QML-IB: Quantized Collaborative Intelligence between Multiple Devices and the Mobile Network
Jingchen Peng, Boxiang Ren, Lu Yang, Chenghui Peng, Panpan Niu, Hao Wu
TL;DR
The paper addresses efficient task-specific data transmission for collaborative AI across multiple mobile devices and a network, introducing the multi-link information bottleneck (ML-IB) framework and a quantized variant (QML-IB). It defines a computable objective $\mathcal{C}_{\text{ML-IB}}$ balancing task accuracy and communication overhead, then derives a variational upper bound and a Log-Sum Inequality-based approximation to enable training with quantized communications. The proposed QML-IB algorithm trains device encoders, a network decoder, and a trainable quantizer to achieve high accuracy with low transmission cost, validated on MNIST and CIFAR-10 against a state-of-the-art baseline. Results show robust performance under varying latency, device counts, and channel conditions, with quantization incursing only negligible performance loss and even improving results in overlapping-data scenarios. The approach is applicable beyond AWGN to other fading channels, highlighting its practical relevance for 6G-native intelligent networks.
Abstract
The integration of artificial intelligence (AI) and mobile networks is regarded as one of the most important scenarios for 6G. In 6G, a major objective is to realize the efficient transmission of task-relevant data. Then a key problem arises, how to design collaborative AI models for the device side and the network side, so that the transmitted data between the device and the network is efficient enough, which means the transmission overhead is low but the AI task result is accurate. In this paper, we propose the multi-link information bottleneck (ML-IB) scheme for such collaborative models design. We formulate our problem based on a novel performance metric, which can evaluate both task accuracy and transmission overhead. Then we introduce a quantizer that is adjustable in the quantization bit depth, amplitudes, and breakpoints. Given the infeasibility of calculating our proposed metric on high-dimensional data, we establish a variational upper bound for this metric. However, due to the incorporation of quantization, the closed form of the variational upper bound remains uncomputable. Hence, we employ the Log-Sum Inequality to derive an approximation and provide a theoretical guarantee. Based on this, we devise the quantized multi-link information bottleneck (QML-IB) algorithm for collaborative AI models generation. Finally, numerical experiments demonstrate the superior performance of our QML-IB algorithm compared to the state-of-the-art algorithm.
