Currently, Cellular Networks are one of the essential communication methods for people. Providing proper coverage for the users and also offering high-quality services to them are two of the most important issues of concern in Cellular Networks. The fifth-generation Cellular communication Networks can provide higher data transmission rates, which lead to a higher quality of service but this higher rate has let to reduced antenna coverage in these Networks. Besides this, natural and unnatural events in the environment can also affect the coverage of users in the Cellular Network. One way to resolve this issue is using drones as Cellular antennas. The most important factor in providing good coverage and high-quality service for users is the optimal placement of antennas. In this article, the problem of finding the appropriate locations of drone base stations (DBSs) is modeled as a P-median optimization problem, where P is the number of required antennas to cover the users. We have used a fuzzy clustering algorithm to define a set of specified candidate points that are required to select the locations of DBSs in the P-median model. The optimal value of P was obtained using the bisection algorithm. Finally, the optimal positions of DBSs have been determined by solving the optimization problem. According to the results, in the case of a proper selection of fuzzy clustering parameters, better results will be obtained in comparison to the results of other approaches.

As mobile data traffic increases, and the number of services provided by the mobile Network increases, service load flows as well, which requires changing in the principles, models, and strategies for media transmission streams serving to guarantee the given nature of giving a wide scope of services in Flexible and cost-effective. Right now, the fundamental question remains what number of Network slices will be cost effective for slice managing and giving the required functionality. So, the aim is to improve the efficiency of mobile Network by forming an ideal slice in a multi-service communication Network. In this paper, we propose a model to demonstrate Network resource allocation system that forms devoted Network slices to serve particular types of services independently on shared infrastructure. This model solves the problem of creating a strategy to form multi-service core mobile communication Network slices, which allow the providing of a wide scope of services with certain quality indicators according to the effective dynamic configuration of the system. A resource management system model is created, to provide a method that considers costs related with excessive resource allocation, and also reduces the number of Network recalculations, allowing for a reasonable proportion of management costs and Qualities of Service.

Today, considering the increasing trend of urbanization and progressive growth of the city and citizens’ hazards regarding the environmental and technological risks and social challenges, the necessity of regarding safety issues as one of the important and determinant factors of a sustainable city is sensed more than before.Karaj, the young metropolis that less than 50 years is passed from its new life, is of the cities that with respect to its rapid changes and evolution from scattered rural settlements with 14’226 population in 1335 to the current metropolis with population of 1’386’030, has made inevitable the safety management of hazardous phenomenon.To obtain the perspective of Karaj safety plan and decreasing the undesirable effects of crisis and events, recognizing and evaluation of physical safety of the city and spatial modeling of these components in 34 regions are the aims of this research. Establishment of descriptive data bank, Combining it with spatial data and finally its spatial modeling in the form of GIS Cellular Network and AHP are the considered methodology in this study.The research findings showed that among the tenth physical safety indicators, impermeability with weighting value of 0.79 out of 1 has the highest rank, district No.1 with physical safety coefficient of 0.50 of 1 is the most unsafe district and district No.20 with safety coefficient of 0.73 has been recognized as the safest region.

In this paper, beamforming and consumed power minimization in base station is studied for an underlay device-to-device communication within a Cellular Network. It is assumed that the channel state information are not available at the base station, and only estimations of their covariance are available. The estimation errors are considered in two models. In the first model, the errors are upper bounded in their Frobenius norms and the goal is to find the beamforming in the base station in order to minimize the consumed power in BS under the constraint that the signal to interference plus noise ratio for users are guaranteed to be above a certain predefined threshold. In the second model, a probabilistic model is considered for the uncertainty of channel covariance matrices and the BS consumed power is minimized while the non-outage probability of users are guaranteed to be above a certain predefined threshold. Although our approaches initially lead to non-convex optimization problems, they can be reformulated in convex forms by using the semidefinite relaxation technique to find lower bounds for them. Simulation results show that our proposed methods outperform Hybrid MRT-ZF, ZFBF and MRT beamforming schemes.

Due to the explosion of smart devices, data traffic over Cellular Networks has seen an exponential rise in recent years. This increase in mobile data traffic has caused an immediate need for offloading traffic from operators. Device-to-Device (D2D) communication is a promising solution to boost the capacity of Cellular Networks and alleviate the heavy burden on backhaul links. However, direct wireless connections between devices in D2D communication are vulnerable to certain security threats. In this paper, we propose an incentive-aware lightweight secure data sharing scheme for D2D communication. We have considered the major security challenges of the data sharing scheme, including data confidentiality, integrity, detecting message modification, and preventing the propagation of malformed data. We have also applied an incentive mechanism to motivate users involvement in the process of data sharing. Actually, D2D communication is highly dependent on user participation in sharing content, so, we apply the concept of âAIvirtual checkâAI to motivate users (named proxy users) to help the requesting user (client) in the process of obtaining the data. Unlike the previous studies, our proposed protocol is an stateless protocol and does not depend on the userâAZs contextual information. Therefore, it can be used at anytime and from anywhere. The security analysis proves that the proposed protocol resists the security attacks and meets the security requirements. The performance evaluation shows that the proposed protocol outperforms the previous works in terms of communication and computation cost. Thus, the proposed protocol is indeed an efficient and practical solution for secure data sharing in D2D communication.

New emerging industries, such as vertical markets, need diverse Networking requirements that the next generation mobile Networks have to support effectively. Network slicing is the basic solution to meet the diverse requirements of various services over a common Network infrastructure. Different Network slicing architectures have been proposed; however, to the best of our knowledge, there is no unified architecture to cover all aspects of technology. In this paper, we propose a complete Network slicing architecture based on 3GPP 5G system that addresses a unified end-to-end approach. We show how this architecture can create and operate various slices in the core and radio access sections using SDN controllers, virtualization, NFV MANO, and 3GPP management functions. We do compare our proposed one with some famous Network-slicing architectures. The Comparison Results show that our proposed architecture is complete and covers all the aspects of Network slicing. It uses NFV management and orchestration capabilities and SDN controllers while being compatible with 3GPP Service-Based architecture. It also provides life cycle management of Network slices in both creation and operation phases in both core and radio access domains of the 5G Network. In addition, we have included a functional RAN layer split to lay the corresponding layers in centralized or distributed units according to the requirements of each eMBB, mMTC, or URLLC slice.

Vertical handover is the essential feature of the next generation heterogeneous wireless Networks. Network selection among accessible candidates is the most critical step in vertical handover procedure. Although various algorithms for Network selection have been proposed, due to different approaches and diversity of parameters corresponding to this complicated problem, no unified benchmark or global indicator exists to evaluate the performances. In this paper, we define a global performance indicator (GPI) which comprehensively considers all subscriber satisfaction factors to assess users’ quality of experience (QoE). Our method is inspired by “ Analytic Hierarchical Process” (AHP) and systematically utilizes both customer and Network side parameters. This idea was led to propose a novel “ automatic context-aware Network selection” (ACANS) algorithm. ACANS is a “ Network-assisted” , “ user centric” approach which dynamically and automatically affects customer context in the decision of the best Network. A practical simulation platform evaluates and compares ACANS to well-known Network selection algorithms such as SAW (Simple Additive Weighting), MEW (Multiplicative Exponential Weighting), TOPSIS (Technique for Order Preference by Similarity to Ideal Solution) and TRUST (TRigger-based aUtomatic Subjective weighTing). Simulation results show that the proposed algorithm is compatible to customer preference and has superior performance in “ No. of handovers” , “ user’ s volume of download” , “ consumed energy” and “ service cost” .

Millimeter wave (mW) communication is one of the key enabling technologies for meeting the vast data demand growth and bandwith scarcity. It offers higher bandwidth which resuls in higher capacity. To improve the user experience in the 5G communication, it is proposed to utilize the composition of microwave (μ, W) and mW Networks. On the other hand, an ultra-dense Network (UDN) has been envisioned as a promising Network paradigm for spectrum efficiency (SE) enhancement. In this paper, the Cellular Network using TDD duplexing, consists of both mW and μ, W base stations. BSs and users are distributed in indoor and outdoor environments. Our aim is to calculate the spectral efficiency for both mW and μ, W sysyems, based on the BSs and users distribution. Moreover, the effect of BS density on spectral efficiency is evaluated. Finally, the problem of maximizing the downlink rate is formulated and solved as a linear optimization problem so that the minimum uplink rate is guaranted. The simulation results show that by servicing both mW and μ, W simultaneously on uplink and downlink, high SE can be achieved and with the help of optimal resources allocation, the Network’, s perfomance is improved significantly.