Wi-5 has developed and implemented a range of smart and cooperative solutions that were integrated into the Wi-5 architecture, which takes into account the requirements for new business roles to support Wi-5 operations and the use cases we envision. These roles will not only facilitate Intra-Operator Cooperation on the spectrum plane, but will also enable Inter-Operator Cooperation on the business plane. We have validated this approach through simulation and modelling, and extensive interaction with a group of network operators and other stakeholders.
As part of the integrated Wi-5 solution, a novel set of functionalities have been developed that address the lack of flexibility in the management and utilisation of IEEE 802.11 WLANs, which are not inherently cooperative in nature. These functionalities include the following notable features:
1. Radio Resource Management (RRM) to address interference in Wi-Fi networks by combining both AP channel assignment and transmit power adjustment techniques. Our approach improves the application flow Quality of Service (QoS) through transmit power control, while at the same time considering the effect of the Radio Frequency (RF) channels configuration on the rest of the network. Our RRM algorithm was compared against existing approaches and our results show that it performs better than the state of the art in terms of interference, Signal to Interference plus Noise Ratio (SINR), spectrum efficiency and users satisfaction.
2. Smart AP selection, which associates users to Wi-Fi APs based on an innovative performance and QoS evaluation metric called Network Fittingness Factor (FF), efficiently addresses the QoS requirements of both a flow joining the network and other flows active in the network. This was extended in later versions to introduce a centralised potential game which provides better performance. We compared our solution against existing approaches found in the literature, demonstrating that our strategy performs better than the state of the art in terms of users’ satisfaction, blocking probability and Quality of Experience (QoE).
3. Vertical Handover algorithm that extends our AP Selection algorithm to select the most suitable connection between Wi-Fi APs and 3G/4G Base Stations (BSs) for each new user/flow running in a dual-interface device, such as a smartphone or a tablet.
4. Centrally coordinated packet grouping which aggregates small packets based on existing 802.11 standards but considers the trade-off between efficiency and latency based on the user requirements. Our approach also considers how this can be intelligently applied in a managed wireless network. Our results show significant efficiency savings can be introduced with little or no impact on the user’s perceived performance.
We have integrated the above features into a prototype real-time SDN platform based on Odin. Specifically, the smart AP monitoring, channel selection, and seamless handover functionalities have been employed to drive the channel assignment and AP selection algorithms and the seamless handover functionality has also been integrated as part of the load balancing functionality. This proof of concept implementation has been developed as an open source project (
https://github.com/Wi5/(öffnet in neuem Fenster)) and we have rigorously tested and improved the system as part of our work. This includes extensive testing in a test house lab environment and a number of real world deployments and user trials.
Wi-5 had an extensive plan to maximize our impact through scientific dissemination, industrial exploitation, and standardization. From 2015 to 2018 we have written and published over 10 high quality journal papers and presented a similar number of papers at a number of well-respected international conferences. In addition, Wi-5 has submitted a number of contributions to standardisation bodies including the IETF, HGI, and BBF. Finally, each member of the consortium is committed to pursuing a range of exploitation options in their respective markets and are actively attempting to engage external partners to further exploit the results. In addition, Wi-5 engaged effectively with industry through our Operator Board which provided periodic input and feedback to better tune our work to the needs of the market.
