Table 1 Parameter setting

Number of devices M

8

Number of CAPs N

2

Variance of the AWGN \(\sigma ^2\)

0.01

Bandwidth of nth CAP and the cloud server

{4 Mhz, 4 Mhz, 12 Mhz}

Computation capacity of nth CAP and the cloud server

{\(8 \times 10^8\), \(1.2 \times 10^9\), \(1.0 \times 10^{10}\) } cyc/s

Distribution of each device’s computation capacity \(f_m^l\)

\({\mathcal {U}} (1.0 \times 10^8, 1.5 \times 10^8)\) cyc/s

Distribution of the size of data stream

\(l_1 \sim {\mathcal {U}} (120, 160)\) Mb

\(l_2 \sim {\mathcal {U}} (130, 140)\) Mb,

\(l_3 \sim {\mathcal {U}} (60, 80)\) Mb,

\(l_4 \sim {\mathcal {U}} (40, 60)\) Mb

\(l_i \sim {\mathcal {U}} (40, 80)\)  Mb, \(\forall i>4\)

Transmit power \(p^{\text {trans}}_m\) of mth IoT device

1 W

Transmit power \(p^{\text {trans}}_n\) of nth CAP

2 W

Conversion factor \(\kappa\) from Mb to bit

\(2^{20}\)

CPU’s cycles for calculating one bit data stream \(\omega\)

40