Enhanced Dynamic Frequency Hopping Performance in Cognitive Radio IEEE 802.22 Standard

IEEE 802.22 is a Cognitive Radio based standard designed for Wireless Regional Area Networks (WRAN) for the purpose of providing wireless broadband access to rural and remote areas. The standard relies on the utilization of the unoccupied spectrum that became available after the TV signal was converted from analog to digital. In this thesis, we present an enhanced scheme for the operation of the Dynamic Frequency Hopping (DFH) technique in the IEEE 802.22 standard for WRANs. The performance of the DFH is analyzed thoroughly for various types of channels and for a Multiple-input Multiple-output (MIMO) systems. The core of this research is based on the coexistence of the incumbent users and the WRANs in the TV white spaces (TVWS). The proposed technique, aims at protecting the licensed users from interfering with the cognitive broadband access in the TV spectrum. In order to achieve that, spectrum sensing is performed in the intended working channel in DFH while spectrum monitoring with the energy-ratio (ER) algorithm is applied during the WRAN data transmission in the currently working channel. Hence, in the DFH-ER algorithm the reappearance of an incumbent user in a band occupied by the WRANs would be detected immediately, providing interference free performance for the licensed user as well as reliable data transmission for the unlicensed one. Simulation results of the proposed DFH-ER technique compared to the conventional DFH scenario exemplify the enhancement of the WRAN data transmission while protecting the incumbent users

A Review and Evaluation of Queue Based Control Power Efficient Spectrum Allocation Method for LTE Networks

The cognitive radio based wireless regional area networks (WRAN) is nothing but IEEE-802.22 standard. IEEE 802.22 standard enables opportunistic access to in-use or free 900 MHz TV sub bands by secondary networks. There are many other standards presented; however there is no efficient methods for cognitive networks like LTE for channel access and bandwidth utilization. The existing methods for spectrum access in LTE networks, however most of methods are not flexible, power consuming. Also in literature, we studied that existing methods of spectrum allocation in LTE networks does not efficiently achieve the tradeoff between network QoS (Quality of Service) and power efficiency. The goal of this paper is to present the review on such different spectrum efficiency techniques for LTE networks and then evaluate the recent Queue Based Control (QBC) for power efficient spectrum allocation with its limitations and benefits. QBC approach helps in solving the research problem related to the energy efficiency as well as QoS efficiency to some extent. There are two variants of QBC method such as QBC1 and QBC2 with different objectives and configurations. We are evaluating both this approach on LTE network which is composed of Spectrum Manager (SM), evolved Nodes B (eNBs) and number of user’s. The experimental work is conducted using network simulator (NS2) for delay and energy consumption parameters

Modified Algorithm of Dynamic Frequency Hopping (DFH) in the IEEE 802.22 Standard

IEEE 802.22 Cognitive Wireless Regional Area Networks is a first standard of wireless terrestrial system relying on cognitive radio concept and operating as an opportunistic system in the the vacant unoccupied frequency spaces of the licensed TV-frequency band. Concept of the proposed standard assumes special functionality to protect the operation of the primary licensed subscribers. Dynamic Frequency Hopping is the mechanism for providing connectionless operation of Wireless Regional Area Networks systems while ensuring protection of transmissions from the primary users. During its operation regular time gaps appear on the involved frequency channels. This paper introduces the concept of the efficient reuse of the vacant frequency resources appearing when using the Dynamic Frequency Hopping mode. The scheme for consecutive-parallel inclusion of the new Dynamic Frequency Hopping Communities-members in the Dynamic Frequency Hopping mode is presented. The proposed approach allows significantly decrease time of inclusion the new members into a new Dynamic Frequency Hopping Communities. © Springer International Publishing Switzerland 201