Pavlina Koleva

Challenges in designing and implementation of an effective Ambient Assisted Living system

In this paper some challenges in the design and realization of an effective Ambient Assisted Living (AAL) system are discussed. Solutions to meet those challenges are proposed. Example of the practical implementation of the architecture of an AAL system - “eWall for Active Long Living” (eWALL) and the related context-aware services are presented.

Heuristic approach to dynamic Uplink Power Control in LTE

In this paper an approach for Uplink Power Control for Long Term Evolution is proposed. The developed method is based on a heuristic algorithm for the division of the users in mobile cell into sets with different uplink power settings. By applying such an approach, a dynamic power control mechanism could be implemented depending on the distribution, location and the required throughput of the User Equipments in the cell with minimum Inter-Cell Interference. The results from the simulation experiments show that such approach could be an effective solution for dynamic Uplink Power Control.

Resource Management Based on Dynamic Users Association for Future Heterogeneous Telecommunication Access Infrastructures

In this paper an approach for resource management for Heterogeneous Networks (HetNets) based on the dynamic association of users in sets is proposed. The approach is based on the consideration that in a telecommunication network every access point has the property of limited performance, capacity and service potential. Through the definition of two generalized parameters of the servicing cell a characteristic model of the servicing properties of a HetNet access point is developed. An optimization task is defined for a resource management approach with the goal of “providing user service with the required quality of Service while minimizing servicing costs”. The task is solved via the introduction of a modified ADD/DROP heuristic algorithm. A comparison with two other heuristic algorithms is performed showing some of the advantages of the proposed algorithm such as its low computational complexity, fast convergence and effectiveness of the heuristic procedure. A sample application for transmission power control is presented.

Combined power and inter-cell interference control for LTE based on role game approach

In this paper the application of Role Game Theory to Power Control (PC) and Inter-Cell Interference Control (ICIC) for Long Term Evolution (LTE) is considered. The authors propose an approach based on defining different roles of the users within a cell of the LTE network. The main idea is to apply different methods and algorithms for PC and ICIC depending on the classified by role subscriber. Such an approach will give the possibility for flexible application and combination of different PC and ICIC methods for achieving better performance.

Non-intrusive sleep analyzer for real time detection of sleep anomalies

Solutions for caring for the elderly both efficacious and cost-effective are given by Ambient Assisted Living (AAL) systems that combine the research fields of intelligent systems and communication technologies. These systems are promising for the improvement of the quality of life of elderly and disabled people. One important characteristic of health and well-being is sleep. While sleep quantity is directly measurable, its quality has traditionally been assessed with subjective methods such as questionnaires. In this paper, we propose a non-intrusive sleep analyzer for real time detection of sleep anomalies, part of an effective AAL system. The proposed solution is based on combination of non-invasive sensors and an algorithm for sleep analysis with two stages - low and high level reasoning. It also offers the opportunity to include third party devices. Using the analyzer we can monitor basic sleep behavior and to detect sleep anomalies, which can serve as an important indicator for both mental and physical health.

Layered routing algorithm for sustainable MANET operation

In this paper a routing algorithm for MANETs is presented, based on the formation of servicing zones and determination of nodes in these zones as default gateways. The idea behind this approach is to gain power efficiency and sustainability of the network. The proposed approach reduces the overall number of broadcasts in the network and ensures a reliable and energy efficient connection, by balancing the load among the nodes. The algorithm could be considered as a hybrid type of routing mechanism, incorporating multipath hop-by-hop distributed routing. We apply a time slot based self-organizing and self-routing approach by the application of a network model with universal basic node properties. For each node we define two functional and one generic property. The algorithm has the logic of non-cooperative routing based on the evaluation of the defined basic properties of the nodes. The major advantages of the algorithm are related to the complexity and the reduced overall routing cost, especially in higher density networks.

Improved open loop power control for LTE uplink

In this paper an improved Open Loop Power Control (OLPC) approach for LTE is proposed. Using a heuristic classification procedure sets of User Equipments (UEs) with similar properties related to their distribution, location and the required throughput in the cell are formed. In addition a heuristic generic search algorithm is applied for the realization of a dynamic power allocation scheme giving an improvement of the overall cell throughput, based on the allocation of different path loss compensation factors to each UE set. The major advantages in applying this scenario is that OLPC is applied to sets of UEs with similar properties instead on single UEs and the proposed algorithms are based on heuristic classification and search methods requiring low computational complexity and giving fast outcomes. The results from the simulation experiments show that such an approach could be an effective solution for dynamic OLPC ensuring reduction of the inter-cell interference and average cell throughput closest to the maximum possible.

Multilayered Distributed Routing for Power Efficient MANET Performance

In this paper a new power efficient routing algorithm for MANETs with self-organizing and self-routing features is described and its performance analyzed in different simulation scenarios. The algorithm has the logic of a non-cooperative routing algorithm based on the evaluation of a weight parameter, the latter being a function of properties of the MANET nodes related to the nominal available power and the transmission range. A self-estimation of this weight parameter for each node is introduced in the routing process based on the status and functional history of the node. The routing is based on network layering, formation of service areas in each layer and choice of nodes from these areas to have the functionality of default gateways. The proposed algorithm, named service zone gateway prediction (SZGP), is a hybrid type of routing mechanism, incorporating pre-computed multipath hop-by-hop distributed routing, with a periodically updated hierarchical multilayered structure. The results from the simulation experiments show that the performance of the proposed SZGP algorithm in relation to the basic performance parameters such as packet delivery ratio, delay and throughput are similar to those of the well-known AODV algorithm, but in relation to power efficiency the proposed algorithm outperforms AODV significantly. This is due to the fact that such an approach reduces the overall number of broadcasts in the network and ensures a reliable and energy efficient connection by balancing the load among the nodes.

Autonomous learning model for achieving multi cell load balancing capabilities in HetNet

Heterogeneous networks (HetNets) have been proposed as a capacity and coverage enabler in LTE-Advanced and beyond communication networks. Their optimal operation requires a significant degree of self-organization. Autonomic Load Balancing (ALB) has been proposed as an important self-organizing (SON) function in the LTE radio access network (RAN). In this work, distributed ALB is achieved by implementing a programmable autonomous learning model. The optimization problem (load balancing) is split into many small optimization problems and tasks, which are solved by using machine learning algorithms. The load conditions of the E-UTRAN NodeB (eNBs) and the measurement reports from the mobile terminals are used for creating a decision map for the load balancing. The simulation results show that by using ALB, the system capacity can be improved significantly.

Interference limited Uplink Power Control based on a Cognitive Approach

In this paper a cognitive approach for Long Term Evolution (LTE) Uplink Power Control (UPC) based on Inter-Cell Interference (ICI) limitation is proposed. The goal of such an approach is maximum average cell throughput. The developed method is based on dividing the cell into zones with different uplink power settings based on a self learning neural classifier. The total uplink power for the different zones is chosen in such a way that the ICI does not exceed a predefined limit. By applying such a cognitive approach, a dynamic power control mechanism could be implemented depending on the distribution, location and the required throughput of the User Equipments (UEs) in the cell. Results from simulation experiments show that such an approach could be an effective solution for UPC in LTE.