SDN-Based Channel Assignment Algorithm for Interference Management in Dense Wi-Fi Networks

The popularity of Wi-Fi-enabled devices alongside the growing demand for non-licensed spectrum, has made the Wi-Fi networks exceedingly congested. This endangers the efficiency of Wi-Fi and negatively affect the users' experience. The problem is especially pressing in dense areas (e.g. shopping centers) where Wi-Fi channel assignment is more likely to be uncoordinated and the working environment of Wi-Fi Access Points (APs) has become increasingly time-variant. As a result, the availability of Software-Defined Networking (SDN) and network virtualization technologies has motivated the use of centralized resource management as a solution. This paper provides an algorithm for channel assignment functionality in the context of SDN-based centralized resource management, which captures the live status of a Wi-Fi network and is capable of optimising the Radio Frequency (RF) channel assignment process. The APs' network arrangement, the current assignment of the channels and the characteristics of the RF channels in IEEE 802.11 have all been taken into account in the proposed model. The performance of the proposed model in terms of the level of the interference, the spectral efficiency at each AP and the Signal to Interference plus Noise Ratio (SINR) at the user-side is evaluated through simulation and compared against state of the art solutions

Fine-Grained Radio Resource Management to Control Interference in Dense Wi-Fi Networks

In spite of the enormous popularity of Wi-Fienabled devices, the utilization of Wi-Fi radio resources (e.g. RF spectrum and transmission power levels) at Access Points (APs) is degraded in current decentralized Radio Resource Management (RRM) schemes. Most state of the art central control solutions apply configurations in which the network-wide impacts of the involved parameters and their mutual relationships are ignored. In this paper, we propose an algorithm for jointly adjusting the transmission power levels and optimizing the RF channel assignment of APs by taking into account the flows’ required qualities while minimizing their interference impacts throughout the network. The proposed solution is tailored for an operatoragnostic and Software Defined Wireless Networking (SDWN)- based centralised RRM in dense Wi-Fi networks. Our extensive simulation results validate the performance improvement of the proposed algorithm compared to the main state of the art alternative by showing more than 25% higher spectrum efficiency, satisfying the users’ demands and further mitigating the networkwide interference through a flow-based and quality-oriented power level adjustment

SDN-based channel assignment algorithm for interference management in dense Wi-Fi networks

The popularity of Wi-Fi-enabled devices alongside the growing demand for non-licensed spectrum, has made the Wi-Fi networks exceedingly congested. This endangers the efficiency of Wi-Fi and negatively affect the users' experience. The problem is especially pressing in dense areas (e.g. shopping centers) where Wi-Fi channel assignment is more likely to be uncoordinated and the working environment of Wi-Fi Access Points (APs) has become increasingly time-variant. As a result, the availability of Software-Defined Networking (SDN) and network virtualization technologies has motivated the use of centralized resource management as a solution. This paper provides an algorithm for channel assignment functionality in the context of SDN-based centralized resource management, which captures the live status of a Wi-Fi network and is capable of optimising the Radio Frequency (RF) channel assignment process. The APs' network arrangement, the current assignment of the channels and the characteristics of the RF channels in IEEE 802.11 have all been taken into account in the proposed model. The performance of the proposed model in terms of the level of the interference, the spectral efficiency at each AP and the Signal to Interference plus Noise Ratio (SINR) at the user-side is evaluated through simulation and compared against state of the art solutions

Fine-Grained Radio Resource Management to Control Interference in Dense Wi-Fi Networks

In spite of the enormous popularity of Wi-Fienabled devices, the utilisation of Wi-Fi radio resources (e.g. RF spectrum and transmission power levels) at Access Points (APs) is degraded in current decentralised Radio Resource Management (RRM) schemes. Most state of the art centralised control solutions apply configurations in which the network-wide impacts of the involved parameters and their mutual relationships are ignored. In this paper, we propose an algorithm for jointly adjusting the transmission power levels and optimising the RF channel assignment of APs by taking into account the flows’ required qualities while minimising their interference impact throughout the network. The proposed solution is tailored for an operatoragnostic and Software Defined Wireless Networking (SDWN)- based centralised RRM in dense Wi-Fi networks. Our extensive simulation results validate the performance improvements of the proposed algorithm compared to the main state of the art alternative by showing more than 25% higher spectrum efficiency, satisfying the users’ demands and further mitigating the networkwide interference through flow-based and quality-oriented power level adjustment

Specification of Cooperative Access Points Functionalities version 1

The What to do With the Wi-Fi Wild West H2020 project (Wi-5) combines research and innovation to propose an architecture based on an integrated and coordinated set of smart Wi-Fi networking solutions. The resulting system will be able to efficiently reduce interference between neighbouring Access Points (APs) and provide optimised connectivity for new and emerging services. The project approach is expected to develop and incorporate a variety of different solutions, which will be made available through academic publications, in addition to other dissemination channels. The present document includes the specification of the first version of the Cooperative AP Functionalities, which are being defined within Work Package (WP) 4 of the Wi-5 project. In this deliverable after the Executive Summary and the literature review, the first version of the Cooperative Access Point Solutions are illustrated. In particular, a section with a general cooperative framework that jointly includes functionalities for an optimized AP channel assignment, Radio Resource Management (RRM) and smart AP allocation is presented. The optimized APs channel assignment enables an important improvement of the network performance in terms of SINR. Furthermore, the results analysed in this deliverable validate the flexibility and practicality of the proposed algorithm in different scenarios. The smart AP allocation solution introduces the innovative Fittingness Factor (FF) concept that efficiently matches the suitability of the available spectrum resource to the application requirements. Moreover, the basis required for a seamless mobility functionality in the framework is also included in the section. Next, a first assessment of the algorithms proposed in this deliverable is presented through the analysis of several performance results in a simulated environment. In detail, the AP channel assignment and the smart AP allocation algorithms are assessed and compared against other strategies found in the literature. Finally, a set of monitoring procedures to be conducted on the Wi-5 APs and on the Wi-5 controller are presented. These procedures will allow the correct deployment of the cooperative APs functionalities proposed in this deliverable. After summarising the main conclusions, the document ends with future work

Specification of Cooperative Access Points Functionalities version 2

The What to do With the Wi-Fi Wild West H2020 project (Wi-5) combines research and innovation to propose an architecture based on an integrated and coordinated set of smart Wi-Fi networking solutions. The resulting system will be able to efficiently reduce interference between neighbouring Access Points (APs) and provide optimised connectivity for new and emerging services. The project approach is expected to develop and incorporate a variety of different solutions, which will be made available through academic publications, in addition to other dissemination channels. This deliverable presents the specification of the second version of the Cooperative AP Functionalities that are being designed in the context of Work Package (WP) 4 of the Wi-5 project. Specifically, we present a general cooperative framework that includes functionalities for a Radio Resource Management (RRM) algorithm, which provides channel assignment and transmit power adjustment strategies, an AP selection policy, and a solution for vertical handover. The RRM achieves an important improvement for network performance in terms of several parameters through the channel assignment approach, that can be further improved by including the transmit power adjustment. The AP selection solution extends the approach presented in deliverable D4.1 based on the Fittingness Factor (FF) concept, which is a parameter for efficiently matching the suitability of the available spectrum resource to the application requirements. Moreover, the preliminary details, which will allow us to extend AP selection towards vertical handover functionality including 3G/4G networks, are also presented. The assessment of the algorithms proposed in this deliverable is illustrated through the analysis of several performance results in a simulated environment against other strategies found in the literature. Finally, a set of monitoring capabilities implemented on the Wi-5 APs and on the Wi-5 controller are illustrated. These capabilities will enable the correct deployment of the cooperative APs functionalities proposed in this deliverable in realistic scenarios

Final Specification of Cooperative Functionalities

This deliverable presents the specification of the final version of the Cooperative AP Functionalities that have been designed in the context of Work Package (WP) 4 of the Wi-5 project. In detail, we present a general cooperative framework that includes functionalities for a Radio Resource Management (RRM) algorithm, which provides channel assignment and transmit power adjustment strategies, an AP selection policy, which also provides horizontal handover, and a Radio Access Technology (RAT) selection solution for vertical handover. The RRM algorithm achieves an important improvement for network performance in terms of several parameters through the channel assignment approach and the transmit power adjustment. The AP selection solution extends the approach presented in deliverables D4.1 and D4.2 and is based on a centralised potential game, which optimises the distribution of the so-called Fittingness Factor (FF) parameter among the Wi-Fi users. Such a parameter efficiently matches the suitability of the available spectrum resource to the users’ application requirements. Moreover, the RAT selection solution extends the AP selection algorithm towards vertical handover functionality including 3G/4G networks. The assessment of the newest algorithms developed in the context of WP4 is illustrated in this deliverable through the analysis of several performance results in a simulated environment against other strategies found in the literature. Finally, the set of smart AP functionalities developed in the context of WP3, implemented on the Wi5 APs and on the Wi-5 controller, and their use in the proposed algorithms are illustrated. Specifically, this deliverable describes how these functionalities can enable the correct deployment of the proposed cooperative AP solutions in realistic scenarios. Therefore, the main novel contributions of this deliverable are i) the strengthening of the AP selection algorithm, ii) the design and assessment of a new algorithm for vertical handover and iii) the presentation of the finalised integration of the cooperative AP functionalities of the Wi-5 system

Specification of Smart AP solutions - version 2

This document includes the specification of the second version of the Smart Access Point (AP) Solutions, which are being developed within WP3 of the Wi-5 project. After the Literature Review, a global view of the Wi-5 architecture is presented which includes not only the Smart AP Solutions but also the Cooperative Functionalities being developed in WP4. Next, the Smart AP Solutions are described including the summary of the general approach being followed based on Light Virtual APs (LVAPs). The functionalities enabling Radio Resource Management (i.e. Dynamic Channel Allocation, Load Balancing and Power Control) are reported in detail and the current status of the implementation of the solutions is detailed, with a set of improvements aimed at integrating the support of different channels within the Wi-5 framework. A multi-channel handoff scheme has been designed, requiring a good synchronisation between the different events, in order to make the LVAP switching happen at the same moment when the STA switches its channel. In addition, the beacon generation has been modified in order to improve the scalability and to give a better user experience during handoffs. Tests measuring the handoff delay are presented using three wireless cards from different manufacturers, and using as test traffic a flow of an online game with real-time constraints. The results show that fast handovers ranging from 30 to 200 milliseconds can be achieved. The savings provided by frame aggregation, and its effect on subjective quality have also been studied. A methodology including subjective tests with real users has evaluated this effect, using paired comparison. The results indicate that bandwidth usage savings and especially significant packet rate reduction can be obtained without degrading players’ Quality of Experience (QoE), as long as the overall latency is kept under 100ms. An important finding coming from these results is that the players do not register delay variation introduced by multiplexing