Showing papers in "Telecommunication Systems in 2018"

Security in Internet of Things: issues, challenges, taxonomy, and architecture

Abstract: Internet technology is very pervasive today. The number of devices connected to the Internet, those with a digital identity, is increasing day by day. With the developments in the technology, Internet of Things (IoT) become important part of human life. However, it is not well defined and secure. Now, various security issues are considered as major problem for a full-fledged IoT environment. There exists a lot of security challenges with the proposed architectures and the technologies which make the backbone of the Internet of Things. Some efficient and promising security mechanisms have been developed to secure the IoT environment, however, there is a lot to do. The challenges are ever increasing and the solutions have to be ever improving. Therefore, aim of this paper is to discuss the history, background, statistics of IoT and security based analysis of IoT architecture. In addition, we will provide taxonomy of security challenges in IoT environment and taxonomy of various defense mechanisms. We conclude our paper discussing various research challenges that still exist in the literature, which provides better understanding of the problem, current solution space, and future research directions to defend IoT against different attacks.

Defending against phishing attacks: taxonomy of methods, current issues and future directions

Abstract: Internet technology is so pervasive today, for example, from online social networking to online banking, it has made people's lives more comfortable. Due the growth of Internet technology, security threats to systems and networks are relentlessly inventive. One such a serious threat is "phishing", in which, attackers attempt to steal the user's credentials using fake emails or websites or both. It is true that both industry and academia are working hard to develop solutions to combat against phishing threats. It is therefore very important that organisations to pay attention to end-user awareness in phishing threat prevention. Therefore, aim of our paper is twofold. First, we will discuss the history of phishing attacks and the attackers' motivation in details. Then, we will provide taxonomy of various types of phishing attacks. Second, we will provide taxonomy of various solutions proposed in literature to protect users from phishing based on the attacks identified in our taxonomy. Moreover, we have also discussed impact of phishing attacks in Internet of Things (IoTs). We conclude our paper discussing various issues and challenges that still exist in the literature, which are important to fight against with phishing threats.

Towards detection of phishing websites on client-side using machine learning based approach

Abstract: The existing anti-phishing approaches use the blacklist methods or features based machine learning techniques. Blacklist methods fail to detect new phishing attacks and produce high false positive rate. Moreover, existing machine learning based methods extract features from the third party, search engine, etc. Therefore, they are complicated, slow in nature, and not fit for the real-time environment. To solve this problem, this paper presents a machine learning based novel anti-phishing approach that extracts the features from client side only. We have examined the various attributes of the phishing and legitimate websites in depth and identified nineteen outstanding features to distinguish phishing websites from legitimate ones. These nineteen features are extracted from the URL and source code of the website and do not depend on any third party, which makes the proposed approach fast, reliable, and intelligent. Compared to other methods, the proposed approach has relatively high accuracy in detection of phishing websites as it achieved 99.39% true positive rate and 99.09% of overall detection accuracy.

A survey on communication components for IoT-based technologies in smart homes

Abstract: The new and disruptive Internet of Things (IoT)-based technologies being used in smart homes have significantly bounded and dispersed communication components. To examine these technologies and provide researchers with a clear vision toward this area, we must be aware of the utilized approaches and the existing limitations in this line of research. To this end, an extensive search was conducted for articles dealing with (a) smart homes, (b) IoT, and (c) related applications were comprehensively reviewed and a coherent taxonomy for these articles was established. ScienceDirect, IEEE Xplore, and Web of Science databases were checked for articles on IoT-based smart home technologies. The retrieved articles were then filtered based on specified criteria “Communication components aspects”, and 82 articles were eventually selected and classified into four categories. The first category included articles that representing internet devices in a framework or model that follows the requirements of the stage in which any system is developed, the second category included analytical studies that monitor the possible changes in the variables used in a specific case study, the third category included evaluation, comparative studies, and assessing their worth or merit, and the fourth category included reviews and surveys a review and survey of the communication components of IoT-based smart home technologies. The motivation for using IoT-based technologies in smart homes, the issues related to application obstruction, and the development and utilization of smart homes are then examined based on the findings from the literature. With the exception of the 82 articles reviewed earlier, the telecommunication standards and concepts of this research were covering IoT solutions, communication protocols, IoT stack protocol, and quality of service for IoT based smart home technologies.

Improved DV-Hop localization algorithm using teaching learning based optimization for wireless sensor networks

Abstract: Node localization is one of the most critical issues for wireless sensor networks, as many applications depend on the precise location of the sensor nodes. To attain precise location of nodes, an improved distance vector hop (IDV-Hop) algorithm using teaching learning based optimization (TLBO) has been proposed in this paper. In the proposed algorithm, hop sizes of the anchor nodes are modified by adding correction factor. The concept of collinearity is introduced to reduce location errors caused by anchor nodes which are collinear. For better positioning coverage, up-gradation of target nodes to assistant anchor nodes has been used in such a way that those target nodes are upgraded to assistant anchor nodes which have been localized in the first round of localization. For further improvement in localization accuracy, location of target nodes has been formulated as optimization problem and an efficient parameter free optimization technique viz. TLBO has been used. Simulation results show that the proposed algorithm is overall 47, 30 and 22% more accurate than DV-Hop, DV-Hop based on genetic algorithm (GADV-Hop) and IDV-Hop using particle swarm optimization algorithms respectively and achieves high positioning coverage with fast convergence.

An energy-aware routing protocol for wireless sensor network based on genetic algorithm

Abstract: Energy saving and effective utilization are an essential issue for wireless sensor network. Most previous cluster based routing protocols only care the relationship of cluster heads and sensor nodes but ignore the huge difference costs between them. In this paper, we present a routing protocol based on genetic algorithm for a middle layer oriented network in which the network consists of several stations that are responsible for receiving data and forwarding the data to the sink. The amount of stations should be not too many and not too few. Both cases will cause either too much construction cost or extra transmission energy consumption. We implement five methods to compare the performance and test the stability of our presented methods. Experimental results demonstrate that our proposed scheme reduces the amount of stations by 36.8 and 20% compared with FF and HL in 100-node network. Furthermore, three methods are introduced to improve our proposed scheme for effective cope with the expansion of network scale problem.

Challenges and research directions for Internet of Things

Abstract: The emergence of Internet of Things (IoT) is empowered by the availability of the high volume of smart sensors, Radio Frequency Identification, a suitable communication technologies and protocols. In the near future, the Internet will be full of heterogeneous connected devices. In recent years, the IoT has drawn significant attention as it can solve difficult problems. However, the heterogeneity of devices and the large scale networks expose the IoT to many challenges that must be addressed; otherwise, the systems performance will deteriorate. As an attempt to identify these challenges, this paper comprehensibly cites the main IoT concepts, the serious IoT challenges and the quality of services presented in the recent literature. It also investigates the corresponding main research directions and the proposed solutions. This paper can increase the knowledge of the reader since it is the first IoT survey that presents load balancing algorithms utilized in solving the extreme data storage challenge.

Technique for order performance by similarity to ideal solution for solving complex situations in multi-criteria optimization of the tracking channels of GPS baseband telecommunication receivers

Abstract: Global positioning system (GPS) has undergone intensive development, starting as an advanced specialized tool to a general-purpose gadget used in our daily lives. GPS exists in new technologies, applications, and consumer products, especially in smartphones and tablets. In a GPS receiver design, power consumption and localization accuracy are critical factors that affect the outcome of a GPS receiver system. Theoretically, increasing the number of required tracking channels in a GPS baseband receiver increases the design complexity and size of this system. Thus, power consumption can significantly increase. The receiver should acquire and track numerous satellites to improve the location accuracy of a position, thereby indicating that the receiver requires a high number of tracking channels. Thus, optimizing these tracking channels to balance the conflict among performance parameters is a difficult and challenging task. This paper presents a technique for order performance by similarity to ideal solution (TOPSIS) for solving complex situations for multi-criteria optimization of the tracking channels of GPS baseband telecommunication receiver. Nine operation modes of GPS receiver were evaluated by each design parameter, such as power consumption, localization accuracy, and time with no position available for static and dynamic positioning. Then, the TOPSIS was utilized and implemented to measure and rank the overall performance of tracking channel selection. Results of this study indicate that (1) multi-objective optimization is a reliable strategy for visualizing the trade-off among the GPS design parameters and providing a dynamic power consumption planning. (2) The best aggregated performance of the GPS receiver occurs when the number of tracking channels equals five and six for static and dynamic positioning, respectively. (3) The most frequent number of available satellites is eight, whereas the other number of satellites is a rare case to acquire. However, GPS standards require that available GPS satellites are constantly 12 at any time and place.

CDMA-based anti-collision algorithm for EPC global C1 Gen2 systems

Abstract: Frame slotted ALOHA protocol as a key technology to improve system throughput has been widely applied to modern radio frequency identification systems. In this paper, a novel frame slotted ALOHA collision arbitration protocol based on code division multiple access has been proposed. The main aim of the proposed algorithm is to avoid collisions between multiple tags. In the scheme, an orthogonal sequence is used as the means to distinguish the transmitted data from different tags within the same time slot and frequency band. The theoretical analysis and simulation results proved that the performance of our proposed algorithm outperforms the existing ALOHA-based protocols.

Secure and efficient anonymous authentication scheme for three-tier mobile healthcare systems with wearable sensors

Abstract: The mobility and openness of wireless communication technologies make Mobile Healthcare Systems (mHealth) potentially exposed to a number of potential attacks, which significantly undermines their utility and impedes their widespread deployment. Attackers and criminals, even without knowing the context of the transmitted data, with simple eavesdropping on the wireless links, may benefit a lot from linking activities to the identities of patient’s sensors and medical staff members. These vulnerabilities apply to all tiers of the mHealth system. A new anonymous mutual authentication scheme for three-tier mobile healthcare systems with wearable sensors is proposed in this paper. Our scheme consists of three protocols: Protocol-1 allows the anonymous authentication nodes (mobile users and controller nodes) and the HSP medical server in the third tier, while Protocol-2 realizes the anonymous authentication between mobile users and controller nodes in the second tier, and Protocol-3 achieves the anonymous authentication between controller nodes and the wearable body sensors in the first tier. In the design of our protocols, the variation in the resource constraints of the different nodes in the mHealth system are taken into consideration so that our protocols make a better trade-off among security, efficiency and practicality. The security of our protocols are analyzed through rigorous formal proofs using BAN logic tool and informal discussions of security features, possible attacks and countermeasures. Besides, the efficiency of our protocols are concretely evaluated and compared with related schemes. The comparisons show that our scheme outperforms the previous schemes and provides more complete and integrated anonymous authentication services. Finally, the security of our protocols are evaluated by using the Automated Validation of Internet Security Protocols and Applications and the SPAN animator software. The simulation results show that our scheme is secure and satisfy all the specified privacy and authentication goals.

An energy optimization in wireless sensor networks by using genetic algorithm

Abstract: Wireless sensor networks (WSNs) are used for several commercial and military applications, by collecting, processing and distributing a wide range of data. Maximizing the battery life of WSNs is crucial in improving the performance of WSN. In the present study, different variations of genetic algorithm (GA) method have been implemented independently on energy models for data communication of WSNs with the objective to find out the optimal energy $$\hbox {(E)}$$(E) consumption conditions. Each of the GA methods results in an optimal set of parameters for minimum energy consumption in WSN related to the type of selected energy model for data communication, while the best performance of the GA method [energy consumption $$(\hbox {E}=3.49\times 10^{-4}\,\hbox {J})$$(E=3.49×10-4J)] is obtained in WSN for communication distance (d) $${\ge }87\,\hbox {m}$$?87m in between the sensor cluster head and a base station.

ESOT: a new privacy model for preserving location privacy in Internet of Things

Abstract: The Internet of Things (IoT) means connecting everything with every other thing through the Internet. In IoT, millions of devices communicate to exchange data and information with each other. During communication, security and privacy issues arise which need to be addressed. To protect information about users’ location, an efficient technique should be devised. Several techniques have already been proposed for preserving location privacy in IoT. However, the existing research lags in preserving location privacy in IoT and has highlighted several issues such as being specific or being restricted to a certain location. In this paper, we propose a new location privacy technique called the enhanced semantic obfuscation technique (ESOT) to preserve the location information of a user. Experimental results show that ESOT achieves improved location privacy and service utility when compared with a well-known existing approach, the semantic obfuscation technique.

Computational intelligence based localization of moving target nodes using single anchor node in wireless sensor networks

Abstract: Wireless Sensor Networks (WSNs) have tremendous ability to interact and collect data from the physical world. The main challenges for WSNs regarding performance are data computation, prolong lifetime, routing, task scheduling, security, deployment and localization. In recent years, many Computational Intelligence (CI) based solutions for above mentioned challenges have been proposed to accomplish the desired level of performance in WSNs. Application of CI provides independent and robust solutions to ascertain accurate node position (2D/3D) with minimum hardware requirement (position finding device, i.e., GPS enabled device). The localization of static target nodes can be determined more accurately. However, in the case of moving target nodes, accurate position of each node in network is a challenging problem. In this paper, a novel concept of projecting virtual anchor nodes for localizing the moving target node is proposed using applications of Particle Swarm Intelligence, H-Best Particle Swarm Optimization, Biogeography Based Optimization and Firefly Algorithm separately. The proposed algorithms are implemented for range-based, distributed, non-collaborative and isotropic WSNs. Only single anchor node is used as a reference node to localize the moving target node in the network. Once a moving target node comes under the range of a anchor node, six virtual anchor nodes with same range are projected in a circle around the anchor node and two virtual anchor nodes (minimum three anchor nodes are required for 2D position) in surrounding (anchor and respective moving target node) are selected to find the 2D position. The performance based results on experimental mobile sensor network data demonstrate the effectiveness of the proposed algorithms by comparing the performance in terms of the number of nodes localized, localization accuracy and scalability. In proposed algorithms, problem of Line of Sight is minimized due to projection of virtual anchor nodes.

An unequal cluster-based routing scheme for multi-level heterogeneous wireless sensor networks

Abstract: In wireless sensor networks (WSNs), clustering can significantly reduce energy dissipation of nodes, and also increase communication load of cluster heads. When multi-hop communication model is adopted in clustering, “energy hole” problem may occur due to unbalanced energy consumption among cluster heads. Recently, many multi-hop clustering protocols have been proposed to solve this problem. And the main way is using unequal clustering to control the size of clusters. However, many of these protocols are about homogeneous networks and few are about heterogeneous networks. In this paper, we present an unequal cluster-based routing scheme for WSNs with multi-level energy heterogeneity called UCR-H. The sensor field is partitioned into a number of equal-size rectangular units. We first calculate the number of clusters in each unit by balancing energy consumption among the cluster heads in different units. And then we find the optimal number of units by minimizing the total energy consumption of inter-cluster forwarding. Finally, the size of clusters in each unit is elaborately designed based on node’s energy level and the number of clusters in this unit. And a threshold is also designed to avoid excessive punishment to the nodes with higher energy level. Simulation results show that our scheme effectively mitigates the “energy hole” problem and achieves an obvious improvement on the network lifetime.

Hardware implementation of fault tolerance NoC core mapping

Abstract: Due to performance and reliability, network on chip (NoC) is considered to be the future generation interconnect technique for multiple cores in a chip. This paper proposes a system level core mapping technique which improves the performance of the whole system, while rectifying the temporary faults and permanent faults in the system using error correcting codes and spare core. This technique mainly focuses on the core mapping and faults on the system. This results in reliable core mapping and improved performance when a fault-related error occurs on an NoC. At last, the proposed core mapping technique is simulated and verified on FPGA board (Kintex-7 FPGA KC705 Evaluation Kit).

Fuzzy logic based 3D localization in wireless sensor networks using invasive weed and bacterial foraging optimization

Abstract: The purpose of this paper is to improve the performance of node localization in 3D space for wireless sensor network. To achieve this objective, we propose two range free localization algorithms for 3D space in anisotropic environment using the application of bacterial foraging optimization (BFO) and invasive weed optimization (IWO). In proposed methods, only received signal strength (RSS) information between nodes is sufficient for estimating target nodes locations. The RSS information gives clue to find out the distances between target nodes and anchor nodes. To overcome the non-linearity between RSS and distance, edge weights between target nodes and their neighbouring anchor nodes are considered to estimate the positions of target nodes. To further reduce the computational complexity and to model the edge weights, we use fuzzy logic system in this paper. BFO and IWO techniques are used to further optimize the edge weights separately to achieve the better localization accuracy. The simulation results show the superiority of the proposed algorithms as compared to centroid method, weighted centroid and existing 3D localization algorithms in terms of localization accuracy, stability, positioning coverage and scalability.

A stateless fairness-driven active queue management scheme for efficient and fair bandwidth allocation in congested Internet routers

Abstract: Fair bandwidth sharing is important for the Internet architecture to be more accommodative of the heterogeneity. The Internet relies primarily on the end-systems to cooperatively deploy congestion control mechanisms for achieving high network utilization and some degree of fairness among flows. However, the cooperative behavior may be abandoned by some end-systems that act selfishly to be more competitive through bandwidth abuse. The result can be severe unfairness and even congestion collapse. Fairness-driven active queue management, thus, becomes essential for allocating the shared bottleneck bandwidth fairly among competing flows. This paper proposes a novel stateless active queue management algorithm, termed CHOKeH, to enforce fairness in bottleneck routers. CHOKeH splits the queue into dynamic regions at each packet arrival and treats each region differently for performing matched-drops using a dynamically updated drawing factor, which is based on the level of queue occupancy and the buffer size. In this way, CHOKeH can effectively identify and restrict unfair flows from dominating the bandwidth by discarding more packets from these flows. The performance of CHOKeH is studied through extensive simulations. The results demonstrate that CHOKeH is well suited for fair bandwidth allocation even in the presence of multiple unresponsive flows and across a wider range of buffer sizes. The results also show the ability of CHOKeH to provide inter-protocol and intra-protocols fairness and protection for short-lived flows. With a low per-packet-processing complexity, CHOKeH is amenable to implementation in core routers to offer an effective incentive structure for end-systems to self-impose some form of congestion control.

Perspectives for resource sharing in 5G networks

Abstract: The era of 5G networks is approaching fast and its commercialization is planned for 2020. However, there are still numerous aspects that need to be solved and standardized before an average end-user can benefit from them on a daily basis. The 5G technology is supposed to be faster, provide services of higher quality, and better address the evolving needs of customers. As a consequence, 5th generation network needs to be implemented with efficiency and flexibility in mind, and thus, it fits well with the concepts of virtualization which enable sharing of physical resources among different operators, services, and applications. In this paper, we present an overview of these concepts, resulting from our discussions, i.e. between academic researchers and active network architects, and we describe the operation of a model that is most likely to emerge in such a complex network environment.

Physarum-inspired routing protocol for energy harvesting wireless sensor networks

Abstract: In order to resolve the traditional limited lifetime problem, energy harvesting technology has been introduced into wireless sensor network (WSN) in recent years, engendering a new kind of network which is called energy harvesting wireless sensor network (EHWSN). In EHWSNs, besides the traditional issues, such as energy consumption, energy equilibrium, transmission efficiency, etc., there are still new challenges, such as how to utilize harvested energy efficiently and how to make more sensor nodes so as to achieve unlimited lifetime under actual situation. In this paper, inspired by slime mold Physarum polycephalum, a novel bionic routing protocol, abbreviated as EHPRP, is proposed for EHWSNs to address above problems without predicting harvestable energy value. Three distributed routing algorithms with low algorithm complexity are proposed which would prominently reduce the processing delay and conserve energy. Furthermore, the mathematic theoretical analysis is made to prove the stability of EHPRP routing strategy. Finally, simulation results present that, compared with other typical algorithms, EHPRP consumes less energy, always making the whole network obtain an unlimited lifetime, and displaying more uniform network energy distribution under different workload conditions.

A queueing model of an energy harvesting sensor node with data buffering

Abstract: Battery lifetime is a key impediment to long-lasting low power sensor nodes and networks thereof Energy harvesting—conversion of ambient energy into electrical energy—has emerged as a viable alternative to battery power Indeed, the harvested energy mitigates the dependency on battery power and can be used to transmit data However, unfair data delivery delay and energy expenditure among sensors remain important issues for such networks We study performance of sensor networks with mobile sinks: a mobile sink moves towards the transmission range of the different static sensor nodes to collect their data We propose and analyse a Markovian queueing system to study the impact of uncertainty in energy harvesting, energy expenditure, data acquisition and data transmission In particular, the energy harvesting sensor node is described by a system with two queues, one queue corresponding to the battery and the other to the data buffer We illustrate our approach by numerical examples which show that energy harvesting correlation considerably affects performance measures like the mean data delay and the effective data collection rate

An adaptive LTE listen-before-talk scheme towards a fair coexistence with Wi-Fi in unlicensed spectrum

Abstract: The technological growth combined with the exponential increase of wireless traffic are pushing the wireless community to investigate solutions to maximally exploit the available spectrum. Among the proposed solutions, the operation of Long Term Evolution (LTE) in the unlicensed spectrum (LTE-U) has attracted significant attention. Recently, the 3rd Generation Partnership Project announced specifications that allow LTE to transmit in the unlicensed spectrum using a Listen Before Talk (LBT) procedure, respecting this way the regulator requirements worldwide. However, the proposed standards may cause coexistence issues between LTE and legacy Wi-Fi networks. In this article, it is discussed that a fair coexistence mechanism is needed to guarantee equal channel access opportunities for the co-located networks in a technology-agnostic way, taking into account potential traffic requirements. In order to enable harmonious coexistence and fair spectrum sharing among LTE-U and Wi-Fi, an adaptive LTE-U LBT scheme is presented. This scheme uses a variable LTE transmission opportunity (TXOP) followed by a variable muting period. This way, co-located Wi-Fi networks can exploit the muting period to gain access to the wireless medium. The scheme is studied and evaluated in different compelling scenarios using a simulation platform. The results show that by configuring the LTE-U with the appropriate TXOP and muting period values, the proposed scheme can significantly improve the coexistence among LTE-U and Wi-Fi in a fair manner. Finally, a preliminary algorithm is proposed on how the optimal configuration parameters can be selected towards harmonious and fair coexistence.

Analysis of K-tier 5G heterogeneous cellular network with dual-connectivity and uplink–downlink decoupled access

Abstract: Smallcells deployment in heterogeneous networks (HetNets) introduce uplink (UL) downlink (DL) asymmetry, backhaul bottleneck, cell load imbalances, increased core network signaling, interference and mobility management problems. In order to address these issues, concept of dual connectivity has been introduced in 3rd generation partnership project (3GPP) release 12. In dual connectivity, a given user equipment can consume radio resources of at least two different network points connected through non-ideal backhaul for spectrum aggregation and cooperative access mechanisms in dense 5G HetNets. Alternatively, another concept of downlink and uplink decoupling (DUDe) has also been recently introduced in 3GPP to improve uplink performance, load balancing and cell capacity. In order to take advantage of the strengths of these latest developments, this paper significantly advances prior work by analyzing K-tier 5G HetNets having dual connectivity and decoupled access (joint DUDe dual-connectivity) for spectrum aggregation in UL and DL. In the preceding works, K-tiers as per present-day heterogeneity, uplink power control and receiver noise have not been considered for joint DUDe dual-connectivity. With the use of stochastic geometry, we have developed closed form solutions for association, coverage and outage probabilities along with average throughput for joint DUDe dual-connectivity by considering uplink power control, receiver noise and K-tiers of HetNets. The resultant performance metrics are evaluated in terms of achieved gains over conventional downlink received power access policies. Results show that cell association technique based on joint DUDe dual-connectivity can significantly improve load balancing, mobility management and UL performance for forthcoming 5G HetNets.

Speech authentication and content recovery scheme for security communication and storage

Abstract: With the rapid development of Internet, it brings a lot of conveniences. However, the data transmission and storage are faced with some security issues that seem to be obstacles to overcome, such as privacy protection and integrity authentication. In this paper, an efficient speech watermarking algorithm is proposed for content authentication and recovery in encrypted domain. The proposed system consists of speech encryption, watermark generation and embedding, content authentication and recovery. In the encryption process, chaotic and block cipher are combined to eliminate the positional correlation and conceal the statistical feature. In the watermark embedding process, approximation coefficients of integer wavelet transform are used to generate watermark and the detail coefficients are reserved to carry watermark. Theoretical analysis and simulation results show that the proposed scheme has high security and excellent inaudibility. Compared with previous works, the proposed scheme has strong ability to detect de-synchronization attacks and locate the corresponding tampered area without using synchronization codes. Meanwhile, the selective encryption will not influence the selective watermarking operation. Similarly, the operation of watermarking will not affect the decryption of the encrypted speech. Additionally, the tampered samples can be recovered without any auxiliary watermark information.

Joint mode selection and resource allocation in D2D communication based underlaying cellular networks

Abstract: Device-to-Device (D2D) communication technology, under the standardization of third generation partnership project and a component of the evolving fifth generation architecture, is mainly aimed to increase system capacity and data rate via providing direct communications between end devices without the use of routing data through the network. Apart from the attracting features, due to the resource sharing between cellular user equipment (CUE) and D2D user equipment (DUE) in such communications, an efficient algorithm for resource and power allocation to DUE, especially for mobile users is necessary to maintain the performance. The current paper introduces a joint mode algorithm for mobile user to choose between cellular and D2D communications and thereby, analyzes resource allocation issues. We propose an efficient algorithm for mobility management of users based on their current connection modes. The locations of D2D pairs are estimated by Levenberg–Marquardt method based on the received signal strength (RSS) from different macrocells. Since the range of D2D communication is much shorter than that of cellular communication, in order to prevent ping-pong handoffs between cellular and D2D modes, we propose the estimation of the next RSS samples in cellular mode prior to switching to D2D mode. In both cellular and D2D modes, the allocated resource block (RB) is the one with the highest signal to interference plus noise ratio (SINR) in order to increase the throughput, under the condition of providing minimum SINR requirement of CUE. This is achieved via transmission power control of the D2D pair. For performance evaluation, we studied the effects of increasing velocity of D2D and cellular users, number of users, and SINR threshold. The results indicate that the proposed solution fairly manages the communication mode of mobile users and incurs improvement in system throughput.

Energy harvesting assisted cognitive radio: random location-based transceivers scheme and performance analysis

Abstract: We consider spectrum-sharing scenario where coexist two communication networks including primary network and secondary network using the same spectrum. While the primary network includes directional multi-transceivers, the secondary network consists of relaying-based transceiver forwarding signals by energy harvesting assisted relay node. In cognitive radio, signals transmitted from secondary network are sufficiently small so that all of primary network receivers have signal to noise ratio (SNR) greater than a given threshold. In contrast, the transmitted signals from primary network cause increasing noise which is difficult to demodulate at secondary network nodes and hence it leads to the peak power constraint. In this paper, we focus on the influence of random location of transceivers at primary network using decode-and-forward protocol. Specifically, we derive closed-form outage probability expression of the secondary network under random location of transceivers and peak power constraint of primary network. This investigation shows the relationship between the fraction of energy harvesting time $$\alpha $$ of time switching-based relaying protocol on outage probability of secondary network and throughput. In addition, we analyse the influence of the number of primary network transceivers as well as primary network’s SNR threshold on secondary network. Furthermore, the trade-off between increasing energy harvesting and rate was investigated under the effect of energy conversion efficiency. The accuracy of the expressions is validated via Monte-Carlo simulations. Numerical results highlight the trade-offs associated with the various energy harvesting time allocations as a function of outage performance.

Neighbors’ interference situation-aware power control scheme for dense 5G mobile communication system

Abstract: The next generation mobile communication (5G) systems is targeting very high data rate by deploying more number of small cells, but this deployment results in high cross-tier interference because of using the same frequency band. To solve this challenge, an efficient power control scheme is desired specially for the case of uplink scenario. Thus, to solve this challenge, we propose the neighbors’ interference situation-aware uplink power control (IA-ULPC) scheme to reduce the cross-tier interference. In this scheme, we consider the interference situation of the neighbor cells while controlling the power of the users. Moreover, we also derive the target signal-to-interference and noise-ratio ( $$P_0$$ ) equation to dynamically adjust it based on the neighbors’ base station interference situation. We compare the performance of the proposed IA-ULPC with the conventional fractional power control scheme (C-FPC). The extensive system-level simulations are carried out to prove the validity of the proposed IA-ULPC scheme which almost doubles the user average throughput and also decreases the interference around 20% in dense two-tier heterogeneous network environment as compared to C-FPC.

Joint power allocation and relay selection strategy for 5G network: a step towards green communication

Abstract: Green communication has emerged as the most important concept for the next generation networks. Along with improved data rate and capacity, the upcoming 5G networks aim at improving energy efficiency without compromising on the user experience. In this paper, we have used amplify and forward relays in the heterogeneous network topology consisting of low power and high power nodes. A three layered system model for power optimization is discussed using a relay selection strategy for power optimization with the aim to improve energy efficiency of the network. Further, we have used Hidden Markov Model for training and maintaining of base station, relay and SCA with the aim of probabilistic power allocation to client nodes in order to solve the power optimization problem. We have also used adaptive modulation schemes for lowering the power consumption of the network to meet our goal of green communication for the next generation network.

A genetic algorithm approach for multi-attribute vertical handover decision making in wireless networks

Abstract: Mobile terminals can typically connect to multiple wireless networks which offer varying levels of suitability for different classes of service Due to the changing dynamics of network attributes and mobile users’ traffic needs, vertical handovers across heterogeneous networks become highly desirable Multiple attribute decision making (MADM) techniques offer an efficient approach for ranking competing networks and selecting the best one according to specific quality of service parameters In this paper, a genetic algorithm (GA) is applied to optimize network attributes’ weighting by emphasizing ranking differences among candidate networks, thereby aiding correct decision making by reducing unnecessary handovers and ranking abnormalities The performance of the proposed GA-based vertical handover is investigated with typical MADM techniques including Simple Additive Weighting (SAW) and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) The results show that the proposed GA-based weight determination approach reduces the abnormality observed in the conventional SAW and TOPSIS techniques substantially The results of this paper will help ensuring the application of MADM methods to more dynamic and challenging decision making problems encountered in wireless network

Remove key escrow from the BF and Gentry identity-based encryption with non-interactive key generation

Abstract: Key escrow is inherent in identity based encryption (IBE) since it was first put forward by Shamir. A key generation center (KGC) or private key generator is in charge of generating the user’s secret key, therefore a malicious one can decrypt any ciphertext without being found. This paper introduces a new scheme to eliminate key escrow from IBE. This scheme is based on the security concept of anonymous ciphertext indistinguishability against key generation center (ACI-KGC) which is introduced by Chow. We equip the Boneh and Franklin IBE (BF-IBE) and Gentry-IBE with our scheme and give the security analysis to show the accuracy and the security of it. In contrast to Chow’s scheme, to generate the secret key, our approach does not require the interactive protocol which brings about much extra costs.

A routing scheme for connecting delay-sensitive urban vehicular networks to the IPv6-based internet

Abstract: This paper proposes a routing scheme for connecting urban vehicular networks to the IPv6-based internet. In this scheme, the architecture based on vehicular domains is proposed to reduce the routing delay and packet loss. Based on this architecture, the intra-VD and inter-VD routing algorithms are proposed. In the intra-VD routing algorithm, a vehicle achieves the communications with the IPv6-based internet via the nearest access point, so the routing delay and packet loss are lowered. When a vehicle moves within one vehicular domain, its care-of address keeps unchanged. As a result, the extra routing delay and packet loss caused by the routing establishment due to the care-of address change are avoided. In the inter-VD routing algorithm, a vehicle can receive the data destined for the old and new care-of addresses from one access point, so the packet loss caused by the routing reestablishment due to the care-of address change is reduced. This scheme is quantitatively evaluated. Compared to the existing routing approach, our solution reduces the routing delay and packet loss by nearly 60 and 53%, respectively.