Improving the redundancy of Knuth's balancing scheme for packet transmission systems

A simple scheme was proposed by Knuth to generate binary balanced codewords from any information word. However, this method is limited in the sense that its redundancy is twice that of the full sets of balanced codes. The gap between Knuth's algorithm's redundancy and that of the full sets of balanced codes is significantly considerable. This paper attempts to reduce that gap. Furthermore, many constructions assume that a full balancing can be performed without showing the steps. A full balancing refers to the overall balancing of the encoded information together with the prefix. We propose an efficient way to perform a full balancing scheme that does not make use of lookup tables or enumerative coding.Comment: 11 pages, 4 figures, journal article submitted to Turkish journal of electrical and computer science

Channel assembling policies for heterogeneous fifth generation (5G) cognitive radio networks.

Doctor of Philosophy in Electronic Engineering. University of KwaZulu-Natal, Durban 2016.Abstract available in PDF file

Design and Implementation of Intrusion Detection Systems using RPL and AOVD Protocols-based Wireless Sensor Networks

Wireless Sensor Network (WSN) technology has grown in importance in recent years. All WSN implementations need secure data transmission between sensor nodes and base stations. Sensor node attacks introduce new threats to the WSN. As a result, an appropriate Intrusion Detection System (IDS) is required in WSN for defending against security attacks and detecting attacks on sensor nodes. In this study, we use the Routing Protocol for Low Power and Lossy Networks (RPL) for addressing security services in WSN by identifying IDS with a network size of more or less 20 nodes and introducing 10% malicious nodes. The method described above is used on Cooja in the VMware virtual machine Workstation with the InstantContiki2.7 operating system. To track the movement of nodes, find network attacks, and spot dropped packets during IDS in WSN, an algorithm is implemented in the Network Simulator (NS2) using the Ad-hoc On-Demand Distance Vector (AODV) protocol in the Linux operating system.Keywords—Intrusion Detection Systems, wireless sensor networks, Cooja simulator, sensor nodes, NS

Integrating Two Feedback Queuing Discipline into Cognitive Radio Channel Aggregation

Queuing regime is one outstanding approach inimproving channel aggregation. If well designed and incorporatedwith carefully selected parameters, it enhances the smoothrollout of fifth/next generation wireless networks. While channelaggregation is the merging of scattered TV white space (spectrumholes) into one usable chunk for secondary users (SU). Thequeuing regime ensures that these unlicensed users (SUs) traffic/services are not interrupted permanently (blocked/dropped orforced to terminate) in the event of the licensed users (primaryuser) arrival. However, SUs are not identical in terms of trafficclass and bandwidth consumption hence, they are classified asreal time and non-real time SU respectively. Several of thesestrategies have been studied considering queuing regime with asingle feedback queuing discipline. In furtherance to previousproposed work with single feedback queuing regime, this paperproposes, develops and compares channel aggregation policieswith two feedback queuing regimes for the different classes ofSUs. The investigation aims at identifying the impacts of the twofeedbackqueuing regime on the performance of the secondarynetwork such that any SU that has not completed its ongoingservice are queued in their respective buffers. The performance isevaluated through a simulation framework. The results validatethat with a well-designed queuing regime, capacity, access andother indices are improved with significant decrease in blockingand forced termination probabilities respectively

On the Evaluation of Handover Exchange Schemes Between Two Cognitive Radio Base Stations with and without Buffers

This article investigates and evaluates a handoverexchange scheme between two secondary users (SUs) moving indifferent directions across the handover region of neighboring cellin a cognitive radio network. More specifically, this investigationcompares the performance of SUs in a cellular cognitive radionetwork with and without channel exchange scheme. The investigationshows reduced handover failure, blocking, forced andaccess probabilities respectively, for handover exchange schemewith buffer as compared to exchange scheme without buffer.It also shows transaction within two cognitive nodes within anetwork region. The system setup is evaluated through systemsimulation

On the improvement of the Knuth’s redundancy algorithm for balancing codes

Abstract: A simple scheme was proposed by Knuth to generate balanced codewords from a random binary information sequence. However, this method presents a redundancy which is twice as that of the full sets of balanced codewords, that is the minimal achievable redundancy. The gap between the Knuth’s algorithm generated redundancy and the minimal one is significantly considerable and can be reduced. This paper attempts to achieve this goal through a method based on information sequence candidates

Binary balanced codes approaching capacity

Abstract: In this paper, the construction of binary balanced codes is revisited. Binary balanced codes refer to sets of bipolar codewords where the number of “1”s in each codeword equals that of “0”s. The first algorithm for balancing codes was proposed by Knuth in 1986; however, its redundancy is almost two times larger than that of the full set of balanced codewords. We will present an efficient and simple construction with a redundancy approaching the minimal achievable one

Design and Implementation of Intrusion Detection Systems using RPL and AOVD Protocols-based Wireless Sensor Networks

Wireless Sensor Network (WSN) technology has grown in importance in recent years. All WSN implementations need secure data transmission between sensor nodes and base stations. Sensor node attacks introduce new threats to the WSN. As a result, an appropriate Intrusion Detection System (IDS) is required in WSN for defending against security attacks and detecting attacks on sensor nodes. In this study, we use the Routing Protocol for Low Power and Lossy Networks (RPL) for addressing security services in WSN by identifying IDS with a network size of more or less 20 nodes and introducing 10% malicious nodes. The method described above is used on Cooja in the VMware virtual machine Workstation with the InstantContiki2.7 operating system. To track the movement of nodes, find network attacks, and spot dropped packets during IDS in WSN, an algorithm is implemented in the Network Simulator (NS2) using the Ad-hoc On-Demand Distance Vector (AODV) protocol in the Linux operating system