Network Element Placement for Space‐Air‐Ground Integrated Network: A Tutorial

With the demand for Internet connectivity in remote areas, space-air-ground integrated network (SAGIN) was proposed to achieve ubiquitous coverage and enhance service capabilities of extant terrestrial networks. The paradigm virtual element placement (NEP) is applied into SAGIN. It can save energy operating costs by placing specific elements (NEs) as software instances. In addition, it helps provide services end-to-end networks with its ability allocate manage resources flexibly. However, NEP faces some challenges topologies be dynamic, links such satellite-to-ground air-to-ground ones are prone fail. These will make management more complicated. Moreover, static schemes hard accommodate time-varying traffic. this context, work explains problem SAGIN from three aspects, i.e., radio access (RAN), core (CN), barrier (BN). First, physical networking architectures introduced. Then status corresponding described these two aspects. Finally, paper discusses future research directions key technical challenges.