Table 1 Main notation
Notation | Definition |
|---|---|
K | Number of IoRT devices |
U | Number of UAVs |
\({\textbf{w}}_k\) | 2D coordinates of the k-th IoRT device |
\({\textbf{w}}_u\) | 2D coordinates of the u-th UAV |
\(H_u\) | Flight altitude of the u-th UAV |
\(H_s\) | Height of LEO satellite |
\(\rho _0,\beta _0\) | Channel power gain at reference distance of 1m |
\(\sigma ^2,\delta ^2\) | Power spectral density of Additive Gaussian White Noise (AWGN) |
\(d_{k,u}\) | The distance between the k-th IoRT device and the u-th UAV |
\(d_{\text {min}}\) | Minimum safe distance between UAVs and IoRT devices |
\(h_{k,u}\) | Channel power gain from the k-th IoRT device to the u-th UAV |
\(h_{u,s}\) | Channel power gain from the u-th UAV to LEO satellite |
\(p_k\) | The transmission power of the k-th IoRT device uploading data to UAV |
\(p_u\) | The transmission power of the u-th UAV uploading data to LEO satellite |
\(\gamma _{k,u}\) | The SINR of the k-th IoRT device transmitting data to the u-th UAV |
\(\gamma _{u,s}\) | The SNR of the u-th UAV transmitting data to LEO satellite |
\(P_k^{\text {max}},P_u^{\text {max}}\) | Maximum transmission power of IoRT devices and UAVs |
B | System bandwidth |
\(r_u\) | Coverage radius of the u-th UAV |
\(r_u^{\text {max}}\) | Maximum coverage radius of UAVs |