Meeting: TSGS4_135_India | Agenda Item: 7.8
[FS_ULBC] Updates of the permanent document based on 3GPP TR 23.700-19
vivo Mobile Communication Co.,
pCR
Agreement
SA2 has reached conclusions on Key Issue #1 regarding the support of IMS voice call over NB-IoT via GEO satellite connecting to EPC, as documented in TR 23.700-19. It has been agreed that voice packets shall be transported over the NB-IoT (GEO) user plane (UP) using DRB and S1-U, and that a single PDN connection shall be used for both IMS signaling and IMS voice. Furthermore, the TR specifies that the voice data transport mechanism of IP packets is mandatory (UP/IP, recommended with RoHC), whereas the mechanism involving the removal and restoration of parts of RTP/UDP/IP headers is optional (UP/non-IP). This contribution updates the FS_ULBC Permanent Document to align the transport path assumptions and solution details with these agreements.
| TDoc | S4-260386 |
| Title | [FS_ULBC] Updates of the permanent document based on 3GPP TR 23.700-19 |
| Source | vivo Mobile Communication Co., |
| Agenda item | 7.8 |
| Agenda item description | FS_ULBC (Study on Ultra Low Bitrate Speech Codec) |
| Doc type | pCR |
| For action | Agreement |
| Abstract | SA2 has reached conclusions on Key Issue #1 regarding the support of IMS voice call over NB-IoT via GEO satellite connecting to EPC, as documented in TR 23.700-19. It has been agreed that voice packets shall be transported over the NB-IoT (GEO) user plane (UP) using DRB and S1-U, and that a single PDN connection shall be used for both IMS signaling and IMS voice. Furthermore, the TR specifies that the voice data transport mechanism of IP packets is mandatory (UP/IP, recommended with RoHC), whereas the mechanism involving the removal and restoration of parts of RTP/UDP/IP headers is optional (UP/non-IP). This contribution updates the FS_ULBC Permanent Document to align the transport path assumptions and solution details with these agreements. |
| Release | Rel-20 |
| Specification | 26.94 |
| Version | 0.4.0 |
| Related WIs | FS_ULBC |
| download_url | https://www.3gpp.org/ftp/tsg_sa/WG4_CODEC/TSGS4_135_India/Docs/S4-260386.zip |
| For | Agreement |
| Spec | 26.94 |
| Type | pCR |
| Contact | Wang Dong |
| Uploaded | 2026-02-12T04:38:12.477000 |
| Contact ID | 107237 |
| TDoc Status | agreed |
| Is revision of | S4-260150 |
| Reservation date | 12/02/2026 04:32:58 |
| Agenda item sort order | 20 |