  The enormous quality of service (QoS) demands posed by mission-critical
use-cases of future 5G/6G wireless communication raise the need for
resource-efficient highly reliable and low latency connectivity solutions.
Multi-connectivity is considered a promising yet resource demanding approach to
enhance reliability. In this work, we study the potential of the rate-splitting
multiple access (RSMA) framework as an efficient way to enable uplink
multi-connectivity for data transmissions with particularly high reliability
requirements. Mapping high-criticality data onto the common stream allows it to
be decoded at multiple access points (APs), which enhances reliability, while
the private stream is utilized to serve applications with less stringent
requirements. We propose a criticality-aware RSMA-based transmission scheme
with short blocklength coding and derive an iterative power allocation
algorithm by means of successive convex approximation (SCA). The proposed
scheme is shown to achieve an expanded stability rate region compared to two
baseline schemes. Moreover, it turns out to be less impacted by short
blocklength while leading to substantial rate gains, particularly in the high
SNR regime.
