(We created the Comcast Innovation Fund to support important research into the future of the Internet, with a focus on broadband, security and open-source development. In this series, we highlight grantees and their work.)        

The Comcast Innovation Fund is pleased to announce the award of a grant to support a research proposal entitled “Diagnosing/Diluting Wi-Fi Multicast Effects”, under the direction of Dave Täht of the Bufferbloat Project. 

This project builds upon the work from an earlier grant called “Make WiFi Fast”, which succeeded in speeding up Wi-Fi unicast traffic under load, while also reducing latency. The code from that project was folded into Linux 4.11, and the paper describing the benefits was published at USENIX 2017 ATC.

The new project addresses the potentially negative side effects of Wi-Fi multicast and power-save queues, a major issue for the Wi-Fi technology.  Applications and unicast traffic can be adversely affected when multicast and/or power save queues are over-used.

Applications that use Multicast DNS (mDNS), Universal Plug and Play (UPnP), IPv6 Neighbor Discovery (IPv6 ND) or Router Advertisement (IPv6 RA), Dynamic Host Configuration Protocol (DHCP and DHCPv6), or those that perform multicast file or sound transfer, are all potentially affected by this issue. 

The project aims to make Wi-Fi scale to more devices, with lower latency, combined with improved reliability and throughput.

The work will develop tests to identify issues, develop fixes that can be integrated into the Linux kernel, and write papers to explain and quantify the benefits.