en:developers:summits:duesseldorf-2014
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| + | Proposal for Wireless Networking Micro-conference at Linux Plumbers Conference 2014 in Düsseldorf, Germany... | ||
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| + | [[http://wiki.linuxplumbersconf.org/2014:network_wireless|http://wiki.linuxplumbersconf.org/2014:network_wireless]] | ||
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| + | etherpad notes (copied from [[https://etherpad.fr/p/LPC2014_Wireless|https://etherpad.fr/p/LPC2014_Wireless]]) | ||
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| + | <code>Wireless Networking Microconference Notes | ||
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| + | Welcome to Linux Plumbers Conference 2014. | ||
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| + | The structure will be short introductions to an issue or topic followed by a discussion with the audience. A limit of 3 slides per presentation is enforced to ensure focus and allocate enough time for discussions. | ||
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| + | Please use this etherpad to take notes. Microconf leaders will be giving a summary of their microconference during the Friday afternoon closing session. | ||
| + | Please remember there is no video this year, so your notes are the only record of your microconference. | ||
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| + | Schedule | ||
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| + | 1:30 -- What's missing for Miracast? -- David Herrmann | ||
| + | miracast = wireless display, essentially | ||
| + | demo - using laptop as sink (projector), phone as source | ||
| + | software built using wpa_s | ||
| + | few ms delay (demo with game) | ||
| + | low framerate (30fps) | ||
| + | his software also implements the source side | ||
| + | his implementation shows up the data as a separate GPU which is problematic for the current UI stack, Wayland helps here | ||
| + | different USB wifi devices failed horribly, demo using Intel PCIe, only one USB (Atheros) worked at all | ||
| + | why separate GPU - why not use virtual output from GPU? should be supported and let the GPU encode the stream? implementation is also providing userspace APIs to bypass decode/encode | ||
| + | |||
| + | what really is missing? | ||
| + | - supplicant that works - e.g. P2P_DEVICE support can cause spurious errors | ||
| + | - NetworkManager/Connman support for P2P (the latter is WIP) | ||
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| + | 1:45 -- Extremely high speed and high coverage home wifi -- Avery Pennarun | ||
| + | 2:00 -- Cloud-based wireless packet capture, sharing, analysis, and diagnosis -- Avery Pennarun | ||
| + | "How we're doing WiFi @Google Fiber" | ||
| + | problem of selling gbit service - wifi is too slow, WAN faster than LAN | ||
| + | no longer a question of whether customers will be disappointed or not, just a matter of how disappointed :) | ||
| + | wifi speeds drop with distance - so now APs in each TV box; this causes problems roaming | ||
| + | http://6-dot-gfblip.appspot.com/ - measures latency in http session, can do DNS queries | ||
| + | new version will record & upload the data for customer support purposes | ||
| + | other tool: isoping to measure upstream/downstream latency/jitter | ||
| + | http://wavedroplet.appspot.com/ - upload pcap (radiotap headers) and show 802.11 data graphed | ||
| + | q: bufferbloat, how does it affect you? | ||
| + | a: when things are going well the systems often can't even catch up with the wan link so not a problem there; solutions to bufferbloat all on ethernet so far but wifi is really what they need, where it's a much harder problem | ||
| + | ... | ||
| + | network stack may have to be changed to deal with more dynamic queues due to changing stations/link conditions | ||
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| + | 2:15 -- Break | ||
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| + | 2:30 -- AP Group Features -- Helmut Schaa | ||
| + | AP group is a set of APs managed centrally, a lot of problems could be solved with such a framework if it were to exist | ||
| + | proposal to create a new protocol specific to hostapd for cooperation between APs | ||
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| + | 2:45 -- "Minstrel-Blues" - Practical Joint Rate und Power Control in Linux mac80211 with todays 802.11b/g/a/n Chips -- Thomas Huehn | ||
| + | rate control algorithm that incorporates tx power adjustment to reduce interference | ||
| + | modifications to minstrel, working w/ ath5k & ath9k | ||
| + | new mac80211 driver flags for power control capabilities | ||
| + | current work to extend to minstrel_ht | ||
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| + | 3:00 -- generalized firmware coredump support -- Johannes Berg | ||
| + | framework merged in 3.18 | ||
| + | register a buffer or method for access | ||
| + | creates device_coredump device class in sysfs | ||
| + | implemented in iwlwifi | ||
| + | not specific to wifi drivers | ||
| + | |||
| + | 3:15 -- Break | ||
| + | |||
| + | 3:30 -- randomized MAC address scanning -- Johannes Berg | ||
| + | originally from Apple (keybote), helps with privacy concerns | ||
| + | implementation in hostapd | ||
| + | When to randomize? randomization breaks some use cases | ||
| + | only when not associated? pre-association exchanges | ||
| + | should not be enabled by default -- end user option? probably... | ||
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| + | 3:45 -- Batman mesh -- Simon Wunderlich | ||
| + | overview of l2 mesh technology, generally used w/ wireless networking | ||
| + | mesh connection based on ad-hoc links | ||
| + | protocol decisions based on packet loss (OGMv2) | ||
| + | url: open-mesh.org | ||
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| + | 4:00 -- 802.11s mesh -- Kathy Giori | ||
| + | new life for 802.11s, QCA acquired copyrights from Cozybit for firmware (could be used in ath10k) | ||
| + | some implementations can work better by breaking the spec slightly -- will we accept patches? (likely yes, not guaranteed) | ||
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| + | 4:15 -- regulatory -- Luis Rodriguez | ||
| + | efforts to push CRDA functionality into the kernel | ||
| + | timing issues exist w/ userland implementation, some use the in-kernel static database instead | ||
| + | use in-kernel signing infrastructure to validate rules database BLOBs coming from userland</code> | ||
en/developers/summits/duesseldorf-2014.txt · Last modified: 2015/01/26 09:49 (external edit)
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