SafetyNet offers two solutions

Long Range SafetyNet

The long-range system is designed primarily for an application which makes sure that several objects remain where they are supposed to be. Ideally, the long-range system should be able to track an object no matter how far away from the safe zone it is. This will require a network infrastructure in order to transfer data between the object, the safe zone terminal, and the end users. Location of the object is not a complex issue, as a system such as GPS or AGPS can be easily and cheaply implemented. As well as this, tracking within the safe zone can be efficiently carried out using RFID. In certain cases, it may be more efficient for the objects to be transmitting their location at all times, and define the safe zone in software.
A database of information regarding the objects to be tracked will be needed, including the ID, present and past location data, and any other necessary information, such as contact details of the owner. This database should be accessible from the internet, and there should also be a system in place to inform the system administrator and the owner if the object leaves the safe zone.

Portable SafetyNet

This system focuses much more on a scenario in which a supervisor is actively monitoring a group of objects. The hardware involved is one handheld device which creates the safe zone, and can display information about the number of objects being tracked and their distance from the device. We should calculate how far away each object is, and if it exceeds a preset value, the user will be informed, and the distance and direction of the object will be displayed on the screen.
In the following sections, we will carry out a feasibility study of the Portable SafetyNet system. We have chosen to study this over the former system because it is more localised, and we can concentrate more on specific location techniques, rather than the network infrastructure and software required in the long-range solution.

Why SafetyNet

Keeping track of personal possessions and people is important to us. Loss and theft of valuable items is not uncommon nowadays, and knowing whether or not your child is safe is always a parent's major worry. One child goes missing every four minutes in the UK, almost 95,000 per year. As well as children, disabled people, particularly young adults, who do not have any situational awareness or a sense of danger could get lost and very quickly find their way into trouble. In all cases, especially if they are vulnerable, it is important to look after the person and ensure they are safe, while trying not to restrict their freedom. A vulnerable person going missing puts a massive strain on the family or carers involved, and anything that could help them or the police find the missing person would be a huge benefit.

Theft of valuable or important possessions can also pose difficulties. Living and studying in London we have found first hand that bike theft is very common. Bike locks can provide considerable protection against thieves, but they can be broken or removed and the bike can still be stolen. In 2010, 115,000 bikes were reported stolen in the UK by a British crime survey conducted by the Home Office, but in fact over 500,000 bikes were stolen that year - a huge difference. Even when the theft is reported, it is often impossible to know the exact time the bike was stolen, particularly if the owner had not returned within a few hours. This inaccuracy in the time of the theft greatly hinders the police's ability to find and return it.

The results of our research into existing products show that the main disadvantage of existing track and trace systems is that they are largely designed to track no more than one object at a time. This can prove expensive and inconvenient where more than one object needs to be tracked.