C3Subtitles: 32c3: All Our Shared Spectrum Are Belong to Us
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All Our Shared Spectrum Are Belong to Us

Visualizing WLAN Channel Usage on OpenWRT

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Video duration
00:30:57
Language
English
Abstract
"Signal level is high but throughput is low" is a common experience in WLAN networks without central management. That causes a lot of frustration, mainly because there is no easy way for users to OBSERVE the presence of interference at all.

In order to improve this situation we developed a patch for OpenWRT which makes interference from other sources visible and is able to display the current utilization-ratio (channel load). No additional hardware is required and no interruption of normal operation is necessary - because recent chipsets maintain internal counters for channel load tracking.

We all love WLAN/IEEE802.11 networks. It's wonderful what we do with a few slices of free spectrum without the need for any central coordination.

The Problem is: demand for these few radio resources is increasing faster than additional free spectrum gets allocated. A potential tragedy of the commons situation is approaching.

Additionally, there is a heavy new user on the block: mobile operators want to start utilizing those free 5GHz bands. Protocols labelled License-Assisted-Access (LAA) or LTE-Unlicensed (LTE-U) have been put into silicon and large scale rollout can be expected to start during 2016.

This talk presents a modification to OpenWRT that will help coping with increased interference load over the next years. We think this feature is necessary to avoid a tragedy-of-the-commons situation in license-exempt bands (2.4/5GHz) due to ever increasing demands and node densities. The same way as we would be frustrated when we are unable to measure the general noise level in a room prior to deciding to use it to have a verbal conversation in it.

We started testing this feature (modifications to the mac80211 sublayer and to luci) at this years BattleMeshV8 in Maribor, Slovenia. Public release is planned for November 2015.

Talk ID
7314
Event:
32c3
Day
2
Room
Hall 2
Start
5:30 p.m.
Duration
00:30:00
Track
Hardware & Making
Type of
lecture
Speaker
Paul Fuxjaeger