Wireless Communications - Bluetooth

Wireless communications are present in many of our daily activities and their use has become so common that we lose the perception of how useful and sometimes essential they might be. Cellular networks transmitting voice and data have emerged to provide the mobility and availability of communication that the accelerated pace of life in the big city demands. The use of radio frequency and infrared sensors provide the convenience of remote control to operate electronic devices making easier to perform our daily tasks.

Bluetooth is part of the technologies developed to provide wireless communication for use in personal areas. However, its use goes beyond the elimination of wires, as it is flexible enough to allow the creation of applications that open a world limited only by the imagination. 

Bluetooth is a technology developed by Ericsson in 1994, which makes possible wireless connectivity between devices within a short distance, they may form networks with different communications equipment: mobile computers, pagers, cell phones, PDAs, and even home appliances.

Features 

• Wireless. Replaces wired connections at distances not exceeding 10 meters, reaching speeds of 1Mbps.
  
• Automatic communication. The structure of the protocols that conforms it favors the communication automatically without requiring to be started by the user.
  
• Low power consumption.
  
• Integration of services. Can support voice and data transmissions simultaneously.
  
• Omnidirectional transmission. Because it's based on radio communications, does not require line of sight and allows multipoint configurations.
  
• Security. Uses Spread Spectrum Frequency Hopping as multiplexing technique, which reduces the risk that communications are intercepted or have interference with other applications. Also provides specifications for authenticating devices attempting to connect to the Bluetooth network, as well as in the handling of encryption keys to protect the information.
  
• Establishment of networks. Has the characteristic of forming a network topology where a device acts as master and up to seven more operate as slaves.
  

Bluetooth vs. Infrared 

• Both protocols specify a short-distance wireless communication, some people assume that Bluetooth could replace the infrared applications for the clear advantages it provides, which are deducted from their own characteristics.
  
• Due to the similarity of applications, it is important to identify the advantages between the two technology.
  
• The infrared requires linear communication between transmitter and receiver, which makes the line of sight imperative for its effective transmission.
  
• The frequencies of the infrared band does not allow penetration through walls, giving an important advantage to the radio frequency that the Bluetooth technology operates.
  
• The infrared communication is always one to one, leaving the out multipoint configurations.
  
• Bluetooth allows the generation of networks.