Rajwinder Singh

Cognitive Radio New Dimension in Wireless Communication - State of Art

todays wireless communication environment, the Radio Frequency spectrum is occupied for different purposes like cellular, Television, military, emergency or satellite communication. The frequency spectrum used for cellular communication is getting over crowded with increasing number of subscribers and demand for high data rate text or video transmission, but the frequency spectrum in other wireless broadcast and communication is not utilized efficiently, example in Television broadcast band, some of frequency spectrum is vacant at some instant or for particular time. The vacant spectrum could be used in cellular communication, means the spectrum is borrowed from Television Broadcast band to be used for cellular communication. A borrow/use of spectrum from other licensed frequency bands will improve the efficiency of spectrum use. In this paper, aspects of Cognitive Radio and comparison of different sensing techniques and methods are discussed. Secondly, the layer architecture of Cognitive Radio is presented. Thirdly, hardware and software platforms are discussed for Cognitive Radio testing.

Advanced Multiresolution Wavelet Based Wideband Spectrum Sensing Technique for Cognitive Radio

An advance multiresolution wavelet based approach for wideband spectrum sensing for cognitive radio system is proposed in this paper. Prime focus is made on the coarse detection part for interweaved system, in which unoccupied spectrum can be used efficiently by the cognitive users. Quick and immediate shifting over the sensed vacant channel is extremely vital and is a challenging task. To overcome this issue, fast and efficient spectrum sensing technique is proposed for cognitive radios by improvising the Discrete Wavelet Packet Transform (DWPT) for multiresolution interweaved systems. This proposed scheme not only increases the system speed but also reduces complexity. Simulation results are used to analyse the system performance and numerical analysis for computing system complexity.

Different Aspect Grid Security; based on User Authenticity and Message-based Security Service: A Review

Today, individuals and institutions in science, research organization and industry are increasingly forming virtual organizations to pool resources and tackle a common objective. Massive amount of information has been passed not only confined into particular country but also spread out across the globe. Participants in virtual organizations commonly need to share resources such as data archives, computer cycles, and networks resources usually available only with restrictions based on the requested resource’s nature and the user’s identity. Thus, any sharing mechanism must have the ability to authenticate the user’s identity and determine whether the user is authorized to request the resource. Moreover polices regarding message integrity also a great impediment while passing through scalable region (possible active attacks). This paper described a draft over view of different security polices for achieving confidentiality, authenticity, authorization, and integrity as well. So in this study we account for the possible strain to get over above discussed security issues.

Workflow Scheduling in Cloud Computing

Cloud Computing offers wide computation and resource facilities for execution of various application workflows. Many different resources involved in execution of single workflow. Cloud Computing offers highly dynamic environment in which the system load and status of resource changes frequently. As the workload increases with increase in Cloud Services and clients there is a need to handle these requests or jobs. It needs to schedule them first to execute on different available VMs. The execution of cloud workflows faces many uncertain factors in allocating and scheduling workload. The first step is to provide an efficient workflow allocation model by considering the client’s requirements. Workflow scheduling model will schedule jobs in such a way that all the jobs will get executed taking minimal possible time, maintain QoS and satisfy client’s requirements. KEYWORD: VM(Virtual Machine),Cloud Computing, Workflow, Workflow Scheduling.