A method of data transfer is using wireless radios and set up a wireless network. In this way the data in origin convert into radio waves and sent to the destination. The received radio waves re-convert to the data and will be delivered in the network.
First we evaluated the points of origin and destination. Many cases should be considered for equipment selection and establishing a wireless link that some of them are mentioned.
In wireless system with increasing distance, available bandwidth will reduce and with more distance bandwidth and speed will be decrease more until he link will be disconnected. Due to the bandwidth requirements for different distances should appropriate device should be selected to achieve optimum efficiency.
Wireless devices for data transmission use radio waves. Any other radio waves with the same frequency on the same route, causing chaos and destruction in signals that is called noise. Noise can be created by other wireless devices in the environment, high voltage cables, electromagnetic and similar devices and as a result it disconnects the link. To overcome the ambient noise we use wireless devices with multiple frequencies, using proper antenna, finding low noise channel and configuration to establish the best link.
Line of sight
To establish a Wireless link the antennas must have sight. It means sight should not be obstructed. Depending on the material it attracts the whole or part of the radio signal and the connection will be lost. To overcome obstacle first with special applications and maps we study the path and then we install tower with appropriate high to provide direct visibility between two points.
Radio signals sent to the destination, can be received with a wireless device in the middle of path. The data sent and received for the non-exposed and can be used. So the transmitted data can be sniffed by strangers.
To prevent this manufactures Research Institutes provide encryption to use in devices and in destination the devices decrypt the data. Another way for increasing security is ability to define opposite device and no other device can connect to the link.
The devices produced with companies have different parameters such as transmission power, antenna gain, cable, frequencies, device quality and security terms.
Implementation of local wireless is used in building for local network and internet access. For this we install an access point in a place with most coverage and then install wireless adaptor on the computers.
The wireless in open areas such as stadium and open gym, university yard, factories and similar place or connecting two long distance points should have tolerance ability to environmental condition and water proof.