LTE Femtocells are designed to increase capacity and coverage especially for the indoor and cell-edge mobile users. Typically, they are deployed to offload the macrocell users. However, due to co-location of femtocells in macrocell coverage, the co-tier and cross-tier interferences are high. The interference levels are different for each femtocell access mode. In this paper, we conduct experiment and study the network performance of LTE network with femtocells operating in three access modes. We define network productivity which measures the network performance based on reward associated with new call arrivals and penalty accounted for forced termination due to handoff failure. We conclude with specific parameter setup for reward and penalty weights for each network deployment and determine the desired network performance for each femtocell deployment.
LTE Femtocells are designed to increase capacity and coverage especially for the indoor and cell-edge mobile users. Typically, they are deployed to offload the macrocell. However, due to co-location of femtocells in macrocell coverage, the co-tier and cross-tier interferences are high. Fractional Frequency Reuse mechanism (FFR) is one of the most effective femtocell interference avoidance techniques. In this paper, we propose a new metric to determine optimal inner region radius and frequency allocation which optimizes the total cell throughput and serves as many number of users in the network. We already know that FFR technique is designed to better serve cell edge users. With introduction of new metric, we extend that idea to serve as many users in the network. The new metric is applied to sectorized FFR configurations and their performance is evaluated under different network conditions.
LTE networks are deployed to increase capacity and coverage especially for the indoor and cell-edge mobile users. However, such deployment comes with major challenges, radio resource management and inter-cell interferences. Fractional Frequency Reuse mechanism (FFR) is one of the most effective interference avoidance techniques. In this paper, we evaluate an existing adaptation process that adjusts to better network performance as users move in the network. With adaptation in place, we utilize our proposed metric to determine inner region radius and frequency allocation which generates high total cell throughput and serves maximum number of users in the network. The performance of static sectorized FFR with specific mobility model using adaptation process is evaluated using proposed metric and other metrics.
Mobile broadband has gained momentum with the growing demand of user data rates.Long Term Evolution (LTE) technology is the step in mobile communications evolution, developed to satisfy high data rate demand, and meet better spectral efficiency requirements.Effective radio resource management and inter cell interferences are the major challenges.Fractional Frequency Reuse (FFR) is one of the effective interference avoidance mechanisms applied to LTE networks to yield optimal throughput.In this extended paper, we propose a novel performance metric, weighted throughput on user satisfaction, and evaluate an existing adaptation process that dynamically adjusts to optimal network performance determined by FFR mechanism with mobile users.The performance of FFR mechanism with mobility model, adaptation process, and femtocell densification is evaluated and optimized for proposed metric and other metrics.Results optimized by proposed metric show comparatively higher average throughput and lower variance among user throughput.
Long Term Evolution (LTE) femtocells operate in three access modes based on subcarriers allocated to guaranteed and non-guaranteed users. In this paper, we conduct simulations and study the LTE network performance with femtocells. We define network productivity which measures the network performance based on reward associated with new call arrival and penalty accounted for forced call termination due to handoff failure. Using specific parameter setup for reward and penalty weights for each network deployment from previous simulations, we present the effects of call mobility on subcarrier allocation for each femtocell deployment. We also determine the subcarrier allocation reserved for guaranteed users that yields maximum network throughput for a given blocking probability vector.
The demand for higher data rates for indoor and cell-edge users led to evolution of small cells. LTE femtocells, one of the small cell categories, are low-power low-cost mobile base stations, which are deployed within the coverage area of the traditional macro base station. The cross-tier and co-tier interferences occur only when the macrocell and femtocell share the same frequency channels. Open access (OSG), closed access (CSG), and hybrid access are the three existing access-control methods that decide users' connectivity to the femtocell access point (FAP). We define a network performance function, network productivity, to measure the traffic that is carried successfully. In this dissertation, we evaluate call mobility in LTE integrated network and determine optimized network productivity with variable call arrival rate in given LTE deployment with femtocell access modes (OSG, CSG, HYBRID) for a given call blocking vector. The solution to the optimization is maximum network productivity and call arrival rates for all cells. In the second scenario, we evaluate call mobility in LTE integrated network with increasing femtocells and maximize network productivity with variable femtocells distribution per macrocell with constant call arrival rate in uniform LTE deployment with femtocell access modes (OSG, CSG, HYBRID) for a given call blocking vector. The solution to the optimization is maximum network productivity and call arrival rates for all cells for network deployment where peak productivity is identified. We analyze the effects of call mobility on network productivity by simulating low, high, and no mobility scenarios and study the impact based on offered load, handover traffic and blocking probabilities. Finally, we evaluate and optimize performance of fractional frequency reuse (FFR) mechanism and study the impact of proposed metric weighted user satisfaction with sectorized FFR configuration.
Wireless sensor networks are battery-powered ad-hoc networks in which sensor nodes that are scattered over a region connect to each other and form multi-hop networks. These nodes are equipped with sensors such as temperature sensors, pressure sensors, and light sensors and can be queried to get the corresponding values for analysis. However, since they are battery operated, care has to be taken so that these nodes use energy efficiently. One of the areas in sensor networks where an energy analysis can be done is routing. This work explores grid-based coordinated routing in wireless sensor networks and compares the energy available in the network over time for different grid sizes.
