【摘要】 在空天地一体化网络（space-air-ground integrated network,SAGIN）的发展与应用过程中，网络结构的复杂性与网络资源的多样性影响了SAGIN的服务能力。如何对异构网络进行资源分配优化以提升性能，是网络普及与应用过程中亟须解决的重要问题。首先，介绍了空天地一体化网络的架构与功能。随后，总结了网络资源优化中的若干典型问题、常见的优化目标和建模与优化方法。最后，分析了网络优化中存在的挑战，探讨了该领域未来的研究方向。更多还原

【Abstract】 In the development and application of the space-air-ground integrated network(SAGIN), the intricate network structure and varied resources significantly affect the service capabilities of SAGIN. It is a challenge in the popularization of SAGIN to allocate and optimize resources to improve the performance in heterogeneous networks.Firstly, the architecture and functions of SAGIN were introduced. Subsequently, several typical issues in resource optimization were summarized and analyzed, along with the common performance objectives, modeling and optimization methods. Finally, the challenges in network optimization were analyzed, and the future research direction in this field was discussed.更多还原