Wireless network refers to any type of computer network that is not connected by cables of any kind. It is a method by which homes, telecommunications networks and enterprise (business) installations avoid the costly process of introducing cables into a building, or as a connection between various equipment locations. Wireless telecommunications networks are generally implemented and administered using radio communication. This implementation takes place at the physical level (layer) of the OSI model network structure.
ADVANTAGES OF WIRELESS NETWORKS
- Mobility: With a laptop computer or mobile device, access can be available throughout a school, at the mall, on an airplane, etc. More and more businesses are also offering free WiFi access (“Hot spots”).
- Fast setup: If your computer has a wireless adapter, locating a wireless network can be as simple as clicking “Connect to a Network” in some cases, you will connect automatically to networks within range.
- Cost: Setting up a wireless network can be much more cost effective than buying and installing cables.
- Expandability: Adding new computers to a wireless network is as easy as turning the computer on (as long as you do not exceed the maximum number of devices).
DISADVANTAGES OF WIRELESS NETWORKS
- Security: Be careful. Be vigilant. Protect your sensitive data with backups, isolated private networks, strong encryption and passwords, and monitor network access traffic to and from your wireless network.
- Interference: Because wireless networks use radio signals and similar techniques for transmission, they are susceptible to interference from lights and electronic devices.
- Inconsistent connections: How many times have you hears “Wait a minute, I just lost my connection?” Because of the interference caused by electrical devices and/or items blocking the path of transmission, wireless connections are not nearly as stable as those through a dedicated cable.
- Speed: The transmission speed of wireless networks is improving; however, faster options (such as gigabit Ethernet) are available via cables. If you are only using wireless for internet access, the actual internet connection for your home or school is generally slower than the wireless network devices, so that connection is the bottleneck. If you are also moving large amounts of data around a private network, a cabled connection will enable that work to proceed much faster.
TYPES OF WIRELESS NETWORKS
Wireless personal area networks (WPANs) interconnect devices within a relatively small area, that is generally within a person’s reach. For instance, both Bluetooth radio and invisible infrared light provides a WPAN for interconnecting a headset to a laptop.
A wireless local area network (WLAN) links two or more devices over a short distance using a wireless distribution method, usually providing a connection through an access point for Internet access. The use of spread-spectrum or OFDM technologies may allow users to move around within a local coverage area, and still remain connected to the network.
Fixed wireless technology implements point-to-point links between computers or networks at two distant locations, often using dedicated microwave or modulated laser light beams over line of sight paths. It is often used in cities to connect networks in two or more buildings without installing a wired link.
More and more networks are operating without cables, in the wireless mode. Wireless LANs use high frequency radio signals, infrared light beams, or lasers to communicate between the workstations, servers, or hubs. Each workstation and file server on a wireless network has some sort of transceiver/antenna to send and receive the data. Information is relayed between transceivers as if they were physically connected. For longer distance, wireless communications can also take place through cellular telephone technology, microwave transmission, or by satellite.
Wireless networks are great for allowing laptop computers, portable devices, or remote computers to connect to the LAN. Wireless networks are also beneficial in older buildings where it may be difficult or impossible to install cables.
The two most common types of infrared communications used in schools are line-of-sight and scattered broadcast. Line-of-sight communication means that there must be an unblocked direct line between the workstation and the transceiver. If a person walks within the line-of-sight while there is a transmission, the information would need to be sent again. This kind of obstruction can slow down the wireless network. Scattered infrared communication is a broadcast of infrared transmissions sent out in multiple directions that bounces off walls and ceilings until it eventually hits the receiver. Networking communications with laser are virtually the same as line-of-sight infrared networks.
Wireless mesh network
A wireless mesh network is a wireless network made up of radio nodes organized in a mesh topology. Each node forwards messages on behalf of the other nodes. Mesh networks can “selfheal”, automatically re-routing around a node that has lost power.
Wireless metropolitan area networks are a type of wireless network that connects several wireless LANs.
- WiMAX is a type of Wireless MAN and is described by the IEEE 802.16 standard.
Wireless wide area networks are wireless networks that typically cover large areas, such as between neighboring towns and cities, or city and suburb. These networks can be used to connect branch offices of business or as a public internet access system. The wireless connections between access points are usually point to point microwave links using parabolic dishes on the 2.4 GHz band, rather than omnidirectional antennas used with smaller networks. A typical system contains base station gateways, access points and wireless bridging relays. Other configurations are mesh systems where each access point acts as a relay also. When combined with renewable energy systems such as photo-voltaic solar panels or wind systems they can be stand alone systems.
A cellular network or mobile network is a radio network distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station. In a cellular network, each cell characteristically uses a different set of radio frequencies from all their immediate neighbouring cells to avoid any interference.
When joined together these cells provide radio coverage over a wide geographic area. This enables a large number of portable transceivers (e.g ., mobile phones, pagers, etc.) to communicate with each other and with fixed transceivers and telephones anywhere in the network, via base stations, even if some of the transceivers are moving through more than one cell during transmission.
Although originally intended for cell phones, with the development of smartphones, cellular telephone networks routinely carry data in addition to telephone conversations:
- Global System for Mobile Communications (GSM): The GSM network is divided into three major systems:the switching system, the base De station system, and the operation and te support system. The cell phone connects to the base system station which then connects to the operation and support bio station; it then connects to the switching station where the call is transferred to where it needs to go. GSM is the most common standard and is used for a majority of cell phones
- Personal Communications Service (PCS): PCS is a radio band that can be used by mobile phones in North America and South Asia. Sprint happened to be the first service to set up a PCS.
- D-AMPS: Digital Advanced Mobile Phone Service, an upgraded version of AMPS, is being phased out due to advancement in technology. The newer GSM networks are replacing the older system.
Wireless networks are much more susceptible to unauthorized use than cabled networks. Wireless network devices use radio waves to communicate with each other. The greatest vulnerability to the network is that rogue machines can “eves-drop” on the radio wave communications. Unencrypted information transmitted can be monitored by a third-party, which, with the right tools (free to download), could quickly gain access to your entire network, steal valuable passwords to local servers and online services, alter or destroy data, and/or access personal and confidential information stored in your network servers. To minimize the possibility of this, all modern access points and devices have configuration options to encrypt transmissions. These encryption methodologies are still evolving, as are the tools used by malicious hackers, so always use the strongest encryption available in your access point and connecting devices.
Three basic techniques are used to protect networks from unauthorized wireless use. Use any and all of these techniques when setting up your wireless access points:
- Encryption: Enable the strongest encryption supported by the devices you will be connecting to the network. Use strong passwords (strong passwords are generally defined as passwords containing symbols, numbers, and mixed case letters, at least 14 characters long).
- Isolation: Use a wireless router that places all wireless connections on a subnet independent of the primary private network. This protects your private network data from pass-through internet traffic.
- Hidden SSID: Every access point has a Service Set IDentifier (SSID) that by default is broadcast to client devices so that the access point can be found. By disabling this feature, standard client connection software won’t be able to “see” the access point.
Requirement for Wireless Connection
A) An operating system that supports wireless networking: The Windows 7 operating system fully supports wireless networking. For Windows Vista users, we recommend installing Windows Vista Service Pack 2 before setting up your wireless network. For Windows XP users, we recommend installing Windows XP Service Pack 3. Use Windows Update to check whether you need the service pack and to install it. Then Proceed as follows:
Click the Start button,
Click All Programs,
Click Windows Update,
Then click Check for updates.
Although the service packs for Windows Vista and Windows XP are not required for wireless networking, they can make things much easier and can help protect you against hackers, worms,and other Internet intruders.
B) A broadband (DSL or cable) Internet connection: To set up a wireless network, you need a broadband or high-speed Internet connection (not a dial-up connection) provided by an Internet service provider (ISP), usually for a monthly fee. Two common broadband technologies are Digital Subscriber Line (DSL) and cable technology. These require a DSL modem or a cable modem (often provided by your ISP). After you have an ISP and a modem, you’re ready to connect to the Internet.
C) A wireless router, a DSL modem, or a cable modem with built-in wireless networking support: The router converts the signals coming across your Internet connection into a wireless broadcast, sort of like a cordless phone base station. Newer DSL and cable modems come with integrated wireless networking capability and are called modem routers. If the modem router you received or purchased from your ISP already has wireless capability built in, you do not need to purchase a separate wireless router. Just follow the instructions provided by your ISP for activating your wireless connection.
D) A computer with built-in wireless networking support or a wireless network adapter: If you have a newer computer, you may already have built-in wireless capabilities. If this is the case, you don’t need a wireless network adapter. If your desktop or laptop computer does not have built-in wireless support, you need to purchase a network adapter to wirelessly connect your computer to your wireless router. If you need an adapter for a desktop computer, buy a USB wireless network adapter. If you have a laptop, buy a PC card-based network adapter. Make sure that you have one adapter for every computer on your network.
E) A copy of your router setup instructions: Before you begin setting up your wireless network, it’s a good idea to make sure that you have the copy of the setup instructions provided by the router manufacturer or your ISP. If you do not have a copy, visit the manufacturer’s website for get instructions on how to set up your router. All routers vary, and you may need to consult the instructions to set up your wireless network using your specific router.
After you have everything you need, follow these five steps to set up your wireless network.
1) Connect to the Internet: Make sure that your Internet connection and your DSL or cable modem are working. Your wireless network depends on this connection.
2) Connect your wireless router: These are the steps for connecting a standalone wireless router to your DSL modem or cable modem. If you have a modem router, follow your ISP’s instructions for connecting your network.
Since you will be temporarily disconnected from the Internet, print these instructions before you go any further.
First, locate your cable modem or DSL modem and unplug it to turn it off.
Next, connect your wireless router to your modem. Your modem should stay connected directly to the Internet. Later, after you’ve hooked everything up, your computer will wirelessly connect to your router, and the router will send communications through your modem to the Internet.
Next, connect your router to your modem:
i) If you currently have your computer connected directly to your modem: Unplug the network cable from the back of your computer, and plug it into the port labeled Internet, WAN, or WLAN on the back of your router.
ii) If you do not currently have a computer connected to the Internet: Plug one end of a network cable (included with your router) into your modem, and plug the other end of the network cable into the Internet, WAN, or WLAN port on your wireless router.
iii) If you currently have your computer connected to a router: Unplug the network cable connected to the Internet, WAN, or WLAN port from your current router, and plug this end of the cable into the Internet, WAN, or WLAN port on your wireless router. Then, unplug any other network cables, and plug them into the available ports on your wireless router. You no longer need your original router, because your new wireless router replaces it.
Next, plug in and turn on your cable or DSL modem. Wait a few minutes to give it time to connect to the Internet, and then plug in and turn on your wireless router. After a minute, the Internet, WAN, or WLAN light on your wireless router should light up, indicating that it has successfully connected to your modem.
3) Configure your wireless router: Using the network cable that came with your wireless router, you should temporarily connect your computer to one of the open network ports on your wireless router (any port that isn’t labeled Internet, WAN, or WLAN). If you need to, turn your computer on. It should automatically connect to your router.
Next, open Internet Explorer and type in the URL or address to configure your router.
NOTE: Do this on the computer that you are using to set up your wireless network. The computer automatically links you to the router’s page. If you type the router’s URL on a different computer, typing the address in the navigation bar will not take you to your router’s configuration page.
On the router configuration page, you might be prompted for a password. The address and password you use varies depending on what type of router you have, so refer to the instructions included with your router or on the manufacturer’s website.
Internet Explorer shows your router’s configuration page, along with the modem IP address and other information. Most of the default settings should be fine, but you need to configure three things:
i) Your wireless network name, known as the SSID: This name identifies your network, and it appears in a list of available wireless networks. You should change the default SSID that your ISP provided and give your network a unique name that none of your neighbors are using. This helps you identify your network, and it can help keep your wireless network secure by preventing it from overlapping with other wireless networks that might be using the default SSID.
ii) Wi-Fi Protected Access (WPA or WPA2), which can help protect your wireless network: It’s important to help secure your wireless network by setting up a network security key, which turns on encryption. With encryption, people can’t connect to your network without the security key, and all information sent across your network is encrypted so that only computers with the key to decrypt the information can read it. This can help prevent attempts to access your network and files without your permission. When you set up most routers (stand-alone routers and modem routers), you are asked to provide a pass phrase that the router uses to generate several keys. Make sure that your pass phrase is unique and long (you don’t need to memorize it). Some routers and modem routers now come with a function called Quick Security Setup (or QSS) that automatically issues you a key when you press a button on the router.
iii) Your administrative password, which controls your wireless network: Just like any other password, it should not be a word that you can find in the dictionary, and it should be a combination of letters, numbers, and symbols. Be sure to save a hard copy and a digital copy of this password, too, because you’ll need it if you ever have to change your router’s settings.
The exact steps you follow to configure these settings will vary depending on the type of router you have. After each configuration setting, be sure to click Save Settings, Apply, or OK to save your changes.
Now, before connecting your computers and devices to the network, you should disconnect the wireless network cable from your computer.
4) Connect your computers, printers, and other devices to the wireless network: If the computer or device you want to add does not have built-in wireless network support, plug the network adapter into your USB port and place the antenna on top of your computer (in the case of a desktop computer) or insert the network adapter into an empty PC card slot (in the case of a laptop). Windows automatically detects the new adapter and may prompt you to insert the CD that came with your adapter. The on-screen instructions guide you through the configuration process.
5) Share files, printers, and more: Now that your computers and devices are connected, you can begin sharing files, printers, games, and much more. One of the top reasons for setting up a home network is to share a printer. Another is to share files. The steps for doing this, however, aren’t always obvious, so here are instructions to get you started.