An approach to determining the bandwidth of the self-healing segment of the data network is proposed. The subject of the study are autonomous segments of the telecommunications network, which have the property of self-healing. The object of research is the process of information transfer between nodes of an autonomous segment. The scientific novelty is to improve the method of determining the capacity of the self-healing segment of the telecommunications network with limited network resources by applying the criterion of ensuring the minimum time of information delivery at a given limit of possible probability of loss. The following tasks were solved: a mathematical model of the self-healing segment of the telecommunication network in the form of a queuing system was developed; the proposed method of calculating the degree of channel congestion. Conclusion: the proposed approach made it possible to calculate the bandwidth of the communication channels of the self-healing segment of the telecommunications network and the required amount of buffer memory with a known network topology and a given gravity matrix, providing the required values of failure probability and guarantee minimum message delivery time.

One of the most important and integral components of modern computer security are access control systems. The objective of an access control system (ACS) is often described in terms of protecting system resources against inappropriate or unwanted user access. However, a large degree of sharing can interfere with the protection of resources, so a sufficiently detailed AC policy should allow selective exchange of information when, in its absence, sharing can be considered too risky in general. Erroneous configurations, faulty policies, as well as flaws in the implementation of software can lead to global insecurity. Identifying the differences between policy specifications and their intended functions is crucial because the correct implementation and enforcement of the policies of a particular application is based on the premise that the specifications of this policy are correct. As a result of the policy, the specifications presented by the models must undergo rigorous validation and legalization through systematic checks and tests to ensure that the specifications of the policies really correspond to the wishes of the creators. Verifying that access control policies and models are consistent is not a trivial and critical task. And one of the important aspects of such a check is a formal check for inconsistency and incompleteness of the model, and the security requirements of the policy, because the access control model and its implementation do not necessarily express policies that can also be hidden, embedded by mixing with direct access restrictions or another access control model.

No abstract

No abstract

The modern development of mobile communications applied in remote sensing techniques requires continuous improvement of methods for transmitting information and developing new types of signals in order to achieve better resistance to interference, energy and structural secrecy of radiation, increase the efficiency of radio systems. These features have broad spectrum signals, the main advantages of which are: ensuring confidential transmission of information, extracting the signal from below the noise level, ensuring the reliability of the received information, even with a relatively small signal-to-noise ratio (SNR). Traditionally, the expansion of the spectrum of signals is done by multiplying the information signal by a code sequence, which is a random sequence, most often of binary symbols, formed by a determined law, but having the properties of a random sequence. Different classes of code sequences are known and used, which meet a number of mandatory requirements. However, they all have one or another drawback. An important reason for this is the lack of a universal mathematical apparatus through which to form a random sequence with the necessary structural complexity and correlation properties to ensure confidentiality in the transmission of information. With the emergence of a new direction in the development of communication technologies, based on the theory of dynamic chaos, there are alternative opportunities to expand the spectrum of signals. These are discrete chaotic signals, which, like pseudo-random sequences, are characterized by a quasi-continuous spectrum with uniform spectral density, with a steeply decreasing autocorrelation function and orthogonality. In the present work a structural scheme of a communication system between sensors is proposed, in which the spectrum of the information signal is expanded by a chaotic sequence. The noise immunity of the system is assessed by determining the probability of bit error rate (BER). The dependence of BER on SNR is studied. The connection with remote sensing could be review in the field wireless network using nodes. The methodology is tested in a simulation and in in-situ experiments. Some of the nodes are coated by new material and put into extreme conditions. The obtained results are analyzed and discussed.