A PAN could have computers, phones, video game consoles, or other peripheral devices. They are common inside homes and small office buildings. Bluetooth is the most commonly known wireless PAN. A metropolitan-area network is a computer network that spans across a city, small geographical area, or business or college campus. A LAN usually consists of a solitary building or area.
A MAN can cover several square miles, depending on the needs of the organization. Large companies, for example, may use a MAN if they have a spacious campus and need to manage key components, such as HVAC and electrical systems. A wide-area network covers a very large area, like an entire city, state, or country. In fact, the internet is a WAN. Cellular services are the most commonly known wireless WANs. A Wi-Fi based wireless network sends signals using radio waves cellular phones and radios also transmit over radio waves, but at different frequencies and modulation.
This is called a Service Set Identifier SSID and it is what users see when they look at the list of available networks on their phone or laptops. The AP advertises this by way of transmissions called beacons. A client device receives the beacon transmitted by the AP and converts the RF signal into digital data, then that data is passed along to the device for interpretation.
If the user wants to connect to the network, it can send messages to the AP trying to join and when security is enabled providing the proper credentials to prove they have the right to join. If either of these fail, the device will not successfully join the network and will be unable to further communicate with the AP. Data from the client or from the AP to the client is converted from digital data into an RF modulated signal and transmitted over the air.
When received, this is de-modulated, converted back to digital data, and then forwarded along to its destination often the internet or a resource on the larger internal network. Wi-Fi communication is only approved to transmit on specific frequencies, in most parts of the world these are the 2. These frequency bands are not the same that cellular networks use, so cell phones and Wi-Fi are not in competition for use of the same frequencies. However that does not mean that there are not other technologies that can operate in these bands.
In the 2. If several Wi-Fi devices all want to connect to a network, they can all use the same AP. This offers a convenient solution, making Wi-Fi extensible into environments where coverage for many users is needed. There are also some APs that are weatherproof, designed to be mounted outdoors.
An Access Point is similar to a person on stage, addressing an audience or crowd - they are providing the information for everyone else.
Those audience members can ask questions of the person on the stage, and receive a response. Ad-Hoc Node Mesh. Some wireless devices laptops, smart phones, or wireless routers support a mode called Ad-Hoc.
This allows those devices to connect together directly, without an Access Point in-between controlling the connection. This forms a different type of network - in Ad-Hoc mode, all devices are responsible for sending and receiving messages to the other devices - without anything else in between.
In an Ad-Hoc network, every device must be in this role, and using the same configuration to participate. An Ad-Hoc or Mesh node is similar to an individual in a group or roundtable discussion. They can take equal part in the conversation, raising their hand when they want to speak so the others will listen.
If someone at the end of the table cannot hear, one of the individuals in-between can repeat the original message for the listener. Quick Activity: Describe the differences in the two example networks below.
What are the roles and relationships between the different colored nodes in the networks? Are there places or times in a social situation where you are in an Access Point or Client situation? Are there places or times when you are in an Ad-Hoc situation? From the roles above, you can see that Clients always need to connect to an Access Point, and Mesh nodes all connect to each other. It should also be noted that due to how Wi-Fi is designed, this also prevents different roles from connecting to each other as well.
Treat the three types of roles above - Clients, Access Points, and Ad-Hoc nodes - as the building blocks for large networks. Below are several examples that demonstrate how devices configured for different roles can be used. Wireless networks used in your home or office are generally a combination of a router and a wireless Access Point AP. In many home networks, or small office networks, the router and AP may be combined into a single device.
This is usually just called a wireless router. In large office scenarios, there may be several AP devices spread throughout the building to provide more even wireless coverage, connected back to the router through long Ethernet cables. Wireless networks can be used to connect distant buildings or areas. It usually requires very focused antennas - such as a dish antenna - that can send a narrow beam in a specific direction. This is discussed in Learn Wireless Basics - so go there for more details on how that works.
The name describes the concept: two points are connected together, and nothing else. This requires two wireless devices: one configured as an Access Point; the other configured as a Client.
In the example below, two wireless devices are configured to create a point-to-point link. Here we have another example of a point-to-point link, but where the routers have dish antennas for greater link distance.
This could look like the network below, where an AP mounted on a tower is able to connect with a Client device in a home very far away, since the dishes are facing one another. In both of these examples, there are just two wireless devices linked together - and the antennas determine the range at which they can connect. The more focused the signal, the further the point-to-point link can reach. As the distance between the devices grow, it is more an more important to focus the signal with antennas - at both ends of the connection.
Otherwise one end may hear the other, but not be loud enough to be heard! The radios used for WiFi communication are very similar to the radios used for walkie-talkies, cell phones and other devices.
They can transmit and receive radio waves, and they can convert 1s and 0s into radio waves and convert the radio waves back into 1s and 0s. But WiFi radios have a few notable differences from other radios:. WiFi uses Other WiFi radios can transmit on any frequency band. Or they can "frequency hop" rapidly between the different bands.
Frequency hopping helps reduce interference and lets multiple devices use the same wireless connection simultaneously. As long as they all have wireless adapters, several devices can use one router to connect to the internet.
This connection is convenient, virtually invisible and fairly reliable; however, if the router fails or if too many people try to use high-bandwidth applications at the same time, users can experience interference or lose their connections, although newer, faster standards like You may be wondering why people refer to WiFi as The The IEEE sets standards for a range of technological protocols, and it uses a numbering system to classify these standards.
A WiFi hot spot is simply an area with an accessible wireless network. The term is most often used to refer to wireless networks in public areas like airports and coffee shops. Some are free and some require fees for use, but in either case they can be handy when you are on the go.
You can even create your own mobile hot spot using a cell phone or an external device that can connect to a cellular network. And you can always set up a WiFi network at home.
If you want to take advantage of public WiFi hot spots or your own home-based network, the first thing you'll need to do is make sure your computer has the right gear. Most new laptops and many new desktop computers come with built-in wireless transmitters, and just about all mobile devices are WiFi enabled.
If your computer isn't already equipped, you can buy a wireless adapter that plugs into the PC card slot or USB port. Desktop computers can use USB adapters, or you can buy an adapter that plugs into the PCI slot inside the computer's case. Many of these adapters can use more than one Once you've installed a wireless adapter and the drivers that allow it to operate, your computer should be able to automatically discover existing networks.
This means that when you turn your computer on in a WiFi hot spot, the computer will inform you that the network exists and ask whether you want to connect to it. If you have an older computer, you may need to use a software program to detect and connect to a wireless network.
Being able to connect to the internet in public hot spots is extremely convenient. Wireless home networks are convenient as well. They allow you to easily connect multiple computers and to move them from place to place without disconnecting and reconnecting wires.
In the next section, we'll look at how to create a wireless network in your home. If you already have several computers networked in your home, you can create a wireless network with a wireless access point. If you have several computers that are not networked, or if you want to replace your ethernet network, you'll need a wireless router.
This is a single unit that contains:. A wireless router allows you to use wireless signals or ethernet cables to connect your computers and mobile devices to one another, to a printer and to the internet. Most routers provide coverage for about feet If your home is very large, you can buy inexpensive range extenders or repeaters to increase your router's range.
As with wireless adapters, many routers can use more than one Normally, A wireless network allows devices to stay connected to the network but roam untethered to any wires. Access points amplify Wi-Fi signals, so a device can be far from a router but still be connected to the network.
When you connect to a Wi-Fi hotspot at a cafe, a hotel, an airport lounge, or another public place, you're connecting to that business's wireless network.
A wired network uses cables to connect devices, such as laptop or desktop computers, to the Internet or another network.
A wired network has some disadvantages when compared to a wireless network. The biggest disadvantage is that your device is tethered to a router. The most common wired networks use cables connected at one end to an Ethernet port on the network router and at the other end to a computer or other device. Previously it was thought that wired networks were faster and more secure than wireless networks.
But continual enhancements to wireless network technology such as the Wi-Fi 6 networking standard have eroded speed and security differences between wired and wireless networks. To create your wireless network, you can choose between three types of deployment: centralized deployment, converged deployment, and cloud-based deployment.
Need help figuring out which deployment is best for your business? Talk to an expert.
0コメント