NTN Slot Format Indication for Cross-Slot Timing Alignment

The patent applies dynamics by making the slot format flexible and adjustable rather than fixed. The base station can dynamically indicate different slot formats to user equipment based on current satellite position, movement speed, and propagation delay conditions. This allows the system to adapt the uplink symbol timing and slot structure in real-time to prevent cross-slot boundary reception issues while maintaining timing alignment through partial TA.

The patent changes the parameter of slot format configuration to resolve the contradiction. By introducing flexible symbol indications and allowing dynamic adjustment of slot formats (including making entire slots flexible or adjusting individual symbol types), the system can modify timing parameters to ensure uplink transmissions complete before slot boundaries, thereby preventing reception issues while maintaining accurate timing alignment.

The patent applies local quality by making specific parts of the slot format adjustable rather than changing the entire structure. Individual symbols within slots can be marked as flexible, or specific slots can be made flexible, allowing localized timing adjustments for uplink transmissions affected by satellite propagation delays while keeping the rest of the communication structure simple and compatible with legacy systems.

The patent achieves universality by designing a slot format indication mechanism that can serve multiple functions: it maintains compatibility with legacy slot formats for simple cases while providing enhanced flexibility for NTN scenarios with high altitudes and propagation delays. The same indication mechanism works for both terrestrial and non-terrestrial networks, allowing a single system to handle diverse timing requirements.

The patent applies dynamics by making slot formats adjustable based on actual network conditions rather than always using flexible formats. The base station can dynamically select between legacy and flexible slot formats depending on satellite position, speed, and propagation delay, thereby achieving accurate timing alignment only when necessary while maximizing resource utilization in conditions where legacy formats suffice.

The patent changes the parameter of slot format flexibility selectively. Rather than making all slots flexible (which would reduce resource utilization), the system changes the format parameter only for specific slots or symbols where timing alignment issues occur due to NTN propagation characteristics. This selective approach maintains timing accuracy where needed while preserving resource efficiency elsewhere.