Chapter 1 Introduction of 6G Heterogeneous Networks -- Chapter 2 Introduction of Cooperative Transmission in Heterogeneous Networks -- Chapter 3 Traffic Offloading in Heterogeneous Networks -- Chapter 4 Cooperative Resource Allocation in Heterogeneous Space-based Networks -- Chapter 5 Introduction of Cooperative Transmission in Integrated Satellite-Terrestrial Networks -- Chapter 6 Traffic Offloading in Satellite-Terrestrial Network -- Chapter 7 Cooperative Beamforming for Secure Satellite-Terrestrial Transmission -- Chapter 8 Traffic Prediction based Transmission in Satellite-Terrestrial Networks -- Chapter 9 Introduction of Cooperative Computation and Caching -- Chapter 10 QoS-Aware Computational Resource Allocation -- Chapter 11 QoS-Aware Caching Resource Allocation -- Chapter 12 Priority-Aware Computational Resource Allocation -- Chapter 13 Energy-Aware Computational Resource Allocation -- Chapter 14 Introduction of Cooperative Resource and Information Sharing -- Chapter 15 Cooperative Data Transaction in Mobile Networks -- Chapter 16 Cooperative Trustworthiness Evaluation and Trustworthy Service Rating -- Chapter 17 Cooperative Privacy Protection Among Mobile User -- Chapter 18 Conclusion.