Telecommunications, the Internet, and Wireless Technology
WHAT IS A COMPUTER NETWORK?
A network interface card is a type of network interface device found in every computer connected to the network (NIC). These days, the motherboard of the majority of personal computers includes this card. In the case of wireless local area networks and cell phones, the connection medium for connecting network components can be a radio signal, coaxial cable, or telephone wire (Wi-Fi networks).
The network operating system (NOS) organizes network resources, handles network traffic, and routes communications. It can be located on each computer in the network or it can be primarily located on a computer that serves as the server for all network applications. A server computer is a computer connected to a network that serves up Web sites, stores data, and houses the network operating system for client computers (and hence controlling the network).
In most networks, there is also a switch or hub that works as a connection point between the computers. Hubs are very basic network connectors that send a packet of data to every other connected device. A switch is more intelligent than a hub and has the ability to filter and forward data to a specific network location.
Networking and Communication Trends
Telephone networks and computer networks were the two primary types of networks utilized by businesses in the past. In the past, voice communication was handled by telephone networks, and data traffic was managed by computer networks. Throughout the 20th century, voice transmission technologies (hardware and software) were used to build telephone networks by
telephone companies, which nearly invariably ran as globally regulated monopolies. To send data between computers in various locations, computer companies initially established computer networks.
Telephone and computer networks are merging into a unified digital network using standardized hardware and software based on the Internet thanks to ongoing telecommunications deregulation and information technology innovation. In addition to voice service, modern telecommunications companies now provide data transmission, Internet access, cellular telephone service, and television programming. Internet telephone and restricted video services have been added to computer networks. More and more, Internet technology is the foundation for all of these voice, video, and data transactions.
Networks for voice and data communications have both improved in terms of speed, power, portability, and affordability. For instance, in 2000, the average Internet connection speed was 56 kilobits per second, but today, more than 60% of Internet users have high-speed broadband connections offered by telephone and cable TV providers that can transfer data at a rate of 1 to 15 million bits per second.
WHAT IS THE INTERNET?
The Internet has developed into the largest public communication network in the world, outpacing the international telephone network in size and reach. With the ability to connect millions of unique networks worldwide, it is also the largest client/server computing and internetworking implementation in the world. This international network was started by the U.S. Department of Defense in the early 1970s as a way to connect scientists and university teachers all around the world.
The majority of homes and small businesses use an Internet service provider to connect to the Internet. An Internet service provider (ISP) is a for-profit company with a constant Internet connection that provides retail consumers with short-term access. For ISP Internet connections, there are many different services available. Broadband connections have mostly replaced traditional telephone lines and modems. These broadband services are offered by digital subscriber line (DSL), cable, satellite Internet connections, and T lines.
Internet Addressing
The TCP/IP networking protocol suite, which was previously covered in this chapter, is the basis of the Internet. Every computer connected to the Internet has a specific IP address, which is now a 32-bit number represented by four strings of digits from 0 to 255 separated by periods. For instance, www.microsoft.com’s IP address is 207.46.250.119.
Using the TCP protocol, a message is first divided into packets before being sent across the Internet to another user. The destination address is included in each packet. In order to reach a specific computer with a known address, the packets are then transferred from the client to the network server, and then on to as many more servers as required. The packets are put back together to form the original message at the destination address.
The Domain Name System
The Domain Name System (DNS) transfers domain names to IP addresses because strings of 12 numbers would be extremely difficult for Internet users to memorize. The English-sounding name that corresponds to each computer’s individual 32-bit IP address when it is linked to the Internet is called the domain name.
DNS servers keep a database with a mapping between IP addresses and the related domain names. Users just need to specify a computer’s domain name in order to access it through the Internet.
THE WIRELESS REVOLUTION
Do you use your cell phone for downloading music, sending text messages, or capturing and sending pictures and sending them? Do you use your laptop to connect to the Internet in the library or at school? You are a member of the wireless revolution if so! Small handheld devices, laptops, and cell phones have developed into portable computing platforms that enable you to carry some of the computing tasks you formerly performed at your desk.
Businesses may more easily stay in touch with clients, vendors, and staff thanks to wireless communication, which also offers more flexible work scheduling options. New products, services, and distribution methods have been made possible by wireless technology.
Cellular Systems
Cellular networks from earlier generations were built primarily for voice communication and a small amount of data transmission in the form of text messages. Third-generation (3G) cellular networks, which wireless carriers now offer, are more potent cellular networks with transmission speeds ranging from 144 Kbps for mobile users, like those in a car, to 2 Mbps or more for stationary users. This makes 3G networks excellent for wireless broadband Internet access since it allows for the simultaneous transmission of speech, rich media, and video. Today’s cell phones feature 3G capabilities on a large number of them.
4G networks, the next step in wireless communication, are completely packet switched, capable of 100 Mbps transmission speed (which, under ideal situations, can reach 1 Gbps), with premium quality, and very secure. Users will have access to voice, data, and HD streaming video whenever and wherever they want. Currently, pre-4G technologies include mobile WiMax and Long Term Evolution (LTE).
Wireless Computer Networks and Internet Access
If you have a laptop, you might be able to use it as you go from table to table at the university library or from one room to another to access the Internet. For PCs, other wireless handheld devices, as well as cell phones, a variety of technologies offer high-speed wireless access to the Internet. Numerous regions that were not accessible via regular wired Internet services now have access to the Internet thanks to these new high-speed offerings.
RFID and Wireless Sensor Networks
a. Radio frequency identification
An effective technology for tracking the flow of goods along the supply chain is radio frequency identification (RFID) systems. RFID systems transmit radio signals to RFID readers over a short distance using tiny tags with embedded microchips that hold information about an object and its position.
The data is immediately sent to a computer for processing by the RFID readers across a network. Bar codes require line-of-sight contact to read, while RFID tags don’t. An item’s location, the place and time it was created, as well as other details about the item, such as its state during production, are all electronically programmed into the RFID tag. A microchip for storing the data is included within the tag. The tag’s remaining portion is an antenna that delivers information to the reader.
b. Wireless Sensor Networks
There are hundreds to thousands of connections in these networks. Wireless sensor devices must have very low power consumption and long-lasting batteries since they are left in the field for a long time without any maintenance or human involvement.
Monitoring environmental changes, traffic or military activity, protecting property, effectively operating and managing machinery and vehicles, creating security perimeters, keeping an eye on supply chain management, or observing chemical, biological, or radiological material are just a few applications where wireless sensor networks are useful.