University of Vigo

TitleVigo Uni

BestNet: SDN enabled converged network optimization.


University of Vigo


Carlos Pérez-Garrido, Felipe Gil-Castiñeira, Francisco J. González-Castaño, Pablo Pousada-Rial and Abel Fernández-Nadín.

3rd Party Hardware and Software used

  • Lime Microsystems SDR.
  • OpenAirInterface eNB and EPC.
  • OpenDayLight

Current State

This PoC shows a SDN-enabled terminal (a computer) that is commanded to switch between two SDN Wireless Access Points without losing session continuity, or even to use both interfaces simultaneously. LTE (implemented with OAI eNB and EPC, and LimeSDR) supports control data exchange and user data transmission while the Wi-Fi interface is down or is reconnecting.


Smartphones and tablets have nowadays several wireless access technologies available. Nevertheless, terminals are not managed by the network, and they have been considered just as leaf nodes with a single network interface.

Users and operators are using Wi-Fi to offload cellular connections, especially in areas with high connectivity demand. In addition, small cells and other ultra-dense networks will be essential to reach the expected data rates for 5G.

Nevertheless, current solutions to manage different terminals just configure terminals to connect to a list of Wi-Fi APs. Therefore, there is potential demand for solutions to maintain connectivity (at the application level) and select the best network interface according to a set of performance metrics (lowest latency, highest bandwidth, lower consumption, etc.).

Network operators have enough information to determine and predict the "best interface" and the "best network" that should be used at every moment. Currently, it is not possible to command devices to use one or another. However, by transforming them into SDN routers managed by the network, this will not only be feasible, but it will also be possible to alter routes without interrupting applications.

In this PoC demo, we show how a LTE network (in the future, a 5G network) can be optimized by allowing it to handle the connections of a user terminal. A USPTO patent has been granted covering this approach (publication number US20170093722 A1).

To achieve this objective we include SDN agents in users' terminals. They are connected to a SDN controller that centralizes some decisions that to date, were user centric, such as access network selection and traffic steering through multiple interfaces.

This way, the “Network” can decide the best interface and access network at each moment to satisfy users' needs and optimize network performance. Hence, it is possible to reach the required latency or bandwidth (or, in general terms, the expected QoE), even on the move or when the state of the network changes dynamically.


Video: BestNet Video

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