Connecting to Internet

 What is an Internet connection 

The internet is the connection with a computer or network of computers have to connect to the Internet, allowing them to view Web pages from a browser and access other services offered by this network. There are companies that offer Internet access, which are called servers show a little history 
The global telephone network was designed to reproduce human voices clearly, to realize it uses a system that is capable of transmitting signals between 350Hz and 3400Hz. The conversion of analog signals to digital is called PCM ("Pulse Code Modulation"). 

Types of Internet connections



 Digital Network RDSI : is a phone line, but digital (instead of analog) from end to end. Instead of a modem, this type of connection uses a network adapter that translates the frames generated by the digital signal to the computer of a type that the network is prepared for transmitir.A physical level, the network requires a special wiring (usually UTF cable with RJ-45 connectors on the ends), so that the basic telephone infrastructure can not be used (and this, of course, expensive to use). 

Digital Network ADSL: ADSL (Asymmetric Digital Subscriber Line) combines the advantages of RTB and ISDN, which soon became the favorite type of household connection and ADSL fail empresas.La wiring for RTB voice and data transmission, which can be done together (as with ISDN). This is achieved by establishing three independent channels on the same telephone line Standard: Two high-speed channels, one for receiving and one for sending data, Yun third channel for normal communication voz.El name "asymmetric" carrying the ADSL because the bandwidth of each data channel is different, reflecting the fact that most traffic between a user and the Internet network are discharges. 

Wired: Using light instead of electrical signals can encode a much larger amount of information, playing with variables such as the wavelength and intensity of the light signal. Furthermore, the light signal can be transported free of noise problems affecting electromagnetic waves. 
The cable connection using a fiber optic cable for data transmission between nodes. From the node to the end user's home coaxial cable, which serves many users (between 500 and 2000, typically), so the bandwidth available to each user's variable is used (depends on the number of users connected the same node) usually range from 2 Mbps to 50 Mbps. 
From the physical point of view, the fiber optic network requires a new and expensive infrastructure, explaining that still is not available everywhere. 



Satellite connection: The connection system which is commonly used is a hybrid satellite and telephone. Keep a digital satellite dish installed, dial-up Internet (using a PSTN, ISDN, ADSL or cable modem), a receiving card for PC, special software and a subscription to a provider TV.The netizen sends its emails and request for the web pages, which consumes very little bandwidth, using a regular modem, but the reception is caused by a satellite, whether software, videos or any other material that occupy many megabytes. The download speed via satellite can be placed in optimal cases around 400 Kbps. 


Wireless Networking: Wireless or wireless networks differ from all previously seen in the physical media used to convey information. They use infrared light signals or radio waves instead of cables to transmit information. 
With wireless technology is typically implemented local area network (LAN) q is connected via a router to the Internet, and is known by the name of WLAN (Wireless LAN). 
To connect a computer to a WLAN requires a WiFi device installed on your computer, which provides a physical interface and link layer between the operating system and the network. At the other end there will be an access point (AP) that, in the case of typical WLANs, is integrated with the router that provides access to the Internet, typically using a wired connection does use. 

When radio waves are used, they use a range of frequencies denormalized, or free use, within which can be chosen. Its range varies depending on the frequency used, but typically ranges between 100 and 300 meters, in the absence of obstacles físicos.Existe a wireless standard, WiMAX, whose reach extends to 50 km, which can achieve higher transmission speeds to 70 Mbps and capable of connecting 100 users simultaneously. Although not yet marketed use, its implementation would obviously compete with cable regarding bandwidth and number of users served.



Mobile Phone Connections : We speak of connections for mobile phones (as opposed to connections through mobile phones, which act as mobile modem) to designate the type of specific technologies for accessing Internet browsing from the mobile device itself. 
The (Global System Mobile) GSM system was the first standardized mobile communication system. This is a system that uses radio waves as a transmission medium (the frequency to 900 MHz was initially agreed but were later extended to 1800 MHz). Today, the bandwidth reaches 9.6 Kbps. GSM provides circuit connections; ie when you want to establish a communication line reserves (and therefore the bandwidth available to the operator for communications), and it remains occupied until the communication is terminated. An evolution of this system was to use, instead, a connection packet, similar to that used in Internet. This standard has evolved known as GPRS (General Packet Radio Service) is more oriented (and better suited) to GSM data traffic. For example, allows billing based on the amount of data sent and received, and not according to connect time.


VIDEO CONNECTING TO INTERNET