Mobile cellphone tracking follows the same basic process as GPS, only that local cellphone towers are used to record and convey the location of a certain user (at a certain time etc). The technology allows this data to be similarly viewed via an Internet connection from a remote position.
Basically, you can monitor anyone who has a cellphone based on where and when they are using it. But there are a few conditions. There are a number of service companies who can easily set up this method of surveillance, but legally you must get approval from the owner of the cellphone you want to monitor.
If you are a father monitoring your child, this may not be an issue (especially if you are the one who buys the phone!). It’s more of a problem, however, when you need to spy. In the past, it was possible to circumvent this approval process by “borrowing” the target phoneand approving the tracking operation yourself.
This is of course against the rules. Today, these services are issuing periodic reminders to the cellphone being tracked informing its user of this fact. Nevertheless, it remains a much less expensive option for individuals compared to GPS tracking, as there is no need for additional hardware.