Mean Opinion Score (MOS) and Estimated Mean Opinion Score (EMOS) are originally defined for the evaluation of voice and video codecs. In this paper, we introduce the concept of the application of EMOS on industrial processes to support smart network management. We make measurements in the function of network performance on a cyber-physical system performing a sanding use case. A demonstration video is available at [1].

This paper investigates cloud-based mobile robotics, with a use case focusing on the flexible transportation in modern factories. The feasibility and performance of Autonomous Mobile Robots (AMRs) fully controlled from cloud over wireless connection are studied. We show that completely decoupling the closed-loop control of the robot from the robot’s embedded system and placing it into an edge cloud execution environment while sustaining the necessary KPIs is feasible. Moving the control logic into the cloud benefits from ease of maintenance of the control software and improved resiliency to software and hardware failures. Furthermore, it enables the physical platform and control intelligence to evolve separately from each other.

Digital Twin (DT) is widely used in various industrial sectors to optimize the operations and maintenance of physical assets, system and manufacturing processes. In this paper our goal is to introduce an architecture in which the radio access control happens automatically to minimize the utilized radio resources while still maximizing the production KPIs of the robot cell. To achieve this, we apply Reinforcement Learning (RL) in a simulated environment to explore the environment fast, while the DT ensures that the learned policy can be applied on the real world environment as well. We show that the application of Ultra Reliable Low Latency Communication (URLLC) connection can be reduced to approx. 30% of the total radio time while achieving real-world accurate robot control. The system in action can be seen on [1].

This paper analyses how much the capacity layer of HetNets are utilized as the function of momentary traffic demand and user distribution. It is shown that the capacity layer is inevitably underutilized and it is worth to apply power saving techniques to reduce the energy used by the capacity layer of the HetNet.

As for today, radio spectrum resource is rigidly partitioned for dedicated purposes. The exclusive license of fixed size spectrum blocks separated by guard bands easily solves the interference problems; however, the rigid allocation of spectrum is clearly inadequate for providing optimal spectrum efficiency for spatially and temporarily varying loads. Dynamic spectrum allocation (DSA) is a new and promising alternative where the assigned spectrum blocks may vary in time and space, too. In this paper we describe a spatio-temporal DSA model that splits the complex problem into temporal and spatial dynamic spectrum allocation. In our architecture the spectrum is allocated by regional spectrum brokers (RSB) that also coordinate spectrum access between regions. The problem of interference between different regions and providers is handled by a flexible description using the proposed geographical and radio technology coupling parameters. We also show how the optimal allocation can be found by giving the ILP solution to the problem. To evaluate the efficiency of the proposed DSA method, different gains are defined from the regulator's point of view. The performance evaluation is carried out using computer simulations, and the results are compared with the cases where either there is no interference allowed at all, or interference does not occur between regions.

In WPANs the network coverage can be extended by the formation of scatternets. As numerous papers related to Bluetooth pointed out, the performance of a WPAN highly depends on the scatternet structure. However, for high-rate WPANs (IEEE 802.15.3) the issue of scatternet formation remains unsolved. In this paper we study the performance implications of different scatternet topologies. Our analysis consisted of two levels: analytical (abstract) and practical. For the analytical level we built scatternets with integer linear programming (ILP) and heuristic methods. To see how these scatternets perform on practical level (in realistic conditions) performance analysis based on ns2 simulations was used. Our results reveal important relationships between the performance aspects and the construction of scatternets, which can serve as general guidelines for scatternet formation algorithm design

Energy efficiency is a critical issue in designing sensor networks, as the nodes have limited battery power. In this paper we propose to move the BS so as to prolong the network lifetime. We present three strategies for moving the BS: (1) minimizing the average transmission energy; (2) minimizing the maximum transmission energy; and (3) minimizing the maximum relative consumed energy for every active sensor. We examined the case, when the BS is on the optimal location in each round using the three strategies.

The speed of device discovery in Bluetooth can be unacceptably low when a higher number of Bluetooth nodes are in radio range simultaneously. In this paper we propose a practically feasible and fast alternative to the standard device discovery and link establishment protocol. The new algorithm is symmetric, and does not separate the inquiry and page phases. It causes significantly lower interference, provides better support for scatternet formation algorithms, and guarantees a reliable setup of links. Our simulation results show that for large numbers of Bluetooth devices in radio range, it operates up to 300 times faster than inquiry while consuming only 20% of power.

In this paper we propose new techniques to improve scheduling performance in time-slotted superframe based ad hoc networks. Such channel access technology is used in the IEEE 802.15.3 and 802.15.4 standards. Building on the performance analysis of previous proposals, we enhance the scheduling algorithms with flow state signaling and burst eligibility decision, so as to exploit the features of the 802.15.3 architecture. We show by simulation that the scheduling algorithms extended with these special mechanisms achieve higher performance, with better channel utilization and lower power consumption

Considering the users of a network as players competing for the network resources, the game theory seems to be a useful tool for describing the behavior of the system. Applying the rules of non-cooperative games where the players are selfish and act individually, Nash equilibria can be used to determine the "rest points" of the system. Analyzing these points by calculating the overall utility gained by the users and the overall income of the network operator, different network dimensioning strategies can be evaluated. This paper introduces evaluation of typical dimensioning strategies in DiffServ networks with different domain control setups, and with diverse user expectations in terms of QoS and price.

In the last decade two major solutions, namely IntServ and DiffServ have been introduced to empower IP networks with quality of service (QoS) capabilities. Among these two the DiffServ, which exhibits a better scalability and is the starting point for this paper is based on a per hop shaping of the traffic. The nodes control independently the flows without knowledge about the network state or/and the limitations suffered by the flows at other hops. Thus, violation of service differentiation can also occur. To correct this inefficiency a network-wide proportional service model is proposed. After presenting the theoretical argumentation and the architecture, we also provide an algorithm that computes the shaping factor needed to sustain our architecture. We use simulation experiments to validate our proposal.

The parameter estimation of a traffic model based on the fractional Brownian motion (FBM) is studied. The model has three parameters: the mean rate m, variance parameter a and the Hurst parameter H. Explicit expressions for the maximum likelihood (ML) estimates m/spl circ/ and a/spl circ/ in terms of H are given, as well as the expression for the log likelihood function from which the estimate H/spl circ/ is obtained as the maximizing argument. A geometric sequence of sampling points, t/sub i/=/spl alpha//sup i/, is introduced, which fits neatly into the self-similar property of the process and also reduces the number of samples needed to cover several time scales. It is shown that by a proper 'descaling' the traffic process is stationary on this grid leading to a Toeplitz-type covariance matrix. Approximations for the inverted covariance matrix and its determinant are introduced. The accuracy of the estimations is studied by simulations. Comparisons with estimates obtained with linear sampling and with the wavelet-based A-V estimator show that the geometrical sampling indeed improves the accuracy of the estimate H/spl circ/ with a given number of samples.