Final brief3GPP TSG RAN WG2, 24 August to 28 August 2026, Maastricht. Last updated 2026-09-29.
3GPP Scout Meeting brief
RAN2 #135 · 2026-09-29
Top 3 things that happened on RAN2 #135 at RAN2 #135
The verdict
In the 6G connected-mobility study, RAN2 supported both network-triggered mobility and UE-triggered mobility with pre-configuration. Its early DL synchronization procedure uses a network command, while UE-triggered early DL synchronization remains FFS. These are study-phase agreements, not specification decisions. (R2-2605845, meeting or session report, paragraph 126. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip; R2-2605845, meeting or session report, paragraph 104. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip)
For Rel-20 NR AI/ML mobility, RAN2 agreed to reuse a preconfigured measurement gap per MO for inter-frequency prediction fallback. Without that gap, fallback is not allowed; the UE should stop inference if its full inference configuration becomes inapplicable. (R2-2605831, meeting or session report, paragraph 255. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip; R2-2605831, meeting or session report, paragraph 267. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip; R2-2605831, meeting or session report, paragraph 272. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
For predicted measurement events, RAN2 agreed that a future event predicted to fulfil TTT triggers a measurementReport. The UE reports the event's absolute timing as SFN+subframe. (R2-2605831, meeting or session report, paragraph 336. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip; R2-2605831, meeting or session report, paragraph 331. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip; R2-2605831, meeting or session report, paragraph 333. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
What was agreed
6G study, AI 9.4.1: mobility triggers and early DL synchronization. RAN2 supported network-triggered mobility and UE-triggered mobility with pre-configuration, while continuing the resource reservation study for both. For early DL synchronization, the network commands the UE to synchronize on target-cell reference signals; network-triggered synchronization applies to HO with or without pre-configuration.
AgreementBoth NW-triggered mobility and UE-triggered mobility with pre-configuration is supported in 6G. For both UE-triggered and NW-triggered mobility we continue the resource reservation study.
R2-2605845, meeting or session report, paragraph 126. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip
AgreementR2-2605845, meeting or session report, paragraph 104. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip
Rel-20 AI/ML mobility, AI 8.3.2: inference fallback. A preconfigured measurement gap per MO is reused for inter-frequency prediction fallback, and no fallback is allowed without one. The UE should stop inference when its full inference configuration becomes inapplicable.
AgreementPreconfigured measurement gap (per MO) is reused for fallback operation for inter-frequency prediction.
R2-2605831, meeting or session report, paragraph 255. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 267. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 272. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
Rel-20 AI/ML mobility, AI 8.3.2: partial configuration. A predicted-frequency list can be configured in otherConfig without corresponding co-located information, and the UE can feed back measured frequencies per predicted frequency with its applicability status. associatedId is optional per predicted frequency, and partial inference configuration in otherConfig is released upon RLF.
AgreementR2-2605831, meeting or session report, paragraph 286. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 292. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 294. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
Rel-20 AI/ML mobility, AI 8.3.2: predicted-event reports. A future measurement event predicted to fulfil TTT triggers a measurementReport. The UE reports the predicted event's absolute timing as SFN+subframe.
AgreementR2-2605831, meeting or session report, paragraph 336. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 331. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 333. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
Rel-20 AI/ML mobility, AI 8.3.2: network-sided measurements. For a network-sided model, the network can configure the number and interval of consecutive results in ReportConfigNR, for example one or multiple SMTCs; the UE reports the latest result when several exist for the same cell or frequency within an interval. Additional results need no timing information, but whether and how to report measurement absence remains FFS.
AgreementR2-2605831, meeting or session report, paragraph 372. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
AgreementR2-2605831, meeting or session report, paragraph 375. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip
Spectrum aggregation, AI 9.3.2.5: outgoing liaison. RAN2 approved an outgoing liaison on 6G-6G spectrum aggregation for non-collocated deployment scenarios.
Which mobility-control approach should guide connected-mode power saving?
Xiaomi proposed UE-based mobility with pre-configuration as the power-saving baseline. ETRI proposed studying DTX/DRX and measurement relaxation while retaining network-controlled mobility. Both were submitted to the meeting but not treated; the study agreement supporting both trigger paths does not select a power-saving-specific baseline.
XiaomiXiaomi proposes UE-based mobility with pre-configuration as the power-saving baseline.
For power-saving CONNECTED mobility study, UE based mobility with pre-configuration of candidate cells and with UE notification upon cell change (i.e., a CHO/C-LTM like mechanism) [...]
ETRIETRI proposes power-saving enhancements while retaining network-controlled mobility.
RAN2 studies enhancements to the existing power saving mechanisms in connected mode, such as DTX/DRX operation and measurement/reporting relaxation, while maintaining NW-controlled mobility.
Should inference continue when its full configuration becomes inapplicable and fallback is unavailable?
RAN2 agreed that the UE should stop inference when its full configuration becomes inapplicable, and that fallback is not allowed without a preconfigured measurement gap. This conflicts with China Telecom's proposed continuation and is in line with UNISOC's proposed stop. Neither contribution was adopted as such; both were noted.
China TelecomChina Telecom proposes continuing inference and reporting inapplicability when fallback is barred.
Proposal 1: If the full inference configuration becomes inapplicable and fall back is not allowed, UE continues inference operation and reports inapplicability status to the [...]
What benefits should frame study of non-collocated spectrum aggregation?
Fraunhofer IIS and Fraunhofer HHI emphasized peak data rate gains from CA and DC and observed that capacity can grow without aggregation. Verizon and co-submitters cited downlink and uplink field-test gains for non-collocated FR1-FR2 aggregation; their contribution was submitted to the meeting but not treated.
Fraunhofer IIS (with Fraunhofer HHI)Fraunhofer IIS and Fraunhofer HHI emphasize peak rate and capacity without aggregation.
Observation 1: Spectrum Aggregation (CA and DC) is mostly beneficial to peak data rate increase. [...]
Verizon (with Samsung, Qualcomm, NTT DOCOMO, Orange, Charter Communications, Xiaomi, OPPO, vivo)Verizon and co-submitters cite downlink and uplink field-test gains.
Observation 1: Field tests demonstrate substantial performance gains with both downlink and uplink spectrum aggregation for the non-collocated FR1-FR2 scenario.
Whether UE-triggered early DL synchronization might also be supported in the 6G study remains FFS. (R2-2605845, meeting or session report, paragraph 104. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip)
Resource reservation remains under study for both network-triggered and UE-triggered mobility. (R2-2605845, meeting or session report, paragraph 126. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip)
For temporal-domain case A, how to indicate explicit timing information remains FFS. (R2-2605831, meeting or session report, paragraph 357. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
The detailed value range and granularity for the prediction window, signalled in milliseconds, remain FFS. (R2-2605831, meeting or session report, paragraph 409. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
For network-sided models, whether and how to report measurement absence remains FFS. (R2-2605831, meeting or session report, paragraph 372. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
What to watch next meeting
At the next RAN2 meeting, watch whether the 6G study resolves UE-triggered early DL synchronization and advances the resource reservation study. (R2-2605845, meeting or session report, paragraph 104. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip; R2-2605845, meeting or session report, paragraph 126. R2-2605845, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605845.zip)
Watch for resolution of temporal-domain case A timing indication and the prediction window value range and granularity. (R2-2605831, meeting or session report, paragraph 357. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip; R2-2605831, meeting or session report, paragraph 409. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
Watch whether RAN2 resolves reporting of measurement absence for network-sided models. (R2-2605831, meeting or session report, paragraph 372. R2-2605831, 3GPP TSG RAN WG2 #135. https://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_135/Docs/R2-2605831.zip)
Sources
R2-2605845 Report from session on 6G Mobility (Nokia). Nokia. Meeting report. Register status: noted at R2-135.
R2-2605831 Report from session on R18/19 MOB, R19 NES and R20 AI/ML MOB. Session record; register lists Samsung as editor. Meeting report. Register status: approved at R2-135.
R2-2606040 LS on 6G-6G spectrum aggregation for non-collocated deployment scenarios. 3GPP RAN2. Outgoing LS. Register status: approved at R2-135.
R2-2604598 Discussion on 6G mobility. Xiaomi. Contribution. Register status: not treated at R2-135. No decision recorded in the register.
R2-2605577 Discussion on 6G Connected mode mobility. ETRI. Contribution. Register status: not treated at R2-135. No decision recorded in the register.
R2-2605032 Discussion on inference related LCM procedure. China Telecom. Contribution. Register status: noted at R2-135.
R2-2605271 Discussion on the inference related LCM procedure for AI Mobility. UNISOC. Contribution. Register status: noted at R2-135.
R2-2605743 FR1/FR2 operation based on carrier switching. Fraunhofer IIS (with Fraunhofer HHI). Contribution. Register status: available at R2-135. No decision recorded in the register.
R2-2605568 Requirements and Framework Evaluation for 6G Non-Collocated FR1-FR2 Aggregation Over Non-Ideal Backhaul. Verizon (with Samsung, Qualcomm, NTT DOCOMO, Orange, Charter Communications, Xiaomi, OPPO, vivo). Contribution. Register status: not treated at R2-135. No decision recorded in the register.
Coverage: RAN2 #135 (Maastricht, 2026-08-24 to 2026-08-28), agenda items 9.4.1, 8.3.2, 9.3.2.5. Scout read 28 recorded decisions and 139 company positions or contribution passages on these agenda items (catalog synced 2026-09-29) and cites 16 decisions and 6 positions from 9 TDocs. Every quoted passage was matched verbatim against the TDoc text; the summaries around the quotes are Scout's reading. Register statuses are copied from the 3GPP TDoc register: not treated means a document was not handled on its own, though its content may have fed feature-lead summaries or merged revisions. Not covered: other agenda items and meetings, plenary TDocs and plenary decisions after the meeting, email discussions after the meeting, and anything not yet in the chair notes or register.
The 6G mobility items are study-phase session agreements, not normative feature decisions.
For spectrum aggregation, the decision evidence establishes approval of an outgoing liaison but provides neither its content nor its recipient. It establishes no technical aggregation design agreement.
The power-saving and field-test positions identified as not treated are pre-meeting inputs, not recorded discussion outcomes.
Hottest topics
Connected mode mobilitysignificance 70 of 100, 55 TDocs
Inference related LCM proceduresignificance 70 of 100, 32 TDocs
Spectrum aggregationsignificance 65 of 100, 38 TDocs
Topology 2significance 65 of 100, 27 TDocs
NR NTN enhancementssignificance 64 of 100, 27 TDocs
Built by 3GPP Scout from the public meeting record (1474 TDocs registered, catalog synced 2026-09-29). Significance scores rank topics by decisions, contention, breadth and volume. Excerpts are at most 25 words and link to the original on the 3GPP file server.