrum awareness (achieved through sensing various spectrum parameters and*spectrum occupancy), analysis and decision making based on the observation, and*spectrum exploitation (adaptation). These basic functions need to be carried*out repeatedly in a cognitive radio network.*** ***Another challenge in WSN is providing energy.*Battery management and maintenance of these sensors can be a prohibitively*expensive exercise because of their abundance. Sensors' performance will*deteriorate with the remaining energy level and dead sensor nodes will affect*the performance of an entire network, especially in multi-hop networks.*Improper battery disposal will also cause environmental pollution and health*hazardous in the long run. *** ***The energy issue can be alleviated by energy*harvesting. The ambience has energy in the forms of light, heat, mechanical*vibrations and electromagnetic radiations. Especially, cognitive WSN can harvest*energy from the primary network. This energy has to be collected with*appropriate transducers, stored reliably and used for wireless data*transmission w