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What is 802.11n Wi-Fi?
802.11n is the standard fixed for the wireless LAN or WLAN communications by the IEEE. This standard ensures that the speed of the wireless local area network is improved along with its reliability.
The 802.11n uses MIMO or Multiple Input and Multiple Output technology. It also uses a much wider radio frequency or RF channel. Both these technologies help it in providing a particular process called the frame aggregation. This helps in reducing the time taken between two successive transmissions.
KEY TAKEAWAYS
- There are lots of new and innovative features added in the IEEE 802.11n standard in order to better the wireless LAN connections and improve their performance.
- The working process of the 802.11n wireless standard is much simpler but faster. It basically utilizes two particular technologies such as MU-MIMO and OFDMA.
- The 802.11n standard offers better bandwidth and dual frequency bands that allows sending and receiving more data and is backward compatible.
- Higher power consumption, security requirements, interference issues, longer idle time, insufficient management control and the cost are a few major concerns.
Understanding 802.11n Wi-Fi
IEEE or the Institute of Electrical and Electronics Engineers has set a specific standard in the industry for local Wi-Fi networks.
This standard for communications was approved about a decade back in 2009.
This was the 802.11n standard which is an improvement of the existing standards namely:
- The 802.11a
- The 802.11b and
- The 802.11g wi-fi technologies.
However, the 802.11n was further developed to the 802.11ac standard in 2012, and later on in 2019, came the 802.11ax standard which is commonly known as the Wi-Fi 6 standard.
It is expected that the 802.11ay or the Wi-Fi 7 standard will be out soon.
The difference between each of these standards is that one is better, more reliable and faster than the previous standard.
Each of these are however, backwards compatible. Check out the differences between 802.11ac vs 802.11n Wi Fi.
The basic specification of the 802.11n standard as per IEEE ensures that the performance is much better than the previous versions.
The new standard also ensures that it keeps up with the growing need for speed by the consumers as well as the enterprises.
The IEEE 802.11n standard, when it came out first, provided a high level of functionality and performance. The main points included:
- Maximum data transfer rate of 600 Mbps
- RF band of 2.4 or 5 GHz
- DSSS, CCK, or OFDM modulation
- Channel width ranging between 20 and 40 MHz and
- 1 to 4 spatial streams.
In order to accomplish this, there were lots of new features included in the IEEE 802.11n standard for wireless LAN connections.
These innovative features ensured a higher performance and included:
- Implementation of MIMO or Memory Input and Memory Output
- Changes in the OFDM
- MIMO power saving
- A better antenna technology and
- A wider bandwidth for the channels.
The new standard also had a reduced backward compatibility support in specific circumstances.
This improves the data output. However, all these features added to the complexity and the cost of incorporating them in the chipset.
The backwards compatibility switching of 802.11n also adds a noteworthy overhead to the exchanges.
In addition to that, it was also responsible for a lowered data transfer ability.
However, this feature may be removed if you want to have the optimal speed for data transfer within the devices connected in the wireless network that are operating as per the 802.11n standard.
As for the access point, the 802.11n operates in three specific modes such as:
- The legacy mode for only the 802.11 a, b, and g
- The mixed mode for 802.11 a, b, g, and n and
- The greenfield mode only for the 802.11n standard that ensures maximum performance.
When all these modes are implemented in the 802.11n standard, it ensures comprehensive backward compatibility and at the same time the data rates are also maintained at the highest level.
Ideally, these modes impact significantly on the PHY, the physical layer of the device as well as the structure of the signal.
The different required parameters are provided by the OFDM or Orthogonal Frequency Division Multiplex feature of the 802.11n version of Wi-Fi wireless LAN standard.
This is actually a specific type of signal that uses closed space carriers in a large number and each of these carriers is modulated with a data stream of low rate. These close spaced signals help in:
- Faster data transfer rate without interfering with each of the packet transferred
- Creating orthogonal signals and
- Ensuring that there are no reciprocated interferences.
This further ensures that the data transferred is resilient and is shared by all the carriers.
This will also ensure that there is no selective fading of the data due to the multipath effects.
Here come the two formats that are specifically designed to define the PHY Layer Convergence Protocol or PLCP. These are:
- The green field and
- The Mixed Mode.
These two modes are referred to as the High Throughput or HT formats.
Another significant feature of the 802.11n standard is that the signal formats change according to the operating mode of the systems.
In addition to that, there is another legacy duplicate format.
This format doubles the 20 MHz legacy packet into two halves of 20 MHz that gives a 40 MHz channel overall.
Each of these modes come with its own characteristic attributes and affects the functionality in its own way. For example:
- The 20 MHz mode in the 802.11n signal has 64 sub-carriers out of which the -21, -7, 7 and 21 subcarriers have the four pilot signals inserted in them. However, in the legacy mode, these signals are transmitted through -26 to -1 and 1 to 26 subcarriers. Here, 0 is the center carrier. On the other hand, in the HT mode, the signal is transmitted through -28 to -1 and 1 to 28 subcarriers.
- The 40 MHz mode, on the other hand, uses two head-to-head 20 MHz channels for such transmission. Here the channel is further alienated into 128 sub-carriers. There are six pilot signals inserted in the sub-carriers -53, -25, -11, 11, 25, and 53. The signal, however, is transmitted on -58 to -2 and 2 to 58 subcarriers in frames that obey the legacy of 802.11a and 802.11g OFDM format.
- The mixed modes in 802.11n are actually overture compatible packets that are transmitted with the legacy 802.11a and g standard. As for the remaining packet, it comes in a MIMO training order format.
- The green field mode has high output packets that are not legacy compatible. This means that it does not contain any legacy element in it when it is transmitted. It is for this reason this mode or packet has a much higher output on the wireless LAN.
MIMO in 802.11n helps in carrying heavy loads of data at a higher rate on the wireless LAN.
This can be both in the domestic or in an office environment. This feature helps in utilizing the maximum bandwidth available.
MIMO is actually an advanced and more effective form of antenna technology.
There are multiple antennas used by it to enable the signals transmitted from different sources and paths to create a result of its reflections.
When separated, their ability helps in improving the overall data output as well as the signal to noise ratio.
Overall, it improves the performance level of the system.
How Does 802.11n Wi-Fi Work?
The 802.11n is much faster due to its simplified working process.
There are ideally two specific technologies that expedites its performance rate. These are:
- MU-MIMO and
- OFDMA.
MU-MIMO, or “Multi-User, Multiple Input, Multiple Output,” is a feature that you will get in almost all modern routers.
This feature and functionality are further enhanced by the 802.11n.
This is the technology that specifically helps the router to link with several devices at the same time.
This means that it will not broadcast only to one device first, and then to the next, and so on and so forth.
This helps in faster and all-round transmission of data.
The new OFDMA technology, on the other hand, stands for “Orthogonal Frequency Division Multiple Access.”
This technology helps in transmitting data to several devices at once.
This helps the router to transmit more data to your device at a time, in every transmission cycle.
The channel, on the other hand, also plays a significant role in controlling the communication your AP has with the client devices linked on your Wi-Fi network.
Most of the time, it is set to Auto in most of the APs by default.
The wider bandwidth of the channel ranging from 20 to 40 MHz will ensure a better performance.
This will help in connecting and supporting the 20 MHz legacy devices to your AP.
The four antennas in a high performance 802.11n equipment will handle four data streams at the same time ensuring a larger MIMO. Know extending wifi network.
The Pros of 802.11n Wi-Fi
1. Improved bandwidth
As compared to the previous standards, the bandwidth is significantly improved in 802.11n.
This ensures a far better performance and a faster transfer of data.
This ensures that the raw data transfer rate and output reaches 600 Mbps, which is ten times faster than the 802.11g standard.
2. Backward compatible
Since the 802.11n is entirely backward compatible, it helps in connecting legacy clients and also supports 802.11a, b and g standards.
3. Send and receive more data
With the use of technologies such as MIMO and two different data channels that can be used at the same time, you can send and receive more data.
The double data rate transfer ensures a better bonding between the channels.
This also increases the channel width from 20 MHz to 40 MHz of this standard.
4. Dual frequency bands
The ability of the 802.11n standard to operate on two different frequency bands of 2.4 GHz and 5 GHz, ensure more channels that results in an increase in its capacity.
The 2.4 GHz band enables better communication with the older pre-n equipment and the 5 GHz band enables communication with the different n products.
This eventually means a less crowded path for data transmission.
5. Signal recovery
The latest features of this standard also ensure a far better and faster signal recovery when the quality of the data transfer is significantly deteriorated.
In such situations the 802.11n standard devices will lower the data rate. This will in turn improve the quality of connection.
6. Security assurance
The standard postulates Wi-Fi Protected Access 2 or WPA2. This requires the data to be encrypted before transferring.
The use of the NIST Advanced Encryption Standard or AES provides more security to the data while being transferred.
7. Support for new generation devices
The design of the 802.11n standard makes it ready to use in most of the multimedia devices for the next generation.
With a more stable connectivity, it will help in streaming live music, playing high resolution videos, and playing high speed interactive games.
8. Battery life
The TWT or Target Wake Time function increases the battery life of the device, whether it is your mobile or any wi-fi enabled device.
While the access point is working, the wi-fi is suspended. It will wake up only when the next transmission is required to be made.
Since the wi-fi will be in sleep mode, it will save a considerable amount of power.
The Cons of 802.11n Wi-Fi
9. Expensive
Devices that support this standard are far more expensive as compared to the previous versions.
It is for this reason this standard of wi-fi connection is used in schools, hospitals and hotels.
10. Interference
Since the 802.11n standard uses multiple signals, there is a high chance of the signals as well as the system interfering with the 802.11b or 802.11g standard networks nearby.
11. Security requirements
You will need to use products that come with exceptional and latest security features.
This is because the 802.11n standard will allow transfer of data over greater distances.
This means that any intruder can gain access from far away to your network.
Moreover, the data being transferred at a quick rate will allow the intruder to gain access in much less time.
12. Power consumption
The power consumption will be more because it uses MIMO technology that significantly increases the required power to function by the internal hardware circuitry.
It also involves using a lot more receivers and transmitters that will once again use more power.
13. Idle time
There will be a long period of time when the device may sit idle or run at a very low speed.
This is because the data transmitted in this standard is often in ‘bursts.’
14. Network
Depending on the range, the extent of the network may be small.
This will pose a risk of interference of the signals more frequently due to the obstruction between the device and the router.
15. Reliability
The radio frequency channels that make the wi-fi networks work are typically prone to interference with the wi-fi signals.
This will make the performance of the network unreliable.
16. Inadequate management control
You will have lower control on the network of your company using this network standard.
This is because it will be easier for the employees to link their non-sanctioned devices with the network.
This means that they will use up a significant part of your bandwidth.
You may also not find them in their desk because the network will provide flexibility and they can work from anywhere.
Summing It up
The 802.11n standard has taken the wi-fi network standard to a new height.
This standard ensures that the features and functionality help the modern devices to transferrer data at a much faster rate and in a more secure manner.