But even without ciphering, it means the ciphering is actually A5/0. In this case, isn’t there still a cipher command which contain the ciphering A5/0 ?
But using ciphering is mandatory since it’s the only way to avoid anyone being able to eavesdrop on any conversation in your network.
If some people from your government or from companies are using your network, they wouldn’t be very happy if they knew their calls are not protected.