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EP-4740586-A1 - METHOD AND APPARATUS RELATING TO L1/L2 TRIGGERED MOBILITY (LTM)

EP4740586A1EP 4740586 A1EP4740586 A1EP 4740586A1EP-4740586-A1

Abstract

The disclosure relates to a 5 th generation (5G) communication system or a 6 th generation (6G) communication system for supporting higher data rates beyond a 4 th generation (4G) communication system, such as long term evolution (LTE). A method of managing execution failure of L1/L2 triggered mobility (LTM), in a user equipment (UE), communicatively coupled to a telecommunication network is provided. The method includes if an initial LTM execution attempt fails, performing, by the UE, cell selection, and if the selected cell is an LTM candidate cell and if the UE has been configured by the telecommunication network to attempt LTM after an LTM execution failure, the attempting, by UE, a further LTM execution.

Inventors

  • KIM, DONGGUN

Assignees

  • Samsung Electronics Co., Ltd.

Dates

Publication Date
20260513
Application Date
20240731

Claims (14)

  1. A method of managing execution failure of L1/L2 triggered mobility (LTM), in a user equipment (UE), communicatively coupled to a telecommunication network, the method comprising: if an initial LTM execution attempt fails, performing, by the UE, cell selection; and if the selected cell is an LTM candidate cell and if the UE has been configured by the telecommunication network to attempt LTM after an LTM execution failure, attempting, by the UE, a further LTM execution.
  2. The method of claim 1, wherein, if the further LTM execution fails, then the UE attempts reestablishment.
  3. The method of claim 1, wherein execution failure is detected by one or more of expiry of a supervisor timer, radio link failure (RLF), or beam failure detection (BFD).
  4. The method of claim 1, wherein the LTM candidate cell is configured via an RRC connection.
  5. The method of claim 1, wherein the LTM execution failure is detected for a master cell group (MCG).
  6. The method of claim 1, wherein, if the LTM execution failure is detected for a secondary cell group (SCG), and if MCG transmissions of radio bearers is not suspended, then the UE reports failure to a master node of the MCG and does not attempt reestablishment.
  7. The method of claim 1, releasing, by the UE, an LTM configuration upon reception of an RRCRelease message indicating a transition to RRC IDLE mode.
  8. A user equipment (UE), communicatively coupled to a telecommunication network, configured to perform a method of managing execution failure of L1/L2 triggered mobility (LTM), the UE comprising: memory storing one or more computer programs; and one or more processors communicatively coupled to the memory, wherein the one or more computer programs include computer-executable instructions that, when executed by the one or more processors individually or collectively, cause the UE to: if an initial LTM execution attempt fails, perform cell selection; and if the selected cell is an LTM candidate cell and if the UE has been configured by the telecommunication network to attempt LTM after an LTM execution failure, attempt a further LTM execution.
  9. The UE of claim 8, wherein, if the further LTM execution fails, then the UE attempts reestablishment.
  10. The UE of claim 8, wherein execution failure is detected by one or more of expiry of a supervisor timer, radio link failure (RLF), or beam failure detection (BFD).
  11. The UE of claim 8, wherein the LTM candidate cell is configured via an RRC connection.
  12. The UE of claim 8, wherein the LTM execution failure is detected for a master cell group (MCG).
  13. The UE of claim 8, wherein, if the LTM execution failure is detected for a secondary cell group (SCG), and if MCG transmissions of radio bearers is not suspended, then the UE reports failure to a master node of the MCG and does not attempt reestablishment.
  14. The UE of claim 8, wherein an LTM configuration is released by the UE upon reception of an RRCRelease message indicating a transition to RRC IDLE mode.

Description

METHOD AND APPARATUS RELATING TO L1/L2 TRIGGERED MOBILITY (LTM) The disclosure relates to layer 1 (L1)/layer 2 (L2) triggered mobility (LTM). More particularly, the disclosure relates to a method of managing execution failure of LTM in a user equipment (UE), communicatively coupled to a telecommunication network. Considering the development of wireless communication from generation to generation, the technologies have been developed mainly for services targeting humans, such as voice calls, multimedia services, and data services. Following the commercialization of 5G (5th-generation) communication systems, it is expected that the number of connected devices will exponentially grow. Increasingly, these will be connected to communication networks. Examples of connected things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machines, and factory equipment. Mobile devices are expected to evolve in various form-factors, such as augmented reality glasses, virtual reality headsets, and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6G (6th-generation) era, there have been ongoing efforts to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as beyond-5G systems. 6G communication systems, which are expected to be commercialized around 2030, will have a peak data rate of tera (1,000 giga)-level bps and a radio latency less than 100μsec, and thus will be 50 times as fast as 5G communication systems and have the 1/10 radio latency thereof. In order to accomplish such a high data rate and an ultra-low latency, it has been considered to implement 6G communication systems in a terahertz band (for example, 95GHz to 3THz bands). It is expected that, due to severer path loss and atmospheric absorption in the terahertz bands than those in mmWave bands introduced in 5G, technologies capable of securing the signal transmission distance (that is, coverage) will become more crucial. It is necessary to develop, as major technologies for securing the coverage, radio frequency (RF) elements, antennas, novel waveforms having a better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antennas, and multi antenna transmission technologies such as large-scale antennas. In addition, there has been ongoing discussion on new technologies for improving the coverage of terahertz-band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable intelligent surface (RIS). Moreover, in order to improve the spectral efficiency and the overall network performances, the following technologies have been developed for 6G communication systems: a full-duplex technology for enabling an uplink transmission and a downlink transmission to simultaneously use the same frequency resource at the same time; a network technology for utilizing satellites, high-altitude platform stations (HAPS), and the like in an integrated manner; an improved network structure for supporting mobile base stations and the like and enabling network operation optimization and automation and the like; a dynamic spectrum sharing technology via collison avoidance based on a prediction of spectrum usage; an use of artificial intelligence (AI) in wireless communication for improvement of overall network operation by utilizing AI from a designing phase for developing 6G and internalizing end-to-end AI support functions; and a next-generation distributed computing technology for overcoming the limit of UE computing ability through reachable super-high-performance communication and computing resources (such as mobile edge computing (MEC), clouds, and the like) over the network. In addition, through designing new protocols to be used in 6G communication systems, developing mecahnisms for implementing a hardware-based security environment and safe use of data, and developing technologies for maintaining privacy, attempts to strengthen the connectivity between devices, optimize the network, promote softwarization of network entities, and increase the openness of wireless communications are continuing. It is expected that research and development of 6G communication systems in hyper-connectivity, including person to machine (P2M) as well as machine to machine (M2M), will allow the next hyper-connected experience. Particularly, it is expected that services such as truly immersive extended reality (XR), high-fidelity mobile hologram, and digital replica could be provided through 6G communication systems. In addition, services such as remote surgery for security and reliability enhancement, industrial automation, and emergency response will be provided through the 6G communication system such that the technologies could be applie