Location Dependent Allocation of Timers and Buffers at Layer-2 in LEO Based 5G-NTN

The integration of Terrestrial Networks (TN) and
Non-Terrestrial Networks (NTN), primarily utilizing satellites,
has gained significant attention due to the potential of NTN
to provide widespread coverage. The unique physical layer
properties of 5G-NR offer the possibility of direct access to 5G
services through satellites. However, the substantial Round-Trip
Delays (RTD) associated with NTNs necessitate a re-evaluation
of the design of timers and buffers in the RLC and PDCP layers.
This is particularly crucial for regenerative payload satellites with
limited computational resources that require optimal utilization
of the available resources. This research aims to explore the
integration of emerging NTNs with limited resources from a
higher-layer perspective. We propose a novel and efficient method
for designing the buffers and timers in the RLC and PDCP
layers without the need for intensive computations. Since the
optimal solution depends on the RTD, which might result to be
different for users located at different spots of the satellite beam,
a user location-dependent approach is adopted. This approach
is particularly relevant for efficiently utilizing the available
limited resources and avoiding unnecessary delays in the system.
Through simulations, we demonstrate that the proposed methods
significantly improve performance in terms of resource utilization
and reducing delays.