Presented at the Global Access to the Internet for All (GAIA) Research Group Meeting, at IETF-96, Berlin, Germany, July 21, 2016. The Wi-5 Project (What to do With the Wi-Fi Wild West) proposes an architecture based on an integrated and coordinated set of smart Wi-Fi APs: a) To efficiently reduce interference between neighboring Wi-Fi APs and provide optimized connectivity. b) To develop new business models to support this. An open-source and low cost platform supporting advanced features currently available in enterprise-grade Wi-Fi APs: - Optimal frequency planning - Load balancing - Seamless handover - Transmit power control - Intelligent frame/packet grouping - Interference measurement

1. Wi-5: Advanced Features for Low-cost
Wi-Fi APs
GAIA RG Meeting @ IETF-96
Berlin, Germany
July 21, 2016
Jose Saldana, Julián Fernández-Navajas (University of Zaragoza)
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 1

2. Objectives of the Project
The Wi-5 Project (What to do With the Wi-Fi Wild West)
proposes an architecture based on an integrated and
coordinated set of smart Wi-Fi APs:
• To efficiently reduce interference between neighboring
Wi-Fi APs and provide optimized connectivity.
• To develop new business models to support this.
Solutions must be able to run:
• On the operator’s APs (low cost).
• On top of the existing PHY and MAC Wi-Fi layers (no
modifications to 802.11 are considered).
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 2

3. Use cases
• Airport/train station
• Dense apartment building
• Pico-cell street deployment
• Large home/SOHO: multiple
APs in the same property
• Community Wi-Fi: Creating
2 SSIDs and 2 VLANs, one
private and one public
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 3
Gateway
AP
AP

4. Solutions being developed
Shared in https://github.com/Wi5
Objective: An open-source and low cost platform
supporting advanced features currently available in
enterprise-grade Wi-Fi APs:
• Optimal frequency planning
• Load balancing
• Seamless handover
• Transmit power control
• Intelligent frame/packet grouping
• Interference measurement
The solutions must be scalable.
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 4

5. Concept of Light Virtual Access Point (LVAP)
• A central controller (an OpenFlow SDN
controller) creates an LVAP (Light Virtual
AP) for each terminal, which is
dynamically assigned to the physical AP
where the terminal is located at each
moment.
• The AP will use a different LVAP (which
includes a specific MAC) for
communicating with each terminal.
• The terminal will only “see” a single AP,
even if it is actually moving between a
number of them, thus avoiding the
need for re-association.
• Odin* is being extended.
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 5
Client 2
2
Client 2
LVAP2LVAP2
1
Controller
LVAP1
Client 1
* J. Schulz-Zander, L. Suresh, N. Sarrar, A. Feldmann, T. Hühn, R. Merz, “Programmatic orchestration of wifi networks,” in USENIX
Annual Technical Conference (USENIX ATC 14), pp. 347-358, Jun 2014.

6. Example: Seamless Handoff
A reactive application that manages
the handover of a STA (Station),
when the user is moving.
• The origin AP detects the
movement and reports it to the
controller (2)
• The controller sends a scan
request to the destination AP (3)
• The controller makes a decision,
and moves the STA to the
destination AP (7 and 8).
• The STA only “sees” a channel
switch, not a re-association. It
only takes 20-100 ms.
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 6
STA
Channel
A
Channel
B
CSA
7
3
STA
LVAPLVAP
2
PUBLISH
5 Resource
management
algorithm
STA Switch
to channel B
Add LVAP
1
4
Scan
response
Remove
LVAP
6
Scan
request
8
Send
CSA
8
8
AP1 AP2
Burst of
beacons

7. Seamless Handoff results
Two machines are generating traffic of a real-time online game.
The delay mainly corresponds to the wireless technology, and does not significantly
increase around the handoff (numbers in red are the number of packets lost in a handoff).
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 7
Delay of Quake 3 packets when no background traffic is present. Beacon interval 10ms

8. THANK YOU VERY MUCH
http://www.wi5.eu/ https://github.com/Wi5
15/07/2016 Wi-5 Project, http://www.wi5.eu/ 8
European Union
Horizon 2020
This work has been partially financed by the EU H2020 Wi-5 project (G.A. no: 644262), and the Spanish Ministry of Economy
and Competitiveness project TIN2015-64770-R, in cooperation with the European Regional Development Fund.