PC CONTROLLED SPY VEHICLE
1.1 RF Spy Vehicle
RF spy vehicle is very essential and useful for the army and other intelligence agencies. Intelligent spy robot project has been designed for the spying purpose. It is radio controlled. Much time our army soldiers need to venture into the enemy area just to track their activities. Which is often a very risky job, it may cost precious life. Such dangerous job could be done using small spy robot. All the developed and advance nations are in the process of making combat robot design, a robot that can fight against enemy. This robot is just a step towards similar activity.
This robot is radio operated, self-powered, and has all the controls like a normal car. This is not possible until a wireless camera is installed. Wireless camera will send real time video and audio signals which could be seen on a remote monitor and action can be taken accordingly. Being in size small, will not be tracked by enemy on his radar. It can silently enter into enemy canopy or tent and send us all the information through its tiny camera eyes.
1.2 What is an RF?
RF is a rate of oscillation in the range of about 30 kHz to 300 GHz, which corresponds to the frequency of electrical signals normally used to produce and detect radio. RF usually refers to electrical rather than mechanical oscillations, although mechanical RF systems do exist.
The range of frequencies and power output determine how well RF signals can penetrate walls and other objects. Signals up to 2 GHz can generally go through dense objects, but from 2 GHz to 5 GHz, they have some difficulty. From 5 GHz to 50 GHz, signals require line of sight, but can traverse long distances. Signals above 50 GHz require line of sight, but only for short distances.
1.3 Special Properties of RF
Electrical currents that oscillate at RF have special properties not shared by direct current signals. One such property is the ease with which they can ionize air to create a conductive path through air. This property is exploited by ‘high frequency’ units used in electric arc welding, although strictly speaking these machines do not typically employ frequencies within the HF band. Another special property is an electromagnetic force that drives the RF current to the surface of conductors, known as the skin effect. Another property is the ability to appear to flow through paths that contain insulating material, like the dielectric insulator of a capacitor. The degree of effect of these properties depends on the frequency of the signals.
1.4 RF Spectrum
The term Radio Frequency (RF) refers to the electromagnetic field that is generated when an alternating current is input to an antenna. This field, also called an RF field or radio wave, can be used for wireless broadcasting and communications over a significant portion of the electromagnetic radiation spectrum — from about 9 kilohertz (kHz) to thousands of gigahertz (GHz). This portion is referred to as the RF Spectrum. As the frequency is increased beyond the RF spectrum, electromagnetic energy takes the form of infrared (IR), visible light, ultraviolet (UV), X-rays, and gamma rays.
Many types of wireless devices make use of RF fields — radio, television, cordless and cellular telephones, satellite communication systems, and many measuring and instrumentation systems used in manufacturing. Some wireless devices, such as remote control boxes and cordless mice, operate at IR or visible light frequencies. The RF spectrum is divided into several ranges, or bands. Each of these bands, other than the lowest frequency segment, represents an increase of frequency corresponding to an order of magnitude (power of ten). The chart at the top of the page depicts the eight bands in the RF spectrum, showing frequency and bandwidth ranges. 
GSM (Global System for Mobile communication) is a digital mobile telephony system that is widely used in Europe and other parts of the world. GSM uses a variation of time division multiple access (TDMA) and is the most widely used of the three digital