Dear Osmocom community,
Over the past several months I've been working almost exclusively on improving FR1 and EFR speech handling in the Osmocom GSM network implementation. All of my Gerrit patches since March have been in this area, and my two Themyscira-branded public domain libraries for GSM codecs are also primarily intended for use together with Osmocom, specifically for implementation of transcoding media gateways that interconnect an Osmocom GSM network with a non-GSM outside world such as G.711 PSTN.
Given the knowledge I've gained over months of working in this area, and seeing that many other Osmocom developers aren't particularly familiar with these aspects of the specs (understandable: GSM is huge, can't keep everything in one's head), I would like to do an OsmoDevCall presentation on the topic of GSM speech handling with traditional non-AMR codecs. I would like to cover the following subtopics:
* What metadata bits (BFI, UFI, SID, TAF) are defined in the specs for transport of encoded speech between network elements, beyond the familiar speech codec bits themselves.
* What exactly are regular speech frames, SID frames, silence frames (a "silence frame" for FR1 codec is NOT the same thing as a SID frame!) and bad frame gaps, and which of these categories are allowed or not allowed to exist at each of the interfaces in the spec-defined GSM architecture.
* Which transformations are supposed to happen where: which network elements are responsible for bad frame handling, error concealment, comfort noise insertion or SID propagation.
* How these architectural principles, originally defined for the T1/E1 environment with TRAUs, can be carried over to an RTP environment.
* Relevant Osmocom components: OsmoBTS and the aspect of OsmoMGW that interfaces from RTP to T1/E1 Abis.
* What behavior changes have been effected by my patches to OsmoBTS and supporting libraries that have already been merged, and which behavior changes are still on my wish list or to-do list to implement and hopefully get merged.
Looking at the OsmoDevCall wiki page, I see absolutely nothing scheduled past May, and there was no OsmoDevCall in April - are we out of presenters? But we have just one problem: it seems that some people in the senior leadership of Osmocom organization don't want me presenting on OsmoDevCall, and recently even asked specifically for presentation ideas from "anyone other than Mychaela". I see two possible solutions to this problem:
Option 1: If the leaders in question could set aside their personal dislike of me and allow me to present on highly Osmocom-relevant topics (such as the FR/HR/EFR codec presentation proposal above) no different from other Osmocom developers, that would be the best solution.
Option 2: If those who control the scheduling of presentations on the official OsmoDevCall platform (the official BigBlueButton instance for ODC) are not willing to budge, the alternative will be for me and Das Signal (my dear friend and FreeCalypso sysadmin) to set up our own BBB instance on our own server, configure it to look and feel exactly like the official one used for ODC, hold presentations there during those months when no official ODC presentation takes place due to lack of non-excluded willing presenters, and invite everyone from Osmocom to join those unofficial ODC-like presentations.
So - which of the two is it going to be?
Sincerely, Mother Mychaela, operator of a non-profit GSM network based on Osmocom, contributing to Osmocom CNI development in conjuction with that network operation.