“Suppose “We-Connect” is a telecommunication company having a large digital cellular network. This company has a wireless network distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station (BS). A mobile phone is a portable device which receives or makes calls through a cell site (base station), or transmitting tower.
When the vehicle containing the Mobile Station (mobile phone) and the data terminal moves from one cell to another, handover occurs. This whole handover event can take 400ms and results in a line break during this time”.
According to the given Scenario, a mobile phone receives or send data through cell site or base station. BS is primary and mobile phones are secondary.
So, in my point of view Poll / Select type of Line Discipline is most suitable, because it is used for "Primary-Secondary Communication". In primary-secondary, one device controls many other devices and other must transmit through it.