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The challenges of gossiping and broadcasting in ad-hoc radio networks have been well-studied.Broadcasting, or one-to-all exchange, is dissemination of a message from a single source node to all other nodes in the network. Gossiping, or all-to-all exchange, is the dissemination of a message from each node to all other nodes in the network. Many-to-all exchange, on the other hand, has gone relatively unstudied in ad-hoc radio networks. We refer to this challenge as \textit{multi-broadcasting}. Due to the unstudied nature of multi-broadcasting, the fastest previously known deterministic algorithm was the $\Tilde{O}(n^{4/3})$ proposed in \cite{Gasieniec_etal_det_gossip_04}. If a network has a set $Q$ of nodes with messages where $|Q| = q < n$, we provide three different deterministic multi-broadcasting protocols under three different models.The first assumes knowledge of both the set $Q$ and the value $q$ and runs in time $O(qn\log n\log\log n)$. The second only assumes knowledge of the value of $q$, and runs in time $O(qn\log^3n)$. The final model has the same assumptions as the second model, with the additional knowledge that the nodes of $Q$ are at most a distance $\sigma$ apart. Under this model, multi-broadcasting can be completed in time $O(q^2\sigma\Delta\log^2n)$. Lastly, we provide a protocol that can determine the correct value of $q$ in $O(\log n)$ time, thus the need for knowledge of $q$ under the second and third models is not necessary at a small additional cost in runtime.

This paper focuses on Beyond fifth generation (B5G) non-linear data modeling and decision-making tools to optimize cost reduction versus coverage-QoS trade-off, in other words, the number of active Remote Radio Heads or Units (RRHs) needed according to traffic demands. The cost and energy optimization are analytically expressed by modeling the complex relationships between input and output system parameters using realistic scenarios and traffic profiles for low, medium, and high traffic environments. The optimization tool is based on a multi-objective integer linear programming model, designed to reduce the network cost while maintaining a good coverage-QoS and accounting for capacity constraints, User Equipments (UEs), and different slices. Results at 3.6 and 28 GHz are presented by analyzing and comparing several Cloud Radio Access Network (C-RAN) split options in a heterogeneous deployment with Macro-RRHs (MRRHs) and Small-RRHs (SRRHs). Cost reductions ranging from 30 % to 70 % have been obtained depending on the scenario. This proposal allows mobile network opera This work was supported in part by the COST2020-INTERACT (Intelligence-Enabling Radio Communications for Seamless Inclusive Interactions) EU Project, in part by MCIN/AEI/10.13039/501100011033 and by ERDF A way of making Europe'' under Grant RTI2018-099880-B-C32, and in part by Grant FPI-UPC.

We study stability of routing in multi-hop wireless networks in the framework of adversarial queueing. A routing algorithm consists of three components: a transmission policy to decide on immediate transmissions, a scheduling policy to select a packet to transmit, and a hearing control to coordinate transmissions with scheduling. We consider two kinds of hearing control: proactive and reactive. We compare these policies and show relationships between the wired-network adversarial model and the multi-hop radio network model. In particular, we introduce a family of scheduling policies that are universally stable when using reactive hearing control, and obtain some stability results by using regular transmission oracles. We also prove that networks in which there is at least one node with an out-degree greater than 1 are unstable when using reactive hearing control, but all directed acyclic networks are universally stable, regardless of their out-degree, if using proactive hearing control.

We study the single-message broadcast problem in dynamic radio networks. We show that the time complexity of the problem depends on the amount of stability and connectivity of the dynamic network topology and on the adaptiveness of the adversary providing the dynamic topology. More formally, we model communication using the standard graph-based radio network model. To model the dynamic network, we use a generalization of the synchronous dynamic graph model introduced in [Kuhn et al., STOC 2010]. For integer parameters $T\geq 1$ and $k\geq 1$, we call a dynamic graph $T$-interval $k$-connected if for every interval of $T$ consecutive rounds, there exists a $k$-vertex-connected stable subgraph. Further, for an integer parameter $\tau\geq 0$, we say that the adversary providing the dynamic network is $\tau$-oblivious if for constructing the graph of some round $t$, the adversary has access to all the randomness (and states) of the algorithm up to round $t-\tau$. As our main result, we show that for any $T\geq 1$, any $k\geq 1$, and any $\tau\geq 1$, for a $\tau$-oblivious adversary, there is a distributed algorithm to broadcast a single message in time $O\big(\big(1+\frac{n}{k\cdot\min\left\{\tau,T\right\}}\big)\cdot n\log^3 n\big)$. We further show that even for large interval $k$-connectivity, efficient broadcast is not possible for the usual adaptive adversaries. For a $1$-oblivious adversary, we show that even for any $T\leq (n/k)^{1-\varepsilon}$ (for any constant $\varepsilon>0$) and for any $k\geq 1$, global broadcast in $T$-interval $k$-connected networks requires at least $\Omega(n^2/(k^2\log n))$ time. Further, for a $0$ oblivious adversary, broadcast cannot be solved in $T$-interval $k$-connected networks as long as $T, Comment: 17 pages, conference version appeared in OPODIS 2015

The traffic demand and prediction for the next decade would be mostly affiliated with the Internet of Things (IoT). Various challenges with mobile communication industry will be faced as the demand in high capacity, multi mobile devices (users) connected to the network, uplink power consumption on User Equipment (UE), and its effect on the life span of mobile phone. The major features of 5G as per user experience on the network are Ultra-Reliable Low Latency Communication (URLLC), Internet of Things (IoT), sustaining high rate Enhanced Mobile Broadband (eMBB), and connection density Massive Machine Type Communication (mMTC). This research work focuses on Non-Standalone (NSA) 5G New Radio (NR) early deployment on eMBB for achieving the required throughput. The 5G performance requirement is higher than 4G, which includes the capacity to support user experience downlink throughput with target value of 1 Gbps, millisecond-level of end-to-end latency, and high connection density of 1 million per square kilometer. Optimization is a vast topic, and this paper discusses the problems faced by users latching on 5G NSA network on the downlink and 4G Network on the uplink and suggests its solution.

5G is the future generation network offering the variety of changes in the architecture of the core network. The network function virtualization and software-defined networking provide unconditional support to the emerging 5G network. This chapter highlights the evolutionary changes from 1G to 5G networks. Then it covers the important aspects for the realization of the 5G networks comprising the management of radio network, providing network service, mobility issue, and so on. This covers the complicated configuration issues and challenges for the future 5G network. Then it also creates a vision to solve the issue and overcome the challenges in 5G network by using the artificial intelligence (AI). Including the AI concepts to empower the 5G networks to meet the challenges of future generation networks. So, the main focus is to empower the 5G network with AI to acclaim intelligent 5G as a reality.

In this paper we present a framework for leader election in multi-hop radio networks which yield randomized leader elections taking O ( broadcasting time ) in expectation, and another which yields algorithms taking fixed time of the order of O ( log ⁡ n ) -times broadcasting time. Both succeed with high probability. We show how to implement these frameworks in radio networks without collision detection, and in networks with collision detection (in fact in the strictly weaker beep model). In doing so, we obtain the first optimal expected-time leader election algorithms in both settings, and also improve the worst-case running time in directed networks without collision detection by an O ( log ⁡ n ) factor.

Cognitive radio networks (CRNs) have the capacity to be aware of the conditions of their operating environment, and dynamically reconfigure their own characteristics in order to reach the best available performances. These performances may be seriously impacted when the number of users in CRNs grows significantly. This study deals with efficient energy consumption and interference avoidance in large CRNs. To enhance the network lifetime, a new framework combining cognitive hierarchical clustering and the coalitional game is introduced. In this study, a new CRLEACH protocol is proposed and the well-known LEACH protocol is used in CRNs. The authors prove theoretically that their coalition model with a new strategic learning algorithm leads to Nash equilibrium. Finally, the network performances of their framework are illustrated by numerical results.

Mostly natural disasters in Java Island such as landslides are within the vicinity of not more than 200 Km from the district capital. Cellular communications require complex systems and rather vulnerable  to cope with disasters. NVIS mode is considered as a simple radio link during disaster mitigation initiation process. It needs a valid estimation to figure out the condition of the ionosphere. There are two purposes of this study, the first of which is an attempt to find out a fact the existences of authorized HF users who still work in the band of 3 MHz – 10 MHz. The second is to integrate low cost HF radio communication, commonly available small single board computer hardware, and opensource software, to build a sounding system to evaluate the quality of NVIS channels. Prediction system such VOACAP give hourly prediction data, however it has an inherent limitation because of  nature the underlying databases is monthly average based, therefore, the estimation could not be made in a daily bases. However, a real-time channel evaluation (RTCE) able to purify maximum observed frequency (MOF) estimation, and consequently, its able to select the best available frequency for short term and real time operation. In this study, we used WSPR to perform a simple RTCE technique. Furthermore, we also reviewed the current regulatory status regarding the availability of sub-10 MHz band for NVIS radio operation. The results show that discrepancies between simulation and measurement are occurred mainly because of sporadic data in the band of 60m and 80m. However, all of the measurement results and simulations almost have the same agreement regarding the quiet period between local midnight and local sunrise. The results of measurements show that 60m band is the most reliable NVIS channel between local sunrise and local midnight. Furthermore, 100 watts is a proper transmitter power to reach the required SNR for reliable voice communication.Â

Hybrid, mixed analogue/digital beam-forming architectures are a central research topic for the development of mm-wave communication for fifth generation. Most approaches are based on phase shifters in the analogue part, which are inherently narrowband. In this study, the authors evaluate the effects and performance of narrowband beam-steering on wideband signals using two different modelling approaches: spatial-narrowband model, in which the inter-antenna element delays are neglected, and spatial-wideband model, in which the inter-antenna element delays are considered. They show that neglecting the spatial-wideband effects on channel models overestimates the focusing of beam-forming, the expected delay spread reduction, and achievable data-rate with an increasing number of antennas and bandwidth. These effects are quantised by simulations using a realistic ray-tracing scenario at 60 GHz.

These days, the growth of media usage has encouraged the development of new media in quantity and the form itself. With these amount of media development, it leads to the inevitable competition. Radio is no exception. Today, the phenomenon of Radio Network development in Indonesia is very rife. If we see this networking practice between radio(s), then we will find a strong bond that will give many advantages for the main radio of the holdings. However, Gen FM which has their radio network in Surabaya, gives the freedom to their radio network to grow by their own. In fact, both of these radio are successfully topped the Nielsen Research. This research uses qualitative method and aim to find out how the production management program conducted by Gen FM to its radio network. The result of this study indicate that the production management program on Gen FM radio runs very well in accordance with the elements of broadcasting management including planning, organizing, actuating, and controlling. Thereby, two of these radio network can compete on the top list of Nielsen.

We consider the energy complexity of the leader election problem in the single-hop radio network model, where each device has a unique identifier in $\{1, 2, \ldots, N\}$. Energy is a scarce resource for small battery-powered devices. For such devices, most of the energy is often spent on communication, not on computation. To approximate the actual energy cost, the energy complexity of an algorithm is defined as the maximum over all devices of the number of time slots where the device transmits or listens. Much progress has been made in understanding the energy complexity of leader election in radio networks, but very little is known about the trade-off between time and energy. $\textbf{Time-energy trade-off:}$ For any $k \geq \log \log N$, we show that a leader among at most $n$ devices can be elected deterministically in $O(k \cdot n^{1+\epsilon}) + O(k \cdot N^{1/k})$ time and $O(k)$ energy if each device can simultaneously transmit and listen, where $\epsilon > 0$ is any small constant. This improves upon the previous $O(N)$-time $O(\log \log N)$-energy algorithm by Chang et al. [STOC 2017]. We provide lower bounds to show that the time-energy trade-off of our algorithm is near-optimal. $\textbf{Dense instances:}$ For the dense instances where the number of devices is $n = \Theta(N)$, we design a deterministic leader election algorithm using only $O(1)$ energy. This improves upon the $O(\log^* N)$-energy algorithm by Jurdzi\'{n}ski et al. [PODC 2002] and the $O(\alpha(N))$-energy algorithm by Chang et al. [STOC 2017]. More specifically, we show that the optimal deterministic energy complexity of leader election is $\Theta\left(\max\left\{1, \log \frac{N}{n}\right\}\right)$ if the devices cannot simultaneously transmit and listen, and it is $\Theta\left(\max\left\{1, \log \log \frac{N}{n}\right\}\right)$ if they can.

Intelligent Transport Systems (ITS) are fundamental to reaching the concept of smart cities. However, the incoming development of vehicular applications will originate an increase in long-term evolution (LTE) traffic demand, so an approach consists of reducing the cell coverage area. This paper presents an alternative solution to deal with areas with a lack of coverage originated by the deployment of LTE micro-cells.We propose a heterogeneous network algorithm named Multi-Metric Heterogeneous Network Algorithm(MMHNA), which uses LTE and dedicated short-range communications (DSRC) technologies. The objective is to extend the LTE communication range with the support of DSRC technology through a forwarding process. This proposal will allow vehicles to send messages to a server directly connected to the evolved Node B (eNB), i.e., the radio network node for LTE networks, even if the sending vehicle is out of range of the eNB. This work was supported by the Spanish Government under research projects “sMArt Grid using Open Source intelligence (MAGOS)" TEC2017-84197-C4-3-R and “Enhancing Communication Protocols with Machine Learning while Protecting Sensitive Data (COMPROMISE)" (PID2020-113795RB-C31/AEI/10.13039/501100011033). Xavier Calle Heredia and Pablo Barbecho Bautista are recipient of a full scholarship from the Secretaria Nacional de Educación Superior, Ciencia y Tecnología (SENESCYT).

One of the most challenging applications targeted by evolving (beyond-)5G technology is virtual reality (VR). Particularly, 'Social VR' applications provide a fully immersive experience and sense of togetherness to users residing at different locations. To support such applications the network must deal with huge traffic demands, while keeping end-to-end latencies low. Moreover, the radio access network must deal with the volatility and vulnerability of mmWave radio channels, where even small movements of the users may have substantial effects on the Quality of Experience. We present an integral modelling framework for feasibility assessment and performance optimization of the radio access network for Social VR applications in indoor office scenarios. Using the presented modelling approach, we conduct an extensive simulation-based assessment to determine the performance impact of head motion, the frequency band (3.5 GHz, 26 GHz) and radio network configurations, and derive the required carrier bandwidth for a range of 'Social VR' scenarios. Insights into these issues are a prerequisite for setting up guidelines for network deployment and configuration as well as for the development of (AI/ML-based) methods for dynamic resource management to optimally support Social VR applications.

Here is an example of how the fourth generation of cellular networks is developing rapidly today. The traffic per subscriber is growing every month. Operators are forced to provide coverage and the necessary capacity by installing new base stations. Quality network planning can provide better network performance and reduce deployment and optimization costs. It is also important to use a planning and optimization tool to model network coverage and perform performance analysis. According to the results of many studies, the amount of data transmitted over wireless networks has been growing significantly recently. Buildings are obstacles to the signal over long distances, so for the same area in different types of terrain for quality coverage it is necessary to place a different number of base stations. In addition, it is necessary to take into account the peculiarities of the building, as signals from different base stations are an obstacle for each other. On the other hand, high population density requires a large network capacity to meet the needs for speed and number of simultaneously connected users. Traffic is projected to increase by 2024, due to the emergence of new video services and the growing popularity and involvement of the population in existing ones. LTE-Advanced provides the ability to deploy repeaters to increase network performance. In the context of cellular communication systems, an important aspect is radio network planning - the process of locating base stations, determining the frequency channels and radio parameters of a wireless communication system to provide sufficient coverage and connection capacity to ensure the required level of service quality. to the user. Coverage planning refers to a geographic area where the network must provide a signal with sufficient power to provide access to voice or packet services, and capacity planning determines the system’s ability to provide services to a given number of subscribers. The purpose of the article is to study the process of planning the fourth generation LTE network in terms of urban development, calculations and modeling of coverage.

This chapter presents cooperative relaying networks that are helpful in Internet of Thing (IoT) applications for fifth-generation (5G) radio networks. It provides reliable connectivity as the wireless device is out of range from cellular network, high throughput gains and enhance the lifetime of wireless networks. These features can be achieved by designing the advanced protocols. The design of advanced protocols plays an important role to combat the effect of channel fading, data packet scheduling at the buffered relay, average delay, and traffic intensity. To achieve our goals, we consider two-way cooperative buffered relay networks and then investigate advanced protocols such as without channel state information (CSI) i.e., buffer state information (BSI) only and with partial transmit CSI i.e., BSI/CSI with the assistance of one dimensional Markov chain and transmission policies in fading environment. The outage probability of consecutive links and outage probability of multi-access and broadcast channels are provided in closed-form. Further, the buffered relay achieves maximum throughput gains in closed-form for all these protocols. The objective function of throughput of the buffered relay is evaluated in fractional programming that is transformed into linear program using standard CVX tool. Numerical results show that our proposed protocols performance better as compared to conventional method studied in the literature. Finally, this chapter provides possible future research directions.

Indoor positioning methods using radio networks are investigated. Time Difference of Arrival (TDOA) method is studied deeply, and the main problems are revealed. Application of ultra-wide band (UWB) radio technology to TDOA method is discussed, and limitations to UWB receiver and transmitter are revealed. These results are of great importance for the organization of unmanned moving devices management in the paradigm of fully autonomous Fabric of the Future in Industry 4.0.

Cognitive Ad Hoc Radio Networks (CRAHNs) is a technology which has been introduced to deal with the problem of spectrum depletion. CRAHNs address the spectrum depletion problem by letting unlicensed users also called Secondary Users (SUs) recycle unused spectrum bands according to the activities of the of the licensed users/ Primary Users (PUs). CRAHNs have now been implemented in military networks and are called military CRAHNs (MCRAHNs). Routing in MCRAHNs often results in a lot of spectrum switching done by the SUs. In the process of switching between spectrum bands, a lot of data packets are dropped by the SUs which results in a low throughput and high packet drop rate. This study proposes a new routing technique optimized for MCRAHNs which is optimized for throughput and reduces packet drop rate by more than 40%. This new technique uses network coding rather than normal packet relaying to forward packets between nodes. It also uses an algorithm based on the Jacobian equations and the Markov chains to ensure that most forwarded packets reach their destination in the required time.

The paper discusses a method related to radio communication, namely subscriber authentication, which can be used as a separate element when building authentication systems designed to identify subscribers in radio networks.

Results of experimental verification of the proposed analytical technique for calculation of the average electromagnetic background (EMB) intensity created by base stations of cellular communications, which is based on estimation of the average electromagnetic loading on area (EMLA) created by base stations, are presented. This verification is executed by comparison of the published results of measurements of levels of EMB generated by 2G/3G radio networks in more than 30 countries, with the results of corresponding analytical worst-case estimations of EMLA and average EMB intensity for the real and potential places of EMB measurements. Results of this comparison convincingly confirm the adequacy of the offered analytical technique for worst-case estimation of EMB created by mobile (cellular) communications, and also support its real practical importance for an assessment of electromagnetic ecology of various areas, electromagnetic safety of population and intersystem EMC in conditions of extremely fast development of radio networks and services of 4G/5G/6G.

In this paper, we consider the problem of broadcast from a specified source node in a known synchronous radio network. In 2019, Ellen, Gorain, Miller and Plc showed that this is possible if each node in the network only stores 2 (carefully chosen) bits of information. They proved that in an n-node network, their algorithm ensures that the broadcast completes within 2n-3 rounds. We show that storing only a small constant number of additional bits, it is possible to broadcast significantly faster when the source eccentricity, D, of the network is o(n). We begin by presenting a modification of Ellen, Gorain, Miller and Pelc's algorithm that stores 4 bits per node and completes within O(√Dn) rounds. Then we define a class of broadcast algorithms that includes both these algorithms and prove that any algorithm in this class requires Ω(√nD) rounds. Next, we show (non-constructively) that there exists a broadcast algorithm which stores only 3 bits of information per node, but completes within O(D log n+log2 n) rounds. Finally, using ideas from Chlamtac and Weinstein (1991), we show how to construct the relevant information and do almost as well, giving an algorithm using 3 bits per node that runs in O(D log^2 n) rounds.

Inspired by a new feature in 5G NR called bandwidth part (BWP), this paper presents a bandwidth allocation (BA) model that allows one to adapt the bandwidth allocated to users depending on their data rate needs. Specifically, in adaptive BA, a wide bandwidth is divided into chunks of smaller bandwidths and the number of bandwidth chunks allocated to a user depends on its needs or type. Although BWP in 5G NR mandates allocation of a set of contiguous bandwidth chunks, our BA model also allows other assumptions on chunk allocation such as the allocation of any set of bandwidth chunks, as in, e.g., LTE resource allocation, where chunks are selected uniformly at random. The BA model studied here is probabilistic in that the user locations are assumed to form a realization of a Poisson point process and each user decides independently to be of a certain type with some probability. This model allows one to quantify spectrum sharing and service differentiation in this context, namely to predict what performance a user gets depending on its type as well as the overall performance. This is based on exact representations of key performance metrics for each user type, namely its success probability, the meta distribution of its signal-to-interference ratio, and its Shannon throughput. We show that, surprisingly, the higher traffic variability stemming from adaptive BA is beneficial: when comparing two networks using adaptive BA and having the same mean signal and the same mean interference powers, the network with higher traffic variability performs better for all these performance metrics. With respect to Shannon throughput, we observe that our BA model is roughly egalitarian per Hertz and leads to a linear service differentiation in aggregated throughput value., Comment: IEEE INFOCOM 2020

this article discusses the features of simulation short-pulse ultra-wideband radio communication systems in the organization of communication networks in autonomous groups of unmanned aerial vehicles. The model of the ultra-wideband radio system and factors affecting the parameters of the communication network that arise when constructing a radio network in a mobile unmanned aerial vehicles group (that changes its configuration and altitude during the flight) are considered. The results of modeling such a radio system are presented, the requirements for the radio system and recommendations for its construction are formulated.

The large available bandwidths at millimeter-wave (mmW) frequencies enable very high data rates and reduced latencies while can also facilitate high-resolution radio-based sensing. In this paper, we address the problem of providing the communications and sensing functionalities simultaneously at the same frequencies, with specific emphasis on the emerging 5G New Radio (NR) networks. To this end, a novel RF beamforming design and optimization approach is proposed, for dual-functional joint radar-communication systems, providing multiple simultaneous transmit beams to support efficient beamformed communications while an additional beam simultaneously senses the environment around the base-station. The proposed beamforming approach jointly optimizes the transmitter and receiver beamforming weights in order to maximize the sensing performance and mitigate the possible interference stemming from the communication beam, while guaranteeing also the target beamforming gain for the communications link. The performance of the proposed approach is assessed through comprehensive numerical evaluations, demonstrating that substantial gains and benefits can be achieved compared to more ordinary beamforming approaches. acceptedVersion

Trilateration is the mathematical theory of computing the intersection of circles. These circles may be obtained by time of flight (ToF) measurements in radio systems, as well as laser, radar and s ...

An algorithm proposed for searching the topology of the ground-to-air radio network (GARN) to ensure the connectivity of ground nodes and improve the quality of their service. The search for a solution for the implementation of the target functions of network management is carried out by directed enumeration of options for the position of telecommunication aerial platforms (TA).

The Universal Mobile Telecommunications System (UMTS) is a third generation wireless telecommunication system based on W-CDMA technology, and is normally the solution generally preferred by most countries. Nowadays UMTS has become an everyday technology from the user perspective in most countries. Over the years, the UMTS radio network system has been significantly enhanced and now offers broadband speeds far beyond the original design.

Рассматривается проблема проведения измерений с целью обеспечения электромагнитной совместимости (ЭМС) сетей 5G NR. Анализируются принятая последовательность внедрения новой технологии радиосвязи, а также специфика предусмотренного для нее частотного плана и ее физического уровня, которые определяют важнейшие особенности измерений в обеспечение межсистемной ЭМС., The article deals with the problem of making measurements to ensure EMC for 5G NR networks. The adopted sequence for the introduction of a new radio communication technology, the features of the frequency plan and its physical level, which determine the most important features of measurements to ensure intersystem EMC, are analyzed., Электросвязь, Выпуск 10 (11) 2020

In 2008, the Federal Communications Commission issued a ruling permitting the unlicensed usage of TV white spaces (TVWS), i.e. locally vacant TV channels. Due to its low-frequency range (50-698 MHz), the TV spectrum has much better propagation characteristic and higher-spectral efficiency, resulting in a wide range of potentially important applications. However, unlike typical cellular and industrial scientific medical bands, TVWS are subjected to high-spatial variation, temporal variation, and fragmentation, resulting in new challenges in TVWS identification and in implementing a wireless network in this band. Identification and network design are the two key issues required to be addressed while investigating TVWS. These two problems have been widely discussed in several existing literature. Applications in TVWS are also an important topic, which has not been adequately explored. This study provides an up-to-date survey of TVWS and its applications in future wireless networks and communication. Various problems and challenges associated with each use case as well as the possible enabling methods to address these challenges are also presented.

Security has been and will probably be one of the basic human needs that we work on every day. Some of the popular options nowadays is the use of modern technologies in security, which is increasingly popular with alarm systems. Mostly alarm systems are electrical security systems, which in many cases can be supplemented by various additional functions according to the owner's requirements. More often, they are also able to connect a secured object to a centralized protection center so that the owner has the possibility of verifying a declared alarm signal through the intervention of the alarm system company operator.This article is aimed at transmitting the indicated alarm signal over a radio network to the centralized protection desk located in the monitoring and alarm receiving center with identification of the most appropriate option.

Cognitive radio networks are a promising technology for the improvement of the spectrum utilisation. The basic idea is to maximise the utilisation of the available spectrum by dynamically assigning available channels to secondary users. This problem known as the spectrum allocation problem is non-deterministic polynomial-time hard (NP-hard). Chaotic biogeography-based optimisation (CBBO) is a recently proposed evolutionary algorithm that can be applied to the above-mentioned problem. The authors compare CBBO with other popular algorithms in different spectrum allocation problem cases. The results show that CBBO performs in general better or similar to the other algorithms.

In this paper, we are interested in symbiotic radio networks, in which an Internet-of-Things (IoT) network parasitizes in a primary network to achieve spectrum-, energy-, and infrastructure-efficient communications. Specifically, the BS serves multiple cellular users using time division multiple access (TDMA) and each IoT device is associated with one cellular user for information transmission. We focus on the user association problem, whose objective is to link each IoT device to an appropriate cellular user by maximizing the sum rate of all IoT devices. However, the difficulty in obtaining the full real-time channel information makes it difficult to design an optimal policy for this problem. To overcome this issue, we propose two deep reinforcement learning (DRL) algorithms, both use the historical information to infer the current information in order to make appropriate decisions. One algorithm, centralized DRL, makes decisions for all IoT devices at one time with global information. The other algorithm, distributed DRL, makes a decision only for one IoT device at one time using local information. Finally, simulation results show that the two DRL algorithms achieve comparable performance as the optimal user association policy which requires perfect real-time information, and the distributed DRL algorithm has the advantage of scalability., 12 pages, 11 figures

Background. Development of methods and means of the adaptive management of the radio networks bandwidth with competitive access to the radio channel. Objective. The aim of the paper is to determine the packet length effect on the effective radio networks transmission rate with taking into account the parameters, formats , and procedures of the physical and link levels at using the MAC protocol with a rigid strategy of competitive access to the radio channel. Methods. The goal is achieved by creating and analyzing the mathematical model of the effective transmission rate in radio networks. The model is described by the equation for the effective transmission rate, which is the function of both the probability of the conflict-free transmission of the MAC protocol and the coefficient of the data packet size deviation from the optimal for LLC protocol. Results. It is proved that there is the optimal deviation of the data packet length for each MAC protocol traffic intensity value, which provides the most effective transfer rate. This makes the possibility for adaptive management of the radio bandwidth by applying a pre-calculated deviation of the data packet size in dependence on the traffic intensity. Conclusions. The proposed mathematical model is the tool for calculation of both the radio bandwidth network capacity and the optimal deviation of the data packet length at adaptive management of competitive access to a radio channel with a rigid strategy at conditions of the significant fluctuation in traffic intensity.

A new utility function-based framework is proposed for network selection that utilises exponential functions and is monotonically related to a function of the average of additive and multiplicative utility functions. This means that an intermediate solution has been identified that not only includes inter-dependencies of performance criteria but also reduces the network elimination. Numerical results compare the performance of the existing and proposed utility functions and it can be seen that the proposed utility function is a good choice for network selection.

In a Cooperative Spectrum Sensing environment, malicious secondary users (SU) degrade the overall performance of the radio network. The existing techniques need to assume an upper bound on the number of such users in a network, to identify them. In the present work, we use the robust distance based on minimum covariance determinant (MCD) to identify the malicious users in the network without assuming such an upper bound. Further, we validate the performance of the proposed RD method in random, always high and always low selfish attacks scenarios.

The Spectrum Collaboration Challenge (SC2) was started by DARPA in 2016 to further expand the research on spectrum usage efficiency, and mitigate the ever-growing problem of spectrum scarcity. Teams that participated in SC2 designed and developed wireless networks, called Collaborative Intelligent Radio networks (CIRNs), to compete with other teams’ CIRNs. The scoring system was created to motivate maximizing both their own and other networks’ data throughput. To improve the spectrum usage efficiency, teams were encouraged to use Artificial Intelligence, as well as to collaborate with other teams and agree on spectrum usage schedules that work best for all parties. To facilitate this collaboration, DARPA has established the CIRN Interaction Language (CIL) – a language CIRNs can use to communicate with other networks and establish common spectrum goals and ways to achieve them. One of CIL’s main functionalities was to enable teams to announce their intended spectrum usage and provide information other teams can use to adapt their own channel selection. While potentially a beneficial concept, CIL’s effect on ensemble throughput of all networks was never evaluated, as a proper evaluation framework was never provided by DARPA, since it was not possible to disable it. This paper describes a simplified simulation of the spectrum usage announcement functionality of the CIL, explains the experiments run to evaluate CILs gains, and showcases the obtained results.

Current trends in ultra-dense radio networks include wide utilization of beamforming techniques. Successful implementation of simultaneous transmission and reception is possible by means of preliminary location of neighboring stations. Contribution of the current research is location accuracy limits estimation for positioning of radio emission sources using time difference of arrival in 3D with sensors aboard UAV. Resulting accuracy limits, such as Cramer-Rao lower bound ellipsoid and spherical error probability contour were analyzed and visualized to confirm spatial splitting possibility of neighboring RES in dedicated short-range communications for 200 m separation in dense-urban scenario.