  Split learning (SL) has emerged as a promising approach for model training
without revealing the raw data samples from the data owners. However,
traditional SL inevitably leaks label privacy as the tail model (with the last
layers) should be placed on the server. To overcome this limitation, one
promising solution is to utilize U-shaped architecture to leave both early
layers and last layers on the user side. In this paper, we develop a novel
parallel U-shaped split learning and devise the optimal resource optimization
scheme to improve the performance of edge networks. In the proposed framework,
multiple users communicate with an edge server for SL. We analyze the
end-to-end delay of each client during the training process and design an
efficient resource allocation algorithm, called LSCRA, which finds the optimal
computing resource allocation and split layers. Our experimental results show
the effectiveness of LSCRA and that U-shaped parallel split learning can
achieve a similar performance with other SL baselines while preserving label
privacy. Index Terms: U-shaped network, split learning, label privacy, resource
allocation, 5G/6G edge networks.
