Table 2 The parameter setting of the network

Cell radius \(R_{{\rm B}}\)

250 m

Video number in library \(N\)

20

Size of SVC encoded BL file \(L_{{\rm B}}\)

100 Mbit

Size of SVC encoded EL file \(L_{{\rm E}}\)

200 Mbit

Number of UAV stop points \(M_{{\rm SP}}\)

5

UAV flying height \(H_{{\rm U}}\)

200 m

Caching capacity of BS \(C_{{\rm B}}\)

1200 Mbit

Caching capacity of UAV \(C_{{\rm U}}\)

800 Mbit

Pathloss coefficient over the UAV-user link \(\beta_{{\rm U}}\)

2

Additional attenuation factor of NLoS connection \(\eta\)

20 dB

Power of complex additive white Gaussian noise \(n_{0}\)

− 120 dBm

Density of user distribution (PPP)\(\lambda_{{\rm U}}\)

\(5000/100^{2} \pi\)

Caching coefficient of UAV \(\mu_{{\rm C}}\)

\(6.25 \times 10^{ - 12}\) W/bit

Power efficiency coefficient of UAV power amplifier \(\mu_{{\rm T}}\)

4.7

Transmission bandwidth of UAV \(W_{{\rm U}}\)

1 MHz