The Internet of Things (IoT) technology based on intelligent sensors and physical object networks represents a prominent solution to supervise the water pipe and transmit reliable data in a power-aware way. Since the communication process is the most consuming task, we propose an IoT-based sensor node with reliable and energy-efficient abilities. The proposed Arduino-based sensor node system can detect environment parameters within the sensing range and routing data over multi-hops in a reliable and power-efficient way to nodes within its communication range. The details of the efficient and reliable routing mechanism are explained. The proposed prototype is tested in a real environment installed in the research center for validation purposes and performance evaluation.

Because of their structural and semantic inter-dependency, UML diagrams describing a software product must be consistent to ensure the success of the development process. This inter-diagram consistency is often not easy to ensure considering the multi-views the diagrams cover, the different levels of abstraction they encode, and the different development phases during which they are produced. In this paper, we tackle the consistency problem between the functional and dynamic views in behavioral diagrams of software. We propose an approach to detect and localize inter-consistency errors among UML use cases and activity diagrams. This approach is composed of two phases: measurement phase (1) and controlling phase (2). This approach is illustrated and validated through a “Restaurant management system” case study. The proposed approach will help both software designers/developers and quality assurance/testing engineers identifying and localizing the causes of software errors at early phases (specification and design).

Because of software requirements play a critical role in software development projects, measuring the non-functional requirements as well as functional requirements is therefore not to be trifled with. Software security as a non-functional requirement is one of the most important quality characteristic that is recently added in the ISO 25010 quality models (previously defined as sub characteristics in ISO 9126). This characteristic must be evaluated cautiously and precisely during all the software life-cycle and especially early in the design phase. The purpose of this paper is early evaluating security in web application. To achieve this purpose, we propose to measure the quality attributes of authenticity through a combination of functional and structural size of the authenticity sequence diagram at the design phase. This combination of measurement can be used to identify the risk of violation of authenticity in web application design. An example of GeoNetwork web application is used to illustrate our proposed measurement for evaluating security as defined by ISO/IEC 25010.

Energy saving strategies pose challenges for wireless Sensor Networks communication, as the nodes have limited energy resources and are battery powered. Thus, there is a strong interest in developing energy efficient transmission techniques. In this paper, we present a new approach to minimize the energy consumption of clustered wireless sensor networks, while achieving the required level of reliability. We consider clusters where sensors transmit monitored data to nearby cluster-head using cooperative communication. The goal of our approach is to minimize the transmit power energy based on Bit Error Probability (BEP) criterion for selective digital relaying (SDR) schemes whose closed form expression was recently derived in previous works. Therefore, the proposed scheme can efficiently allocate the least transmission power among the source and the relays that satisfy the predefined level of reliability while decreasing the energy consumption of the node. Simulation results show that our relay selection algorithm achieves significant energy savings (more than 50% compared with direct transmissions for moderate SNR values and up to 90% in high SNR regions).

In this paper, we propose a dynamic spectrum sharing protocol where a pair of secondary users and a pair of primary users bidirectionally communicate. A secondary relay equipped with multiple antennas is deployed to assist the secondary transmissions and improve the secondary access to the spectrum. We employ a new time division access so that no interference may exist between primary and secondary users. The proposed scheme is then compared to the axiomatic and simple scheme where the secondary users communicate with each other with the assistance of the relay in underlay mode. We study and compare the performances of the two schemes in terms of outage probability. An upper bound for the secondary outage probability of the proposed scheme is derived. Our simulation results prove that the proposed scheme significantly outperforms the underlay spectrum sharing while in both schemes, the primary outage probability is kept identical to the case where secondary users are absent.

In this paper, we propose a spectrum sharing protocol where a pair of secondary users and a pair of primary users bidirectionally communicate. A secondary relay equipped with two antennas is deployed to ensure two-way relaying for primary users and thus they give the chance for secondary users to access the spectrum. To transmit its data, the secondary transmitter does not take into account the interference caused to primary receiver. It adjusts its transmit power so that the secondary required data rate is attained. In return, the relay uses zero forcing precoding to make two way relaying for primary users with no interference. We analytically derive the average outage probability and bit error probability of secondary transmissions. Analytical results are verified through simulations. Our proposed spectrum sharing scheme is proved to significantly outperform the conventional underlay scheme while respecting the performances requirement of the primary users.

In this paper, we compare the performance in terms of symbol error probability, data rate and power consumption of the use of fixed transmit power (FTP) and adaptive transmit power (ATP) in underlay cognitive radio networks. The use of FTP alleviates the signaling requirements of underlay cognitive radio networks compared to the ATP. Nevertheless, the use of FTP influences the performances of the underlay cognitive radio networks. To study this influence, we consider three relay selection schemes using FTP: opportunistic decode and forward with FTP (O-DF with FTP), opportunistic amplify and forward with FTP (O-AF with FTP) and partial relay selection with FTP (PR with FTP). We compare the performances of these schemes in terms of symbol error probability, data rate and power consumption with three relay selection schemes using ATP: opportunistic decode and forward with ATP (O-DF with ATP), opportunistic amplify and forward with ATP (O-AF with ATP) and partial relay selection with ATP (PR with ATP). We provide exact and/or lower bound expressions of the symbol error probabilities of O-DF, O-AF and PR with FTP. The analytical study for the data rate and the power consumption is also provided. Our comparison study shows that FTP has a positive impact on the data rate and power consumption performance while it deteriorates the symbol error probability performance.

In this paper, we consider a secondary broadcast network where a multi-antenna transmitter broadcasts the same data toward a large number of secondary receivers (SRs) in the presence of a primary communication. Thanks to its multi-antenna capabilities, the secondary transmitter (ST) uses an orthogonal beamforming technique to broadcast its data while controlling the interference perceived by the primary receiver. We develop and investigate three broadcast transmission schemes. The first one is simple and operates in underlay mode where the ST broadcasts its data simultaneously as the primary transmission. The second scheme operates in overlay mode where ST helps the primary transmission by means of cooperative diversity transmission. SRs exploit a post-transmission interference cancellation techniques to cancel the interference caused by the primary transmission. The third scheme operates also in overlay mode and the secondary network exploits also the cooperative diversity technique. The metric used to evaluate the performance of secondary broadcast network is the rate of served SRs. We compare the performances of the three schemes by simulations. Also, analytical expressions of the outage probability for the first and second schemes are provided. Simulations along with analytical results proved that our two overlay proposed schemes ensure low secondary outage probability.

Achieving the goal of reliably delivering data to all nodes in broadcast wireless networks is very challenging since wireless channels may experience severe variations in signal strength and channel impairments. To mitigate this problem, one or several relays can be used as collaborators to forward the broadcasted signal to other nodes. In this paper, we propose and investigate several single relay selection schemes in broadcast wireless networks using either selective digital relaying or selective analog relaying. The key idea is to classify the nodes in the considered broadcast network into two sets. A set of "reliable" nodes, whose source-node signal-to-noise ratio exceeds a threshold value and a set of "unreliable" nodes gathering the remaining ones. Then, one node among "reliable" nodes is activated as a relay. We derive closed form expressions of the end-to-end bit error probabilities of some proposed single relay selection schemes for selective digital relaying. The data rate loss due to the cooperation is also studied. Analytical results along with simulations prove that compared to the direct transmission, the single relay selection schemes improve significantly the bit error probability performance of the broadcast network.

In this paper, we derive exact form expressions for the Bit Error Probability (BEP) and throughput of cooperative Direct Sequence-Code Division Multiple Access (DS-CDMA) systems using incremental selective relaying which combines selective relaying with incremental relaying protocols in the presence of multipath propagation. The derived results are valid for any multipath intensity profile of the channel and any path delays. They also consider the correlation of the multipath gains. Simulation results along with analytical studies of BEP and throughput prove that the combination of incremental relaying with selective relaying in cooperative DS-CDMA systems improve significantly the throughput performance and can achieve the maximum possible spatial diversity when it is required by destination.

In this paper, we derive the end-to-end (e2e) Bit Error Probability (BEP) of cooperative Multi Carrier Code Division Multiple Access (MC-CDMA) systems using selective threshold digital relaying (STDR). In STDR, a set of potential relays whose received Signal-to-Noise Ratio (SNR) exceeds a threshold value γt, called reliable relays, is formed. Then, only the best relay among reliable relays is allowed to retransmit the received signal. We activate the relay with the largest SNR in relay-destination link. The derived BEP results are valid for any multipath intensity profile of the channel.