Survey on performance, reliability and future proposal of Cognitive Radio under wireless computing

In daily life internet plays a vital role in every aspects of web usage by the end users. Its essential purpose is information retrieval, packet transmission, communication between networks via wired and wireless mode. Subsequently wireless data networks and transmission are renowned by a fixed spectrum obligation policy and therefore that spectrum utilization becomes very significant one, in which new communication techniques are keep on increasing and the spectrum bandwidth remains limited because of unlicensed users. Cognitive radio is an innovatory technology to make use of the limited spectrum more successful. Cognitive Radio (CR) aspires to look up for the spectrum utilization by taking improvement of licensed user or primary user, which are so-called unused spectrum. Cognitive Radio has extensive applications together with dynamic spectrum access allocation and interference management, which will largely blow the NeXt Generation Network (xG) for wireless devices and networks. This new networking model is referred to as NeXt Generation (xG) Network as well as known as Dynamic Spectrum Access (DSA) and Cognitive Radio Networks. Eventually the performance and reliability of CR can be increased through the cross-layer design approach in the (xG) networks. In this paper, we carry out a survey on CR networks from various portions such as waveform, spectrum management and sensing, similarities between intelligent antenna and CR, performance and reliability evaluations etc.