Interference Awareness Research Articles

Path Planning Optimization Based Interference Awareness for Mobile Robots in mmWave Multi Cell Networks

Path Planning Optimization Based Interference Awareness for Mobile Robots in mmWave Multi Cell Networks

UAV Trajectory Planning With Interference Awareness in UAV-Enabled Time-Constrained Data Collection Systems

UAV Trajectory Planning With Interference Awareness in UAV-Enabled Time-Constrained Data Collection Systems

Interference-Aware Online Multicomponent Service Placement in Edge Cloud Networks and its AI Application

Edge computing that utilizes ubiquitous edge devices locating in close proximity to users is powerful for providing Quality of Service guaranteed computation offloading services. Toward the limited resources of edge servers and wireless links, large services can be split into multiple interconnected components to be served by multiple edge servers cooperatively. The current works on service placement either assume unsplittable services or ignore the geographically isolated property of edge servers. They also ignore the interference among online services that share the same physical nodes/links in terms of executing delay. Namely, every service adds load to the placed nodes/links and every increment on load of nodes/links risks delay violation of existing services. To overcome above challenges, this article emphasizes on the interference-aware (IA) online multicomponent service placement in edge cloud networks. First, the delay of tree-like services is analyzed considering the dependency among components, based on which the IA residual capacities of physical nodes, links, and paths are defined and formulated theoretically. Furthermore, we reduce the problem of multicomponent service placement to be NP-hard and transform it into an ant colony optimization (ACO) problem to obtain the near-optimal solution. More importantly, a level traversal component ranking method and an IA dynamic pruning method are proposed for ACO to achieve faster convergence, interference awareness, and higher acceptance ratio of services. Simulation results are presented to validate the effectiveness of proposed methods. In addition, the classic artificial intelligence application of image classification is experimented to further strength the motivation of IA investigation in practical.

Bluetooth Low Energy Interference Awareness Scheme and Improved Channel Selection Algorithm for Connection Robustness.

Bluetooth Low Energy (BLE) is a popular wireless communication protocol heavily used in Internet of Things applications. Nowadays, robustness is considered a key requirement in wireless communication. However, radio interference from various sources may affect the performance of BLE devices, leading to channel congestion. Therefore, there is a broadly recognized need of methodologies capable of sensing and avoiding interference. In this paper, two improvements at the data link layer for interference detection and channel selection are proposed to enhance the BLE connection robustness. This paper also presents a wide range of experimental evaluations aiming at validating the improvements and providing insights on both these improvements. Particularly, the communication performance of the BLE link layer is assessed in terms of channel usage distribution, supervision timeout ratio (STR) and packet loss rate (PLR) under different interference environments. Results from these experiments (reliability over 97% and 99% under two different harsh environments) highlight the effects of both improvements on the BLE robustness. Meanwhile, the authority of scheduling the whole mechanism is given to the link layer and even the higher application layer. This paper provides a set of solutions for BLE confronting interference in link layer.

A Simple and Efficient Way to Save Energy in Multihop Wireless Networks with Flow Aggregation

Today, whether in industry, research, or civil applications, there are many incentives to reduce the energy footprint of automated systems. In multihop wireless networks, the main objective in that regard is usually to maximize the lifetime of the network by distributing the load over all nodes. In this paper, we improve a solution that aggregates flows to optimize the number of nodes that can be turned off. We introduce interference awareness in a routing metric designed to aggregate flows to avoid overloading the network and to preserve the quality of service required by the flows. This way, it becomes possible to integrate this metric into classical shortest path routing algorithms that do not consider interference. We also show that flow aggregation and overall energy consumption are equivalent problems.

IPBM: an energy efficient reliable interference-aware periodic broadcast messaging protocol for MANETs

Mobile ad-hoc networks (MANETs) have been widely employed in many fields including critical information delivery in open terrains as in tactical area, vehicular or disaster area network scenarios. To provide effective network maintenance for those MANETs, it is essential to adopt proper control communication methods, which provide reliable delivery of network information. However, it is difficult to provide control communication that meets the quality of service requirements due to the broadcasting of control messages and dynamic nature of MANETs. Interference is one of the major problems that degrades this service quality, especially for the networks deployed in open terrain environments. Moreover, large and dense MANET scenarios further complicate this problem. Even though many communication methods have been proposed in the literature, a satisfactory one for periodic and broadcast delivery of control packets considering the interference awareness and at the same time yielding high reliability, goodput, energy efficiency still does not exist for MANETs. To that end, we present a new control communication protocol, which is referred to as the Interference-Aware Periodic Broadcast Messaging (IPBM) protocol, for those MANETs deployed in interference-rich open terrains. We show that the proposed interference awareness mechanism of IPBM, in which the transmission power of the units is increased at certain periods, significantly reduces the packet loss caused by the interference problem. Moreover, IPBM achieves an important amount of increase in the link reliability as well as in goodput with the least power consumption among the evaluated solutions. The mobility support feature of IPBM makes the protocol applicable not only to large and dense but also to highly dynamic MANETs. Besides, IPBM can properly work alongside the deployed main data communication protocol, since it provides valuable network information to be manipulated. Simulation results under both static and dynamic topologies confirm that adopting the IPBM protocol in the intended MANET scenarios significantly increases the reliability and goodput as well as the energy efficiency.

MIMO Cellular Networks Performance Under User-Assisted Relaying

We design user-assisted relaying strategies and analyze their performance in a multiple-input-multiple-output uplink cellular network. In user-assisted relaying, the base station serves an active user equipment (UE) using a transmission scheme adaptive between direct transmission and relaying via another UE according to a cooperation strategy. Modeling the network based on stochastic geometry and Poisson point processes, we propose a practical, geometric-based cooperation strategy determining how to select the relaying UE and when to perform relaying transmission. The proposed relaying transmission employs a simple transmit beamforming and one of two optimized receive combining schemes depending on interference awareness. The extra interference generated by relaying UEs is captured in an interference model that accounts for the adaptive transmission and random locations of these UEs. Integrating the proposed cooperation strategy, transmit and receive beamforming design, and interference model, we analyze the network outage rate performance. Provided sufficient density of potential relay UEs, results demonstrate user-assisted relaying to be most beneficial for cell edge UEs when the relaying UEs are equipped with multiple antenna elements and their signals propagate in relatively high shadowing environments.

Interference Aware, Topology, Power and Flow Control Channel Assignment Algorithm for Multi-Radio Multi-Channel Wireless Mesh Networks

Interference Aware, Topology, Power and Flow Control Channel Assignment Algorithm for Multi-Radio Multi-Channel Wireless Mesh Networks

Hybrid Access Femtocells in Overlaid MIMO Cellular Networks With Transmit Selection Under Poisson Field Interference

This paper analyzes the performance of hybrid control-access schemes for small cells (such as femtocells) in the context of two-tier overlaid cellular networks. The proposed hybrid access schemes allow for sharing the same downlink resources between the small-cell network and the original macrocell network, and their mode of operations are characterized considering post-processed signal-to-interference-plus-noise ratios (SINRs) or preprocessed interference-aware operation. This paper presents a detailed treatment of achieved performance of a desired user that benefits from MIMO arrays configuration through the use of transmit antenna selection (TAS) and maximal ratio combining (MRC) in the presence of Poisson field interference processes on spatial links. Furthermore, based on the interference awareness at the desired user, two TAS approaches are treated, which are the signal-to-noise-based selection and SINR-based selection. The analysis is generalized to address the cases of highly-correlated and un-correlated aggregated interference on different transmit channels. In addition, the effect of delayed TAS due to imperfect feedback and the impact of arbitrary TAS processing are investigated. The analytical results are validated by simulations, to clarify some of the main outcomes herein.

Energy-Efficient Routing Protocol based on Interference Awareness for Transmission of Delay-Sensitive Data in Multi-Hop RF Energy Harvesting Networks

Energy-Efficient Routing Protocol based on Interference Awareness for Transmission of Delay-Sensitive Data in Multi-Hop RF Energy Harvesting Networks

Virtual Machine Scheduling Model Based on Energy and Interference Awareness in Cloud Environment

Virtual Machine Scheduling Model Based on Energy and Interference Awareness in Cloud Environment

Analytical Modeling of Interference Aware Power Control for the Uplink of Heterogeneous Cellular Networks

Inter-cell interference is one of the main limiting factors in current Heterogeneous Cellular Networks (HCNs). Uplink Fractional Power Control (FPC) is a well known method that aims to cope with such limiting factor as well as to save battery live. In order to do that, the path losses associated with Mobile Terminal (MT) transmissions are partially compensated so that a lower interference is leaked towards neighboring cells. Classical FPC techniques only consider a set of parameters that depends on the own MT transmission, like desired received power at the Base Station (BS) or the path loss between the MT and its serving BS, among others. Contrary to classical FPC, in this paper we use stochastic geometry to analyze a power control mechanism that keeps the interference generated by each MT under a given threshold. We also consider a maximum transmitted power and a partial compensation of the path loss. Interestingly, our analysis reveals that such Interference Aware (IA) method can reduce the average power consumption and increase the average spectral efficiency. Additionally, the variance of the interference is reduced, thus improving the performance of Adaptive Modulation and Coding (AMC) since the interference can be better estimated at the MT.

Near-Optimal Beam Selection for Beamspace MmWave Massive MIMO Systems

The recent concept of beamspace MIMO can utilize beam selection to reduce the number of required radio-frequency (RF) chains in mmWave massive MIMO systems without obvious performance loss. However, as the same beam in the beamspace is likely to be selected for different users, conventional beam selection schemes will suffer from serious multiuser interferences, and some RF chains may be wasted since they have no contribution to the sum-rate performance. To solve these problems, in this letter, we propose an interference-aware (IA) beam selection. Specifically, by considering the potential multiuser interferences, the proposed IA beam selection first classifies all users into two user groups, i.e., the interference-users (IUs) and noninterference-users (NIUs). For NIUs, the beams with large power are selected, while for IUs, the appropriate beams are selected by a low-complexity incremental algorithm based on the criterion of sum-rate maximization. Simulation results verify that IA beam selection can achieve the near-optimal sum-rate performance and higher energy efficiency than conventional schemes.

Analysis of Joint Transmit–Receive Diversity in Downlink MIMO Heterogeneous Cellular Networks

We study multiple-input–multiple-output (MIMO)-based downlink heterogeneous cellular networks (HetNets) with joint transmit–receive diversity using orthogonal space–time block coding at the base stations (BSs) and maximal-ratio combining (MRC) at the users. MIMO diversity with MRC receivers is particularly appealing in cellular networks due to the relatively low hardware complexity at both the BS and the user device. Using stochastic geometry, we develop a tractable stochastic model for analyzing such HetNets taking into account the irregular and multitier BS deployment. We derive the coverage probability for both interference-blind (IB) and interference-aware (IA) MRC as a function of the relevant tier-specific system parameters such as BS density and transmit (Tx) power, number of Tx antennas, and path-loss law. Important insights arising from our analysis for typical HetNets are as follows: 1) IA-MRC becomes less favorable than IB-MRC with Tx diversity due to the smaller interference variance and increased interference correlation across receive (Rx) antennas; 2) ignoring spatial interference correlation significantly overestimates the performance of IA-MRC; and 3) for a small number of Rx antennas, selection combining may offer a better performance–complexity tradeoff than MRC.

셀룰러 네트워크에서 간섭 인지 기반의 단말간 직접 통신 자원할당 방법

셀룰러 네트워크에서 간섭 인지 기반의 단말간 직접 통신 자원할당 방법

Flexible UL-DL Switching Point in TDD Cellular Local Area Wireless Networks

An advantage of time division duplex (TDD) wireless networks over frequency division duplex (FDD) is that the UL-DL switching point may be flexibly adapted to asymmetric traffic loads. This enables more efficient spectrum use, but on the other hand may lead to harmful cross-link interference between cells. As a result, the net gain (or loss) from flexible TDD depends on the traffic characteristics and network scenario. In this paper we address the problem in local area packet data networks, such as small- or femto-cell network, where high fluctuation in short term traffic loads is expected. We show through analysis and system level simulations that in such a scenario a significant gain in effective user throughput and packet delays may be achieved under low traffic loads. At high load the gain becomes smaller as packets accumulate in queues and there is both UL and DL traffic to transmit with high probability. When the UL and DL transmit powers are not balanced and switching point adaptation is applied the link direction with lower power may provide degraded performance. We show that introducing interference awareness at the scheduler provides more balanced performance and lowers the packet delays further.

무선 센서 네트워크를 위한 간섭 인지 기반의 결함 허용 QoS 라우팅 기법

본 논문에서는 무선 센서 네트워크에서 실시간 대용량 데이터를 전송하고자 할 때 QoS 요구조건과 에너지 효율성 요구를 만족시킬 수 있는 간섭 인지 기반의 결함 허용 QoS 라우팅 기법을 제안한다. 제안된 기법에서는 처리량을 최대화하고 지연시간을 최소화하기 위해 간섭비율과 예측전송시간을 기반으로 하는 새로운 누적 경로 메트릭을 사용하여 전송 경로에 결함이 발생하더라도 최적의 전송경로를 결정하도록 한다. 마지막으로, 시뮬레이션을 통하여 제안된 라우팅 기법을 사용하면 네트워크 처리량 및 지연시간 측면에서 성능이 향상됨을 보인다. In this paper, we propose a fault-tolerant QoS routing scheme based on interference awareness for providing both high throughput and minimum end-to-end delay for wireless sensor networks. With the proposed algorithm, it is feasible to find out the optimal transmission path between sensor nodes to the sink node by using cumulative path metric where real-time delivery, high energy efficiency and less interference are considered as in path selection. Finally, simulation results show that network throughput and delay can be improved by using the proposed routing scheme.

MU-MIMO in LTE Systems

A relatively recent idea of extending the benefits of MIMO systems to multiuser scenarios seems promising in the context of achieving high data rates envisioned for future cellular standards after 3G (3rd Generation). Although substantial research has been done on the theoretical front, recent focus is on making Multiuser Multiple-Input Multiple-Output (MUMIMO) practically realizable. This paper presents an overview of the different MU-MIMO schemes included/being studied in 3GPP standardization from LTE (long-term evolution) to LTE Advanced. MU-MIMO system concepts and implementation aspects have been studied here. Various low-complexity receiver architectures are investigated, and their performance assessed through link-level simulations. Appealing performance offered by low-complexity interference aware (IA) receivers is notably emphasized. Furthermore, system level simulations for LTE Release 8 are provided. Interestingly, it is shown that MU-MIMO only offers marginal performance gains with respect to single-user MIMO. This arises from the limited MU-MIMO features included in Release 8 and calls for improved schemes for the upcoming releases.

The Natural Personality Enhancement Model: A Program for the Management of Conduct Disordered Children

ABSTRACT This article presents Webster's Natural Personality Enhancement (N.P.E.) Model, and describes the theoretical framework with reference to the development of a residential treatment home for conduct disordered adolescents. N.P.E. is a two-stage therapeutic program which includes clearly-defined psychological principles and treatment techniques. Stage One of the N.P.E. Model, “Creating a safe environment,” involves the following seven components: respect, expectations, the consequence of no consequences, confusion, interference, tolerance, and emotional awareness training (E.A.T.). Stage Two of the Model, the intervention techniques, explains the four-phase treatment process, including the concepts of suggestibility and love language. This therapeutic program appears to produce sufficient environmental stability to meet the intense and varied needs of children with conduct disorder tendencies.