A challenge posed by using mobile networks is these devices are external to your network. They bypass your internal security infrastructure and are difficult to monitor and manage because they are not connected to your infrastructure.
In the case of IoT devices or public transport systems, these devices will typically require access to resources within a private network. Various complex solutions are typically put in place to solve these challenges, such as VPNs, proxy servers and devices “phoning home” these solutions are difficult to provision and manage, and add additional cost.
As well as mobile devices being protected by your security infrastructure in the same way as any other device connected to your infrastructure would be, the devices are also directly manageable as they are directly connected to your network.