On Thursday, the Federal Council stated the national rail operator would have to provide free internet connection on its long-distance trains by December 2019.
The answer came in response to a formal request for information about the implementation of WLAN on public transport from Christian Democrat MP Thomas Ammann in June, Swiss regional daily the Luzerner Zeitung reported.
Ammann said he happy with the government's response on Thursday. He added he would monitor the SBB'S compliance and keep up the pressure on the rail operator.
The Federal Council's response put the ball squarely back in the SBB's court over the issue of getting online while onboard.
In early May, the SBB appeared to rule out the option but only weeks later SBB Chairman of the Board Monika Ribar did an about-turn and said the service would be provided, adding details would be forthcoming in the second half of this year.
The SBB has already ruled out using WLAN on trains to provide free internet, arguing it is too expensive. It is yet to supply details on other possible technical solutions.