and the external circuit is described by ∂$_{τ}$ U = U$_{t}$ − U − R$_{s}$ j τ$_{s}$ , (1.18) where the total applied voltage is rescaled as U$_{t}$ = U$_{t}$/ ( E 0 Z 0 $_{)}$, dimensionless voltage U ( τ ) = ∫ L 0 E $_{dz}$, time scale τ$_{s}$ = T$_{s}$/t 0 , resistance R$_{s}$ = R$_{s}$ eµ$_{e}$n 0 /Z 0 , and spatially conserved total current j ( τ ) = ∂$_{τ}$ E + µρ E + σ $_{E}$. We consider a regime corresponding to a transition between Townsend and glow discharge. The parameters are taken as in the experiments [62] and in our previous work [3]. The discharge is in nitrogen at 40 mbar, in a gap of 1.4 mm. We used the ion mobility µ$_{i}$ = 23 . 33 cm $^{2}$/ (V s) and electron mobility µ$_{e}$ = 6666 . 6 cm $^{2}$/ $_{(V s)}$, therefore the mobility ratio is µ = µ$_{i}$/µ$_{e}$ = 0 . $_{0035}$. The secondary emission coefficient was taken as γ = 0 . $_{08}$. The applied voltages U$_{t}$ are in the range of 513–570 V. For α 0 = Ap = [27 . 8 µ m] − 1 and for E 0 = Bp = 10 . 3 kV / $_{cm}$, we used values from [57]. The semiconductor layer consists of 1.5 mm of GaAs with dielectric constant ε$_{s}$ = 13 . 1 and conductivity σ$_{s}$ = (2 . 6 × 10 5 Ω cm) − 1 . Corresponding dimensionless parameters are L $_{= 50}$, R$_{s}$ $_{= 30597}$, τ$_{s}$ $_{= 7435}$, and a total voltage range U$_{t}$ between 17 . 67 and 20 . 03 . In the present section, we will extend the spatiotemporal chaos of a drive GDS system through utilizing its voltage over the gas discharge as a chaotic control applied to the electric circuit of a response GDS system. In the coupling, the voltage over the discharge of the drive system is applied as a perturbation to the circuit equation of the response system. The presence of entrainment by chaos in the response system will be shown numerically. Moreover, we will compare our results with generalized synchronization. The full analysis of the spatiotemporal chaos in the GDS system (1.16-1.18) is provided in the Appendix, where the bifurcation diagram as well as the chaotic behaviors in the voltage, electric field, electron density and ion density of the system are represented. According to these results, the GDS system ∂$_{τ}$ σ − ∂$_{z}$ ( E σ ) = σ E α ( E ) , ∂$_{τ}$ ρ + µ∂$_{z}$ ( E ρ ) = σ E α ( E ) , ∂$_{z}$ E = ρ − σ, E = − ∂$_{z}$φ, ∂$_{τ}$ U = 20 − U − R$_{s}$ j τ$_{s}$ , (2.19) 8 2 Chaotically coupled GDS systems