Capacity was further increased when phone companies implemented digital networks. Due to bandwidth limitations each cell will have a maximum number of cell phones it can handle at once. The cell towers are usually interconnected to each other and the phone network and the internet by wired connections. In the earliest mobile phone systems by contrast, all control was done manually; the customer would search for an unoccupied channel and speak to a mobile operator to request connection of a call to a landline number or another mobile. The [...]