Efficient Resource Allocation of Slicing Services in Softwarized Space-Aerial-Ground Integrated Networks for Seamless and Open Access Services

In current 6G study, space-aerial-ground integrated networks (SAGIN) are attracting the eye-catching attention. Traditional ground networks and facilities (e.g., open random access networks, Open-RAN) simply provide two-dimensional (2D) and limited-coverage services at low altitudes. SAGIN are designed to overcome these limitations and promise to provide 3D and seamless services and connectivity opportunities. Meanwhile, network softwarization (NetSoft) is highlighted as dominant 6G attribute. Through incorporating NetSoft, dedicated network appliance will be isolated as software blocks and general-purpose hardware. Initiated and customized services will be realized by chained software blocks and share the same underlying hardware. Thus, the resource usage and service diversity can be simultaneously achieved by adopting NetSoft. In current literature, SAGIN and NetSoft are well investigated. However, their joint research is at early stage. Therefore, we investigate the resource allocation in softwarized SAGIN for achieving open and seamless access services. We propose the efficient resource allocation and orchestration framework, abbreviated as Slice-Soft-SAGIN. Our framework approach is designed to achieve efficient resource allocation solution per slice service. Each time receiving one tailored slicing service, the first checking available resources will be conducted by our Slice-Soft-SAGIN. When passing the preliminary resource checking, the formal resource allocation of slicing service will be executed in order: first terrestrial node, second aerial node, third satellite node. In addition, our Slice-Soft-SAGIN executes wireless (spectrum) and wired (computing and storage) types of resources when serving this slicing service. This is one crucial highlight of our Slice-Soft-SAGIN framework. With the purpose of confirming merits of Slice-Soft-SAGIN, the comprehensive evaluation work is executed. Typical works and three extra counterparts constitute the whole evaluation. We analyze the evaluation results carefully.

I. Introduction

Existing networks, such as traditional core networks and the open random access networks (Open RAN), are deployed in the terrestrial regions. Therefore, current services and vertical commercial applications are realized in the ground networks. Take note that terrestrial and ground are used interchangeably in this paper. That is to say, these services and vertical applications belong to the two-dimensional (2D) type and are limited at low altitudes. Though existing satellite networks and aerial networks can provide 3D services and huge connectivity opportunities, these networks (terrestrial networks, aerial networks, satellite networks) have not been merged and run smoothly. In addition, service quality (e.g., end-to-end latency, service coverage) cannot be guaranteed. Consequently, 3D, seamless, open access and tailored services for large-scale commercial purposes and vertical applications cannot be well provided in existing traditional networks. However, these services are greatly requested and planned to come true in 2030 s. Based on current research situations, space-aerial-ground integrated networks (SAGIN) [1] are introduced in these years. Since SAGIN inception, they have been attracting extensive attention. Learning from released references and results [2], [3], SAGIN are the most crucial evolutionary direction and fundamental attribute of future networks, including 6G networks. As presented in Fig. 1, the structure of SAGIN is plotted. Within Fig. 1, SAGIN consist of three main layered networks (parts): satellite network part, aerial network part, and terrestrial network part. Within the satellite network part, three major types of satellite nodes are categorized, based on their heights above the ground. Three types of satellite nodes are geosynchronous orbit (GEO) satellite, medium earth orbit (MEO) satellite and low earth orbit (LEO) satellite, respectively. Within the aerial network part, multiple flying objects and platforms are included. These flying objects are the UAVs, balloons and so on. Following the classification criteria (different altitudes), two major types are included: high altitude platform (HAP), low altitude platform (LAP). Within the ground network part, traditional ground networks, such as traditional cellular networks, core networks and RAN [4], are involved.