International Journal of Mobile Network Design and Innovation (4 papers in press)
Hybrid Accuracy-Time Trade-off Solution for Spectrum Sensing in Cognitive Radio Networks
by Albena Mihovska, Antoni Ivanov, Vladimir Poulkov, Ramjee Prasad
Abstract: The rise of cognitive radio systems as a concept for future networks has seen a great amount of scientific effort in recent years. Appropriately, much attention is given to how the vital function of spectrum sensing should be executed. The cognitive radio device is required to be able to evaluate the spectral environment properly so that it may not create additional interference to the primary users. There is the need of optimization of the speed of the process so that the spectrum holes can be utilized. The sensing accuracy and sensing time are conflicting parameters, therefore, a suitable trade-off is necessary for an optimal efficiency. We propose a dual-approach solution. The decision about the spectrum occupancy is made using the measured signal-to-noise ratio (SNR) and the received signal levels as inputs in a fuzzy logic algorithm. The result is then compared with the one acquired using the statistical method. Finally, an optimal balance between the sensing time and accuracy has been obtained for the current environmental conditions using the derived closed form expression. The algorithm has been implemented using the Universal Serial Radio Peripheral (USRP) and GNU Radio. We have shown the efficiency of our proposal in relation to other existing methods through simulation results.
Keywords: Cognitive radio; adaptive spectrum sensing; energy detection; USRP; GNU Radio; Fuzzy Logic.
Cognitive Radio Based Solutions for Spectrum Scarcity in Palestine
by Ali Jamoos, Osama Najajri, Ahmed Abdou
Abstract: The access to telecommunication networks varies a lot from one country to another around the world. Indeed, some countries have already deployed the 4G mobile network whereas others are still with the 2G global system for mobile communication (GSM), which is the case of Palestine. The situation of the Palestinian GSM network is critical due to the following reasons: The number of channels allocated by Israeli regulation authorities to the Palestinian mobile operators is limited to 5.1% of the global bandwidth generally allocated to a country to perform GSM. In spite of the efforts of the engineers to optimize the radio planning, it is frequent that the communication links are interrupted. These interruptions are mainly due to the co-channel interference caused by the massive reuse of the allocated frequencies. Moreover, the high population density in some Palestinian cities makes this problem worse. In this paper, we study the feasibility of implementing cognitive radio (CR) secondary network either on the primary Palestinian GSM network or on the ultra-high frequency (UHF) Television (TV) band. Particularly, we propose solutions for spectrum scarcity based on the three CR paradigms, namely: interweave CR, underlay CR, and overlay CR. In the first solution, an interweave CR system is suggested to efficiently utilize the so-called TV white spaces in the UHF TV band allocated for Palestine. In the second solution, an underlay CR system based on code division multiple access (CDMA) is introduced to underlay the primary GSM system. In the third solution, an overlay CR system is proposed based on orthogonal frequency division multiplexing (OFDM) to share the same spectrum band with the primary GSM system. It is confirmed that the proposed solutions can solve the spectrum scarcity and limit the interference levels, and consequently improve system capacity.
Keywords: Spectrum scarcity; Cognitive Radio; GSM; TV white space; CDMA; OFDM.
A Two Phase Energy-Efficient Routing Protocol for Underwater Wireless Sensor Network to Enhance Data Gathering
by R. Prathiba, G. Nagarajan
Abstract: Underwater sensor network (UWSNs) characteristics such as low bandwidth, long propagation delay, limited energy, node mobility and error rate are bring many challenges in designing routing. UWSNs consist of high density sensor nodes deployed underwater to perform collaborative monitoring and resource exploration tasks over given area. The nodes in network are participates a specific task like sensing and forwarding the information to other nodes using routing protocols. Energy efficiency becomes the basic need of UWSNs in very deep water level condition and the main aim is to operate sensor with smaller battery for a longer time. In this paper, we propose an energy efficient routing protocol for UWSNs using two phase process (EERP-TP). Firstly, the balanced collective region is formed by conditional Sierpinski triangle algorithm using the node constraints, which improves the effectiveness of data gathering. Secondly, the candidate set selection is performed by chaotic multi-criteria decision (CMD) model, which computes best data forwarding node to deliver data to the destination within the required time. The simulation results show that the proposed EERP-TP method can perform very efficient than existing routing in terms of network lifetime, throughput, packet relayed rate, data loss, and energy consumption.
Keywords: two phase; collective region formation; candidate set selection; Sierpinski triangle; data gathering.
Cross-layered based Adaptive Secured Routing and Data Transmission in MANET
by JaiKumar Vinayagam, BALASWAMY CH, SOUNDARARAJAN K
Abstract: Mobile Adhoc Network (MANET) is a self organizing network consisting of a group of nodes connected to each other wirelessly. Due to the self sustaining nature of MANET, it has been used in various applications and provides good communication. However, because of certain features of MANET such as wireless medium, highly dynamic topology, limited resources, etc, the network is easily prone to various attacks which hampers the communication efficiency. The nodes are attacked mainly during the routing process and the data packets are dropped or its authenticity is compromised mostly during the data transmission process. Hence it is critical to ensure that routing and data transmission process is performed in a secure manner to ensure security of the network. In this paper, we propose to develop a Cross-layered based Adaptive Secured Routing and Data Transmission technique in MANET. Initially, the multipath routing is performed securely by encrypting every message transmission, to guarantee routing security. Then the highly secured data is transmitted through secure routes to ensure data security. Then the network is examined for intrusions. In this way, network is safeguarded from attacks and hence enhancing network operations.
Keywords: MANET; Cross-Layer; Adaptive; Routing; Data; Security.