The paper describes a special case of a base station placement in wireless network with linear topology. Each station is equipped with access point (for example IEEE 802.11) that is used by the objects to send their data via the network, and with a relay equipment that allows the station to connect to the neighboring stations. Each station is described by the coverage radius and the communication radius to other stations. The goal is to determine such placement of the stations which will maximize the total coverage on the linear section by the given set of stations. Two formal problem statements are described and analyzed: the statement in the extremal combinatorial form and the formulation of the problem as a mixed-integer linear programming model. The main result is the development of a special branch and bound algorithm for solving the problem represented in the combinatorial form. The results of a comparative computational experiment by three approaches: by the brute force method, by the branch and bound algorithm and solving the problem in the form of the mixed-integer linear programming are given.

We consider a queueing-inventory problem arising in transport of passengers (flight/train/bus) in which seats in the passenger vessel are assumed to be physically available inventory. Two types of customers – type 1 (high priority (HP)) and type 2 (low priority (LP)) arrive for service. High priority customers have a finite buffer to wait whose maximum capacity is S+V , where S is the capacity of the vessel and V is the number of overbookings permitted. Low priority customers wait in an infinite capacity queue. High priority customers have non-preemptive priority over low priority customers. Arrival of customers form a marked Poisson process. Service time for each customer is exponentially distributed. Each customer asks for exactly one item from inventory which requires an exponentially distributed time for processing (reservation). The service time parameter varies with the “stage of common life time of items for reservation”. Vehicle departure time is regarded as “realization of common life time (CLT) of seats in the vehicle”. To be precise, inter departure time of vehicles is assumed to have Erlang distribution with K stages. Instantly the next vessel is scheduled. In addition to advanced reservation of seats (inventory), those customers who already reserved seats can “cancel their reservation”, before CLT gets realized. Depending on the number of overbookings, the vessel capacity for the scheduled departure is modified (for example, a larger vessel is employed if the number of overbooking at the time of departure is high enough; else the normal vessel is used). We derive the stability condition for the system. Then we go about computing the system state distribution. From these we derive expressions for computing performance of the system. Finally we analyze an optimization problem associated with the model.

In this paper we consider a two dimensional dynamical system with arbitrary piecewise constant parameters described by a linear homogeneous differential equations system with discontinuous coefficients. For such a system the fundamental solution matrix in the analytical form in elementary functions is found. The theorem saying that this matrix is the finite sum of the unimodular matrices with the certain influence coefficients is proved. The results allow us to carry out qualitative analysis of the corresponding dynamical systems, solve inverse problems, investigate the conditions for the oscillation stabilities. Obviously, the results can be used in theory of inhomogeneous and non-linear systems.

In recent years, Augmented Reality (AR) applications have appeared on smart devices (smartphones, smart glasses, etc.) that have expanded the visual perception of users. With the appearance of new technologies, a huge number of new services are created and the quality of service provision for them also plays a really important role. Thus, the task of Quality of Experience (QoE) introduces interest to suppliers, service developers and users. This article discusses the issues of QoE in the implementation of AR services in big cities with a high density of users but not all users have the Internet access. To solve this problem, we propose to use Bluetooth 5.0 technology (BLE 5.0) to access the network. The interaction between the client and the server can be carried out by using D2D communication on BLE 5.0 through smartphones of other users, which are described by the queuing system model. The proposed model of providing augmented reality services was simulated. The simulation results show delays in the delivery of data, which depends on the number of BLE 5.0 nodes through which data is exchanged between the AR client and AR server, and also on the load factor.

Currently, the methods of identification of devices of the Internet of things are one of the main topics due to the increase in the number of devices connected to the Internet. The use of a large number of heterogeneous physical and logical identifiers led to the fact that there were instances of their falsification, which threatens many vital processes. This article describes the architectural network model of a software and hardware complex for IoT device identification. Using the digital object architecture (DOA), it is possible to implement any of the heterogeneous identifiers to create a unique IoT snapshot of the device and store it with a unique global identifier. The article presents a method and developed the software-hardware system for enabling and facilitating the use of DOA for Identify IoT-devices. It is also proposed to develop a software and hardware complex for testing the identification procedure of “smart” devices using.