The Internet
Area networks are subdivided depending on the distance devices such as computers, printers, speakers, etc. can communicate with each other. Those only capable of short distances are local area networks (LAN). Metropolitan area networks (MAN) encompass much larger ranges such as cities. Wide area networks (WAN) can connect computer devices globally and is referred to as the internet requiring substantial computing and transmission capabilities offered by internet service providers (ISPs).
To date there are only two ways to interconnect devices, either hard wired or by using radio waves. Hard wired goes way back to the old telegraph days evolving to the present day ethernet connecting several computer systems together to form a local area network. Ethernet is covered in IEEE 802.3. Twisted pair wires and coaxial cables have been made more efficient with the advent of CAT 5, CAT 6 and so on now capable of more than 10 gigabits per second.
An analog signal is basically a sine wave with information made possible by a variation in its amplitude or difference in its energy and variation in its frequency or difference in the time taken for the wave to complete its cycle. What we see and hear is an analog signal. Just as telegraphs used dots and dashes interpreted by Morse Code computers have become much faster and more efficient using a series of pulses using 0s and 1s, either the presence of a voltage or not. 10 GBs is one thousand million 0s an 1s transferred each second. Fiber optical cable using tiny glass or plastic threads transmit light instead of voltage making these pulses even faster and capable of maintaining integrity over much larger distances. Fiber optic cable now lay at the bottom of oceans making communication between countries around the world possible.
Routers are not the same as modems. Routers interconnect several devices including the modem together to form a network. Every computer, printer, TV, speaker system, modem, etc. has a unique number. A router determines the address of the device data is to be sent to and ensures information is sent back to the address of the devise it is communicating with and to prohibit transmission at the same time by more than one device. This prevents the printer from communicating with the speaker system for example. Routers route traffic between the devices and modem communicating with the internet.
With the advances of satellites, we depend more on wireless communication. Our satellite TVs and cell phones are wireless using radio waves. As of now radio waves use analog technology by varying the amplitude and frequency of sine waves. Maybe not as efficient as ethernet but more convenient. That’s where modems come in, converting information on radio waves into digital pulses used by computers. Wide area networks, or the internet, use analog radio waves changed to digital signals by modems required by computers in a local area network (LAN). Modems do this by modulating and demodulating analog and digital signals back and forth depending on whether the operator is sending or receiving information.
Analog radio waves are usually classified as either VHF or UHF. The number of sine waves an analog signal has a second is measured in hertz. Very high frequencies (VHF) operate between 30 to 300 million hertz (MHz) mostly used for radios. Televisions, cell phones, etc. require much more information in a quick period of time and use ultra-high frequencies operating between 300 MHz and 3 gigahertz (GHz).
Wi-Fi exchanges data between digital devices by using UHF radio waves. It links computers, phones, televisions, speakers, printers and so forth in local area networks. A hot spot is where the distance between devices is close enough to allow the radio waves between them to be received efficiently. Repeaters extend the range of wireless local area networks (WLAN). The Wi-Fi Alliance incorporates about a thousand companies globally and is addressed by the Institute of Electrical and Electronic Engineers in IEEE 802.11. Roaming occurs between overlapping hot spots.
Bluetooth is also wireless using ultra high frequencies much like Wi-Fi but is only effective for very short distances up to about 30 feet to create a personal area network (PAN). It is discussed in IEEE 802.15.1 and is controlled by the Blue Tooth Special Interest Group (SIG) which owns its trademark. For Bluetooth to work a special transceiver chip must be embedded in each device intended to communicate with each other.
Although used extensively to access the world wide web the internet is different. The internet interconnects computer networks around the world and can be used to exchange other data such as email, sharing files including videos, music, and messaging for instance. The internet has no dominant administration and is supported by the Internet Engineering Task Force (IETF).
One definition of protocols by Merriam-Webster is a code prescribing strict adherence to correct etiquette procedure. In the computer world protocols are a set of rules for arranging and processing data. Internet protocols include Internet Protocol Security (IPsec), Internet Control Messaging (ICMP), and Internet Group Management (IGMP). In addition there are protocols in transparent layers (TCP). HTTP is a Hyper Text Transfer Protocol. In the dictionary hyper is referred to as existing in a space of more than three dimensions. In the internet world this means a text does not need to be read from start to finish, but keywords can be accessed taking the reader to other pages or websites as far as that is concerned. These are called hyperlinks. HTTPS is basically HTTP that is encrypted. To encrypt is defined in the dictionary as a method of transforming a text into code to conceal its meaning. This prohibits hackers and malware unless they know the code. Updates may possibly be changing the encryption. HTTPS is somewhat similar to a third layer TLS/SSL: Transparent Layer Security or Secure Socket Layer. A fourth is UDP: User Diagram Protocol which is TCP with a fast response. HTML refers to Hyper Text Markup Language.
Open System Interconnection dictates how the internet works. OSI has layers for internet purposes. Osi includes physical, data link, network, transport, session, presentation, and application functions. Routers and modems have protocols as well to determine efficient network pathways to other networks.
Although websites are independent of the internet, the World Wide Web (www.) is a global collection of websites containing information accessed via the internet which can be interconnected and hyperlinked together. The world wide web requires each site to have a Uniform Resource Locator (URL) including a domain name and other information giving it a unique internet protocol (IP) address.
Eberling@www.thndrsns.com
