Wifi 11n

In addition to these five universal Wi-Fi standards, some other related wireless networking technologies offer slightly different values:

The 802.11 family of wireless networking standards, from 802.11a to 802.11az

Home and business owners looking to purchase networking equipment are faced with a wide range of choices. Many products meet wireless standards 802.11a, 802.11b/g/n and/or 802.11ac, which are all collectively referred to as Wi-Fi technologies. Bluetooth and various other wireless (but not Wi-Fi) technologies also pervade the market, each designed for specific networking applications.

Let's say right off the bat that 801.11aj, for example, is the latest approved standard. The protocol was approved in May 2018. However, just because a standard is approved doesn't mean it's available to you or that it's the standard you need for your particular situation. Standards are constantly being updated, just like the way you update the software on your smartphone or on your computer.

What is the 802.11 standard

In 1997, the Institute of Electrical and Electronics Engineers created the first WLAN standard. They called it 802.11 в after the name of the group created to oversee its development. Unfortunately, 802.11 only supported a maximum network bandwidth of 2 Mbps – too slow for most modern applications. For this reason, conventional 802.11 wireless products are no longer made. However, a whole family has grown out of this original standard.

The best way to look at these standards is to look at 802.11 as a foundation, and all other iterations as building blocks on that foundation that aim to improve both small and large aspects of the technology. Some of the building blocks are minor, and others are quite large.

Below is a brief overview of the most recently approved iterations, described from the newest to the oldest. Other iterations – 802.11ax, 802.11ay and 802.11az – are still in the approval process.

Connecting and Configuring a Chinese 802.11n Wi-Fi Adapter

First I'll show you how to get around the complicated process of finding the necessary driver. Maybe we will be lucky and the computer will make friends with the adapters without much dancing with tambourine 🙂 .

Let's take the 802.11n adapter from EDUP as an example. I have one of these, so everything is proven by my own experience. There is also "easy idea wifi N", but everything there is identical to EDUP. Checked it out. So, connect the adapter to the computer. You can plug it directly into the USB port.

Or you can use a USB extension cable. You can use it to move the adapter higher for better reception. Just don't use a long extension cord, it might be a problem.

Of course, much depends on the operating system installed on your PC. Again, in my case, both adapters worked immediately in Windows 10. In Device Manager they are detected as 802.11n USB Wireless LAN Card.

If the computer does not see the adapter, or rather can not automatically install a driver for it, then try to install the driver from the disk, which should be included. I had a disk with each adapter.

Usually the disk contains drivers for Windows, Mac OS and Linux. If there is a Setup.exe file on there, all you have to do is run it and follow the installation instructions. And if it's just a collection of different files in folders, you need to install it through the Device Manager. I will show you how to do that in the article below.

How do I find the driver for an unknown 802.11n WLAN Wi-Fi adapter?

I connected my Chinese EDUP USB adapter to my Windows 7 PC, and of course I saw the message "The software for the device has not been installed. 802.11n WLAN – Could not find the driver. This can happen even in Windows 10. Ten does not always automatically install software.

The solution to this problem is to search for the driver by "Hardware ID". Now I will show you everything in detail. If there was a CD with your WLAN receiver, you can try to install the software from there. If not, follow the instructions.

Right away I will answer the popular question: "How can I download the driver if there is no Internet on the computer? The adapter does not work yet, I can not connect to the Internet. It is clear, and it seems to me that there are no options here. Either connect the computer to the Internet via cable and configure the wireless adapter, or download the necessary drivers on another computer. There is no other way.

Go into the device manager. You can open it in different ways. Through a search, via Properties in My Computer, or with the command devmgmt.mscwhich should be entered in the window "Run", which in turn can be opened by pressing Win + R.

Under "Other Devices" there should be an unknown device "802.11 n WLAN" with a yellow exclamation mark. This is our adapter. We need to find out the "Hardware ID". To do this, open its "Properties".

Next, go to the tab "Information" and from the list choose "Hardware ID" and copy the first line. If you will look for the driver on another computer, you can save it in a text document.

It is necessary to paste the copied line into the search field. Most likely you will also need to shorten it.

Backward compatibility switching

802.11n provides backward compatibility for devices in a network using earlier versions of Wi-Fi, this adds a significant overhead to any exchanges, thereby reducing the data transfer capacity. To provide the maximum data transfer speeds when all devices in the wireless local area network are operating on the 802.11n standard, the backward compatibility feature can be removed.

When earlier devices enter the wireless LAN, the backward compatibility overhead and features are re-introduced. As with 802.11g, when earlier devices enter a network, the operation of the whole wireless LAN is considerably slowed. Therefore operating a net in 802.11n only mode offers considerable advantages.

In view of the features associated with backward compatibility, there are three modes in which an 802.11n access point can operate:

By implementing these modes, 802.11n is able to provide complete backward compatibility while maintaining the highest data rates. These modes have a significant impact on the physical layer, PHY and the way the signal is structured.

11n signal / OFDM implementation

This version of the Wi-Fi wireless LAN standard uses OFDM to provide the various parameters required.

Note on OFDM:

Orthogonal Frequency Division Multiplex, OFDM is a form of signal format that uses a large number of close spaced carriers that are each modulated with low rate data stream. The close spaced signals would normally be expected to interfere with each other, but by making the signals orthogonal to each other there is no mutual interference. The data to be transmitted is shared across all the carriers and this provides resilience against selective fading from multi-path effects.

The way that OFDM has been used, has been tailored to enable it to fulfil the various requirements for 802.11n.

To achieve this, two new formats are defined for the PHY Layer Convergence Protocol, PLCP, i.e. the Mixed Mode and the Green Field. These are called High Throughput, HT formats. In addition to these HT formats, there is also a legacy duplicate format. This duplicates the 20MHz legacy packet in two 20MHz halves of the overall 40MHz channel.

The signal formats are changed according to the mode in which the system is operating:

Legacy Mode: This may occur as either a 20 MHz signal or a 40 MHz signal:

• 20 MHz: In this mode the 802.11n signal is divided into 64 sub-carriers. 4 pilot signals are inserted in sub-carriers -21, -7, 7 and 21. In the legacy mode, signal is transmitted on sub-carriers -26 to -1 and 1 to 26, with 0 being the centre carrier. In the HT modes signal is transmitted on sub-carriers -28 to -1 and 1 to 28.
• 40 MHz: For this transmission two adjacent 20MHz channels are used and in this instance the channel is divided into 128 sub-carriers. 6 pilot signals are inserted in sub-carriers -53, -25, -11, 11, 25, 53. Signal is transmitted on sub-carriers -58 to -2 and 2 to 58.

WiFi network types

Although most people are familiar with the basic way that a home Wi-Fi network might work, it is not the only format for a WiFi network.

Essentially there are two basic types of Wi-Fi network:

• Local area network based network: This type of network may be loosely termed a LAN based network. Here a Wi-Fi Access Point, AP is linked onto a local area network to provide wireless as well as wired connectivity, often with more than one Wi-Fi hotspot. The infrastructure application is aimed at office areas or to provide a "hotspot". The office may even work wirelessly only and just have a Wireless Local Area Network, WLAN. A backbone wired network is still required and is connected to a server. The wireless network is then split up into a number of cells, each serviced by a base station or Access Point (AP) which acts as a controller for the cell. Each Access Point may have a range of between 30 and 300 metres dependent upon the environment and the location of the Access Point. More normally a LAN based network will provide both wired and wireless access. This is the type of network that is used in most homes, where a router which has its own firewall is connected to the Internet, and wireless access is provided by a Wi-Fi access point within the router,. Ethernet and often USB connections are also provided for wired access.
• Ad hoc network: The other type of Wi-Fi network that may be used is termed an Ad-Hoc network. These are formed when a number of computers and peripherals are brought together. They may be needed when several people come together and need to share data or if they need to access a printer without the need for having to use wire connections. In this situation the users only communicate with each other and not with a larger wired network. As a result there is no Wi-Fi Access Point and special algorithms within the protocols are used to enable one of the peripherals to take over the role of master to control the Wi-Fi network with the others acting as slaves. This type of network is often used for items like games controllers / consoles to communicate.

WiFi hotspots

One of the advantages of using WiFi IEEE 802.11 is that it is possible to connect to the Internet when out and about. Public WiFi access is everywhere – in cafes, hotels, airports, and very many other places.

Sometimes all that is required is to select a network and press the connect button. Others require a password to be entered.

When using public Wi-Fi networks it is essential to act wisely because it is very easy for hackers to gain access and see exactly what you are sending: user names, passwords, credit card credentials, etc. If the Wi-Fi network does not use encryption, then all the data can be seen by potential hackers.

In order to develop a common standard for the implementation for Wi-Fi hotspots a standard known as Hotspot 2.0 was developed. This is implemented by a number of operators when deploying Wi-Fi hotspots.

Compatibility with Draft-N versions

Virtually all existing 802.11 Draft-N supported devices can be upgraded to the final specification; this capability was built in from the beginning. Eventually all future 802.11n devices will be compatible with previously Draft-N-marked equipment.

According to the IEEE, 802.11n networks are already quite widespread. As of September 2009 more than 1 million draft-n devices had been sold by the day. Intel supports this standard in the Intel Centrino mobile platform.

ABI Research predicts that 802.11a/g is currently the most common bundle used in hotspots. It accounts for 84% of all sales. It is expected that by 2012. sales of 802.11n access points will overtake those of 802.11a/g devices, accounting for more than 60% of all shipments. By 2010 the revenue from 802.11n devices is expected to be double that of legacy 802.11n devices.

History

The standard has been in development since 2002. In 2006 a first draft of the specification was released which allowed companies to integrate support for the standard into notebooks and to manufacture the corresponding access points, routers, and other equipment. However, the draft status of the standard forced them to use the phrase "802.11 Draft-N" ("802.11n Draft"). After the official approval of the standard the prefix "Draft" is no longer required.

A total of over 400 people from semiconductor and networking companies, service providers, and educational institutions in more than 20 countries participated in the development of the standard.

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