<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"><head><meta http-equiv=Content-Type content="text/html; charset=us-ascii"><meta name=Generator content="Microsoft Word 12 (filtered medium)"><style><!--
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</o:shapelayout></xml><![endif]--></head><body lang=EN-US link=blue vlink=purple><div class=WordSection1><p class=MsoNormal>Hi All,<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>I am trying to transmit voice with my GTA02 and Osmocom. Upon looking into code I did not find any code transmitting voice. I have tried to do it myself but without much success.<o:p></o:p></p><p class=MsoNormal>What have I done:<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>1.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span dir=LTR></span>Merge branch “jolly/voice” into main. <o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>2.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span dir=LTR></span>Add handling of L1CTL_VOICE_REQ at l23_api.c<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>3.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span dir=LTR></span>Create additional queue for voice requests to be handled within the scheduler<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>4.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span dir=LTR></span>Create “loopback” code, issuing L1CTL_VOICE_REQ each time voice is received at layer23<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>5.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span dir=LTR></span>At l1s_tch_cmd, add code, sending the frame from voice request queue, similar to code, sending FACCH frame.<o:p></o:p></p><p class=MsoListParagraph style='text-indent:-.25in;mso-list:l0 level1 lfo1'><![if !supportLists]><span style='mso-list:Ignore'>6.<span style='font:7.0pt "Times New Roman"'> </span></span><![endif]><span dir=LTR></span>During tests against OpenBTS, it appears, that the voice frames are being sent, but all of them have “Stolen” bit turned on, e.g. BTS considers them FACCH frames.<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>My question is how do I transmit TCH frame with “Stolen” indicator turned off.<o:p></o:p></p><p class=MsoNormal>Or even better, is there any other implementation of transmitting voice via TCH?<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Code fragment from l1s_tch_cmd, <o:p></o:p></p><p class=MsoNormal>------------------------------------------------------------------------------------------------<o:p></o:p></p><p class=MsoNormal> if (facch_tx_now) {<o:p></o:p></p><p class=MsoNormal> uint16_t *info_ptr = dsp_api.ndb->a_fu;<o:p></o:p></p><p class=MsoNormal> struct msgb *msg;<o:p></o:p></p><p class=MsoNormal> const uint8_t *data;<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal> /* Pull FACCH data (if ready) */<o:p></o:p></p><p class=MsoNormal> if (icnt > 26)<o:p></o:p></p><p class=MsoNormal> {<o:p></o:p></p><p class=MsoNormal> msg = msgb_dequeue(&l1s.tx_queue[L1S_CHAN_MAIN]);<o:p></o:p></p><p class=MsoNormal> if(!msg && (tch_mode == TCH_FS_MODE))<o:p></o:p></p><p class=MsoNormal> {<o:p></o:p></p><p class=MsoNormal> msg = msgb_dequeue(&l1s.tx_queue[L1S_CHAN_VOICE]);<o:p></o:p></p><p class=MsoNormal> if(msg && msg->l3h)<o:p></o:p></p><p class=MsoNormal> {<o:p></o:p></p><p class=MsoNormal> tx_sent++;<o:p></o:p></p><p class=MsoNormal> printf("rx_frames: %d tx_recv: %d tx_sent: %d\n", rx_frames, tx_recv, tx_sent);<o:p></o:p></p><p class=MsoNormal> printf("l1s_tch_cmd: voice data = %s\n", hexdump(msg->l3h, 33));<o:p></o:p></p><p class=MsoNormal> }<o:p></o:p></p><p class=MsoNormal> }<o:p></o:p></p><p class=MsoNormal> }<o:p></o:p></p><p class=MsoNormal> else<o:p></o:p></p><p class=MsoNormal> {<o:p></o:p></p><p class=MsoNormal> msg = NULL;<o:p></o:p></p><p class=MsoNormal> }<o:p></o:p></p><p class=MsoNormal>------------------------------------------------------------------------------------------------<o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal>Many thanks<o:p></o:p></p><p class=MsoNormal>Michael<br><br><o:p></o:p></p><p class=MsoNormal><o:p> </o:p></p><p class=MsoNormal><o:p> </o:p></p></div></body></html>