## 3 System Model and Problem Formulation  
### Network Model  
As illustrated in Figure 1, the network comprises an access network and a backhaul network. The access network consists of base stations and Multi-access Edge Computing (MEC) servers. MEC servers, with computational capabilities and caching space, can be deployed at base stations or form small data centers. To simplify, MEC servers at the same location are abstracted as a single edge server representing a small data center. Base stations are connected to nearby small data centers via wired links. The backhaul network consists of one GEO satellite and multiple LEO satellites. LEO satellites host servers that provide computation and content retrieval services, while the GEO satellite acts solely as a data transmission relay. Satellites communicate with ground stations equipped with satellite transceivers via wireless links. In Figure 1, UE 1 receives caching services from LEO 1, while UE 2 is served by BS 2, which provides computing services. Given that BS 3 may be unable to supply the necessary computing services, UE 3 opts for LEO 2 for computing needs. As UE 4 falls outside the coverage of both BS and LEO, it resorts to using GEO to transmit its data to the ground cloud. \begin{table}
\begin{tabular}{c l l} \hline
**Ref.** & **Key Strength** & **Main Limitation** \\ \hline \multicolumn{3}{c}{Part 2.2: Interference Coordination Strategies} \\ \hline
[7] & \
\begin{tabular}{l} Proposes effective spectrum-sharing \\ approaches \\ \end{tabular} &
\begin{tabular}{l} Ignores dual-layer satellite \\ interference \\ \end{tabular} \\ \hline
[8] & Reduces interference with sidelobe control & Limited to Ku-band \\ \hline
[9] & Provides ITU standards for spectrum sharing &
\begin{tabular}{l} Lacks dynamic technical \\ solutions \\ \end{tabular} \\ \hline
[24] & \
\begin{tabular}{l} Details uplink interference analysis in \\ LEO-GEO networks \\ \end{tabular} &
\begin{tabular}{l} No resource optimization \\ proposals \\ \end{tabular} \\ \hline
[25] & \
\begin{tabular}{l} Analyzes downlink constraints in hybrid \\ networks \\ \end{tabular} &
\begin{tabular}{l} Lacks layered control \\ mechanisms \\ \end{tabular} \\ \hline
[26,27] & \
\begin{tabular}{l} Offer regulatory interference coordination \\ frameworks \\ \end{tabular} &
\begin{tabular}{l} Lack actionable algorithmic \\ strategies \\ \end{tabular} \\ \hline
[28] & Suggests spatial isolation techniques & Ignores broader strategies \\ \hline
[29] & ITU-R global standards for spectrum sharing &
\begin{tabular}{l} No technical implementation \\ methods \\ \end{tabular} \\ \hline
[30] & Simplifies RFI estimation in NGSO systems & Lacks mitigation techniques \\ \hline
[31] & \
\begin{tabular}{l} Controls interference with joint power and \\ tilt control \\ \end{tabular} &
\begin{tabular}{l} Requires complex coordination \\ efforts \\ \end{tabular} \\ \hline
[32] & \
\begin{tabular}{l} Improves coexistence with optimal power \\ control \\ \end{tabular} &
\begin{tabular}{l} Limited to power-focused \\ solutions \\ \end{tabular} \\ \hline
[33] & \
\begin{tabular}{l} Enhances spectrum sharing with cooperative \\ strategies \\ \end{tabular} &
\begin{tabular}{l} Lacks caching/computation \\ integration \\ \end{tabular} \\ \hline
[34] & \
\begin{tabular}{l} Maximizes spectral efficiency using NOMA \\ pairing \\ \end{tabular} &
\begin{tabular}{l} Constrained to NOMA-specific \\ systems \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 1: \(Cont.\)This network can be modeled as a directed graph \(G(\mathcal{D},\mathcal{L})\), where \(\mathcal{D}\) represents the set of nodes and \(\mathcal{L}\) represents the set of links. The node set \(\mathcal{D}\) includes users \(\mathcal{M}\) and service nodes \(\mathcal{N}\) (base stations, small data centers, satellites, and cloud servers). For network nodes without deployed servers, the caching and computational capacities are set to zero.