I will be focus only on IEEE 802.11ac & IEEE 802.11n.

The goal here is :

  • To achieve connection stability and not to achieve maximum data throughput.
  • To avoid a noisy wireless channel
  • The WiFi adapter will try to maintain a connection with only one WiFi router.

Generally, the default setting of the WiFi adapter is good for most conditions. In addition, you can do some settings according to your needs.

An uninterrupted internet connection by the ISP to the WiFi router is necessary for a stable connection between the WiFi adapter and the WiFi router. So make sure that your ISP is providing internet without any connections drops. 

  1. Avoid buying a Nano/Mini WiFi adapter. They don’t have a good range.
  2. If possible buy high gain Wifi USB Adapter.
  3. If possible buy an 802.11ac Wifi adapter. It uses 5Ghz frequency which is generally free from interference.
  4. To get better signal strength and speed you need to keep the WiFi adapter near the WiFi router. Try not to keep your computer far away from the WiFi router.
  5. Keep the WiFi adapter away from obstructions such as walls, metal objects, and other electrical equipment.
  6. The orientation of the WiFi adapter makes a lot of difference. Try orienting it to each of four directions and see which one works best for you.
  7. Keep the Wifi Router away from obstructions. Check the WiFi router manual for the correct orientation of the Wifi router antenna and do as instructed.
  8. You may need to do some settings in the WiFi router to get better stability.
  1. If possible use a USB extension wire. This will help in positioning the WiFi adapter in a better position.

2. Power Management Settings

Select Control Panel > Power Options

Click “Change plan settings

  • Click “Change advanced power settings

  • Select Wireless Adapter Settings > Power Saving Mode > Maximum performance.

 

 

3. Device Manager Settings

Select Control Panel > Device Manager.

  • Right-click on   Network Adapters > TP Link wireless USB adapter (Network adapter).
  • Select  Properties.

  • Select the Power Management Tab
  • Disable the check box labeled Allow the computer to turn off this device to save power.

Understanding various Wifi adapter jargons

VHT = Very High Throughput = 802.11ac
HT = High Throughput = 802.11n, 802.11a = Legacy

AP = Access Point, Wifi Router

BeamCap :

The Beamforming or Transmit Beam Forming (TxBF) technology produces the strong directional radiation pattern based on the strong correlation of the spatial channel and wave interference principle, making the main lobe of the radiation pattern adaptive to point to the wave direction. This technology improves the SNR, system capacity, and coverage range. Beamforming or TxBF is an optional feature in the 802.11n standard.

Beamforming includes explicit Beamforming and implicit Beamforming. Explicit Beamforming requires the receive end to send information about the received signal to an AP. The AP then adjusts the transmit power to the optimal value according to the signal information. This function increases the SNR of the receive end and improves the receiving capability. Implicit Beamforming allows an AP to automatically adjust the transmit power to increase the SNR of the receive end based on channel parameters without requiring the receive end to work with the AP. Currently, mainstream terminals do not support Beamforming.

The key benefits of beamforming are:
1. Reduce dead spots.
2. Deliver stable Wi-Fi connection for voice and HD video.
3. Better Wi-Fi throughput
4. Reduces unnecessary RF interference

802.11n supports implicit and explicit beamforming

802.11ac Supports only explicit Beamforming .

EnableAdaptivity : Will try to change frequency if it detects WiFi noise . Disable it, if you are relatively closer to the router OR if there are not many WiFi networks around

LDpcCap – The Low-Density Parity-Check (LDPC) is a code that enables or disables erroneous correction to reduce the probability of data loss in noisy channels.

StbcCap – Space Time Block Coding (STBC) is an 802.11n technique intended to improve the reliability of data transmissions. The data stream is transmitted on multiple antennas so the receiving system has a better chance of detecting at least one of the data streams.

  • On: The WiFi Access Point ( Wifi router)  transmits the same data stream on multiple antennas at the same time.
  • Off: The AP does not transmit the same data on multiple antennas.

Space time block coding (STBC) transmits multiple copies of one data flow in wireless communication. STBC uses many antennas to produce multiple receive versions of data, improving data transmission reliability. Among these data copies, optimal copies are combined to provide most reliable data. This redundancy increases the chance of using one or more copies of received data to correctly decode the received data. STBC combines all the copies of received signals to produce the useful data.

Space-Time Block Coding (STBC) can be used when the number of radio chains exceeds the number of spatial streams. In effect, STBC transmits the same data stream twice across two spatial streams so that a receiver that misses a data block from one spatial stream has a second shot at decoding the data on the second spatial stream. In effect, STBC takes the gains from MIMO and uses them nearly exclusively for increased range. A single encoding stream must take two radio chains for transmission, which means that a 2×2 MIMO device transmitting with STBC is effectively operating as a single-stream device. 802.11 interfaces include a step-down algorithm that selects slower and more reliable transmission rates; STBC can be used when the data channel is too poor to support one full stream per radio. In such environments, STBC is worth the 50% penalty on transmitted speed. When an STBC-enabled AP is serving mainly single-stream devices at long ranges, STBC is definitely worth considering.

Antenna Diversity Type
A wireless technique that uses multiple antennas to receive or transmit signals along different propagation paths to compensate for multi-path interference. Useful, if available.

Enable Adaptivity
HLDiffForAdaptivity
L2HForAdaptivity
“Adaptivity” seems to relate to ETSI’s (European Technology Standards Institute’s) adaptive frequency hopping requirements which are mostly for Bluetooth. I note that ALFA says your adapter contains some kind of anti-Bluetooth-interference device, which is probably what this is all about. It probably has a stripped-down Bluetooth radio that simply tells other Bluetooth radios to stop using the frequencies that its Wi-Fi radio is using.

Channel : Controls the channel your AP uses to communicate with client devices on your Wi-Fi network.
Most APs should have this set to Auto by default. We don’t recommend changing this setting unless you:

  • Have a good understanding of Wi-Fi channels
  • Know how to determine the least congested channel in your environment

Ideally, you would want to configure your AP to use a channel that isn’t being used by any of your neighbors.
Most of the time, Channel 1~14 (2.4GHz) are more congested than Channel 36~ (5GHz) but this can differ depending on the environment.
Some newer or higher-end APs are capable of operating at multiple bands (or channels) at the same time. For example, you may configure the AP to use Channel1@2.4GHz and Channel40@5GHz at the same time.

Channel Width or channel bandwidth

Controls the width of the channel (20 or 40MHz) your AP uses to communicate with client devices on your Wi-Fi network.

Wider channel width allows Improved maximum throughput.

For optimal performance and compatibility, enable support for all channel widths. Certain AP may allow 40MHz only mode which prevents legacy devices that support only 20MHz from connecting to the AP.

For band 5GHz, this setting uses 20/40/80/160 MHz depending on the wireless access point or router.

Fat channel intolerant
The setting communicates to surrounding networks that the Wi-Fi adapter isn’t tolerant of 40 MHz channels in the 2.4 GHz band. When disabled the adapter doesn’t send this notification.

Wireless Mode

Select which mode to use for connection to a WiFi network.

Auto :  Enables  all Wifi technology supported by the adapter. For optimal performance and compatibility, enable support for all wireless modes.

IEEE 802.11 a : The WiFi adapter will connect only to 802.11a networks only hosted at 5 GHz.

IEEE 802.11 a/n : The WiFi adapter will connect only to 802.11a/n  Wifi access point hosted at 5 GHz.

IEEE 802.11 a/n/ac : The WiFi adapter will connect only to 802.11a/n/ac  Wifi access point hosted at 5 Ghz.

IEEE 802.11 ac : The WiFi adapter will connect only to 802.11 ac Wifi access point hosted at 5 GHz.

IEEE 802.11 b : The WiFi adapter will connect only to 802.11b  Wifi access point hosted at 2.4 GHz.

IEEE 802.11 b/g :  The WiFi adapter will connect only to 802.11b or 802.11bg  Wifi access point hosted at 2.4 GHz.

IEEE 802.11 b/g/n :  The WiFi adapter will connect only to 802.11g/g/n  Wifi access point hosted at 2.4 GHz.

Dual Band 802.11 a/g : The WiFi adapter will connect only to 802.11a/g Wifi access point hosted at 5 Ghz & 2.4 GHz band .

Dual Band 802.11 a/b/g : The WiFi adapter will connect only to 802.11a/b/g networks hosted at 5 Ghz & 2.4 GHz band .

MIMO

Multiple input multiple output (MIMO) is an antenna system that consists of M transit antennas and N receive antennas. The MIMO technology allows spaces to become the resources used to improve performance and increases the coverage range of the wireless system.

The MIMO system generates multiple spatial flows with each antenna generating a maximum of one spatial flow. The single in single out (SISO) system sends or receives one spatial flow (one copy of signals) at a time. The MIMO technology allows multiple antennas to send and receive multiple spatial flows (multiple copies of signals) simultaneously and to differentiate the signals sent to or received from different spaces.

An 802.11n device supports up to 4×4 MIMO, a maximum of four spatial flows, with a rate of up to 600 Mbit/s. It supports a maximum of four streams and provides the maximum throughput of up to 600 Mbit/s.

802.11ac supports a maximum of eight streams ( 8×8 MIMO) and provides a maximum throughput of approx 7 Gbit/s for a single user.

The MIMO technology provides the system with the spatial multiplexing gain and spatial diversity gain.

In spatial multiplexing, multiple antennas are used on the receive end and transmit end and multipath components in spatial communication are used, allowing signals to be transmitted over multiple data channels (MIMO sub-channels) in the same frequency band. This technology makes the channel capacity linearly increase with the growing number of antennas. This increase in channel capacity does not require additional bandwidth and does not consume additional transmit power. Therefore, spatial multiplexing is an efficient means to improve channel capacity and system capacity.

In spatial multiplexing, serial-to-parallel conversion is performed on the transmitted signal to produce several parallel signal flows, which are then transmitted using their respective antennas in the same frequency band simultaneously. Due to the use of multipath propagation, each transmit antenna produces a unique spatial signal for the receive end. After the receive end receives the mixed signals of data, it differentiates these parallel data flows based on the fading between different spatial channels. Spatial multiplexing requires the spacing between transmit and receive antennas to be greater than the distance, ensuring that each sub-channel of the receive end is an independently fading channel.

Benefits :-

  • Improved maximum throughput
  • Increased number of users
  • Enhanced link reliability

Maximal ratio combining (MRC)

The maximal ratio combining (MRC) technology improves the signal quality of the receiving end.

In MRC, the same signal from the transmit end is received by the receive end through multiple paths (multiple antennas) because the receive end receives this signal using multiple antennas. Generally, among multiple paths, there is one path providing better signal quality than the other paths. The receive end uses a certain algorithm to allocate different weights to receiving paths. For example, the receive end allocates the highest weight to the receiving path providing the best signal quality, which improves the signal quality of the receive end. When none of multiple receiving paths can provide better signal quality, the MRC technology can ensure better receive signals.

USB SF Mode

It is related to the USB port of the computer in which the USB WiFi adapter is connected.

USB Switch Mode

It is related to the USB port of the computer in which the USB WiFi adapter is connected.

  • USB Mode 1 – It means USB WiFi adapter connected to  USB version 1 port of the computer
  • USB Mode 2 – It means USB WiFi adapter connected to  USB version 2 port of the computer
  • USB Mode 3 – It means USB WiFi adapter connected to  USB version 3 port of the computer

MIMO and beamforming

Both MIMO and beamforming are multi antenna technologies. However, there is an inherent conflict between the antenna requirements required by each technology to optimize performance.
Beamforming shape the beam direction by using constructive and destructive combinations of the same signal phase shifted from multiple antennas. The desired direction is achieved by changes to each antenna phase. In order for the signals to combine, they must have the same polarity.
The beamforming requirements are completely opposite from good MIMO requirements. In order to increase diversity in MIMO, we want signals from different antennas to have orthogonal polarity.

You can optimize your antenna array for either beamforming performance or MIMO – but not both.

Roaming Aggressiveness/Roaming Sensitivity

This setting lets you define how aggressively your wireless client roams to improve the connection to an access point. 

This is useful when the WiFi adapter is working in multiple WiFi Router environment. The WiFi adapter will check the signal strength from the WiFi router to which it is connected. If the signal strength drops below a certain point then it will scan for other WiFi routers with better signal strength. If a WifI router with better signal strength is found then the WiFi adapter will disconnect from the current WiFi router and connect to another WiFi router.

Default: Balanced setting between not roaming and performance.
Lowest: Your wireless client will not roam. Only significant link quality degradation causes it to roam to another access point.
Highest: Your wireless client continuously tracks the link quality. If any degradation occurs, it tries to find and roam to a better access point.

Wake on magic packet
If enabled, the setting wakes the computer from a sleep state when it receives a Magic Packet from a sending computer. The Magic Packet contains the MAC address of the intended destination computer. Enabling turns on Wake on Magic Packet. Disabling turns off Wake on Magic Packet. It only disables the Magic Packet feature, not Wake on Wireless LAN.

Wake on pattern match
Wakes the computer from a sleep state when an adapter receives a particular wake pattern.

U-APSD support
U-APSD (or WMM-Power Save or WMM-PS) is a Wi-Fi capability that saves power consumption on low periodic latency-sensitive traffic modes, like a VoIP. We have identified interoperability (IOT) issues with certain access points that result in reduced RX throughput.

AP mode Force BW20

Enabling this will force channel width to 20 MHz when the Wifi adapter is used for creating a WiFi hotspot.

Selective suspend

Enabling this allows the computer to suspend the idle wifi adapter.

Multimedia/Gaming Environment

Enabling this will enable QoS which will give preference to media streaming and gaming data in the network.

Channel Mode

It applies to dual-band WiFi adapters.

  • Auto/(2.4G + 5G) : The Wifi adapter will support connection to both 2.4 GHz and 5 GHz band.
  • 2.4G only : The Wifi adapter will support a connection in 2.4 GHz band only.
  • 5G only : The Wifi adapter will support a connection in 5 GHz band only

Prefer 5G

  • Enabled : WiFi adapter will prefer connecting to the WiFI network in  5 GHz band.
  • Disabled : No band preference

802.11n Channel Width for band 2.4 GHz 

Allows the user to set channel width at 2.4 GHz band. 

  • 20 MHz only : Only 20 MHz channel width will be used while connecting to the WiFi network at 2.4 GHz band.
  • Auto : Wifi router decides channel width will be used while connecting to the WIFi network at 2.4 GHz band.

802.11n Channel Width for band 5 GHz 

Allows the user to set channel width at 5 GHz band. 

  • 20 MHz only : Only 20 MHz channel width will be used while connecting to the WiFi network at 5 GHz band.
  • Auto : Wifi router decides channel width will be used while connecting to the WIFi network at 5 GHz band.

802.11n Mode

  • Enable :  Enables connection to 802.11n network
  • Disable :  Disables connection to 802.11n network

ARP offloading for WoWLAN
ARP offload is the network adapter’s ability to respond to an IPv4 ARP request without waking the computer. To enable the feature, both the hardware and the driver must support ARP offload.

Ad Hoc QoS Mode
Quality of Service (QoS) control in ad hoc networks. QoS provides prioritization of traffic from the access point over a wireless network based on traffic classification. WMM* (Wi-Fi Multimedia*) is the QoS certification of the Wi-Fi Alliance* (WFA). When WMM* is enabled, the WiFi adapter uses WMM to support priority tagging and queuing capabilities for Wi-Fi* networks.

Ad Hoc Power Management

Set power saving features for Device to Device (ad hoc) networks.

  • Disable: Select when connecting to ad hoc networks that contain stations that do not support ad hoc power management.
  • Maximum Power Savings: Select to optimize battery life.
  • Noisy Environment: Select to optimize performance or connecting with multiple clients.

Intel Wireless Adapter Settings Descriptions:  https://www.intel.com/content/www/us/en/support/articles/000005585/network-and-i-o/wireless.html


Optional feature in Wifi Adapters

These features are optional to be implemented in the WiFi adapter or Wifi router.

802.11n  –

  • 40 MHz channel bandwidths
  • Two to four spatial streams (antenna)
  • Low-density parity-check code (LDPC)
  • Space-Time Block Coding (STBC)
  • Transmit Beamforming (TxBF)
  • 400 ns short guard interval (SGI)

802.11ac –

  • Two to Eight spatial streams (antenna), Supports up to eight spatial streams (AP); client devices up to four spatial streams
  • Low-density parity-check code (LDPC)
  • Space-Time Block Coding (STBC)
  • Transmit Beamforming (TxBF)
  • 400 ns short guard interval (SGI)
  • 160 MHz channel bandwidths (contiguous 80+80)
  • 80+80 MHz channel bonding (discontiguous 80+80)
  • modulation & coding – MCS 8 (256-QAM, 3/4) and MCS 9 (256-QAM,  5/6)
  • Multi-user-MIMO
  • Guard Interval –  short (400 nsec)

 

WiFi Adapter advanced settings 

The features enabled in WiFi adapter will work only if the WiFi router also supports that feature.

  • Open Control Panel > Device Manger.
  • In Device Manager open Network Adapters > (Wifi Adapter) > Properties.
  • Right-click the wireless adapter and click Properties.
  •  

  • Click the Advanced tab to configure the advanced settings.

Tplink WiFi adpater 802.11n 802.11ac  settings 1

This is default settings –

AdaptivityPara = “0”

BeamCap = “BEAM Disable”

EnableAdaptivity = “Auto”

High Adhoc Mode = “Disable”

HLDiffForAdaptivity = “7”

L2HForAdaptivity = “Auto”

LdpcCap = “VHT LDPC TX|HT LDPC TX “

Preferred Band = “No preference”

QoS Support = “Support QoS”

StbcCap = “VHT STBC TX|RX & HT STBC TX|RX “

USB SF Mode = “Disable”

USB Switch Mode = “Auto”

VHT 2.4G = “Enable”

Wireless Mode = “Auto”

Tplink WiFi adpater 802.11n 802.11ac settings 2

  1. Enabling all the features of WiFi adapter. If both the Wifi router and WiFi adapter support the feature then it will be used.
  2. Beamforming ( BeamCap) feature turned ON. Beamforming could be helpful if  few devices are connected to the WiFi router. For beamforming to work Wifi router needs to have more antenna than the number of antennas in the Wifi adapter. If your 802.11 ac WiFi adapter has 2 antenna beamforming feature would require four or more antenna dedicated to that 5 GHz frequency band to host 802.11ac Wifi Access point.
  3. Turn ON LdpcCap for both VHT and HT  transmit and receive.
  4. This is the setting I recommned to be used by most users.

AdaptivityPara = “0”

BeamCap = “VHT BEAM TX|RX & HT BEAM TX|RX”

EnableAdaptivity = “Auto”

High Adhoc Mode = “Disable”

HLDiffForAdaptivity = “7”

L2HForAdaptivity = “Auto”

LdpcCap = “VHT LDPC TX|RX & HT LDPC TX \rx”

Preferred Band = “No preference”

QoS Support = “Support QoS”

StbcCap = “VHT STBC TX|RX & HT STBC TX|RX “

USB SF Mode = “Disable”

USB Switch Mode = “Auto”

VHT 2.4G = “Disable”

Wireless Mode = “Auto”

Tplink WiFi adpater 802.11n 802.11ac settings 3

For a quick response, it would be better to turn OFF unnecessary feature that requires processing power which can be time-consuming. So Beamforming is disabled. LdpcCap seems unnecessary. StbcCap seems useful feature so turned ON.

Don’t keep the Wifi adapter far from the WIFI router.

AdaptivityPara = “0”

BeamCap = “Disable”

EnableAdaptivity = “Auto”

High Adhoc Mode = “Disable”

HLDiffForAdaptivity = “7”

L2HForAdaptivity = “Auto”

LdpcCap = “Disable “

Preferred Band = “No preference”

QoS Support = “Support QoS”

StbcCap = “VHT STBC TX|RX & HT STBC TX|RX “

USB SF Mode = “Disable”

USB Switch Mode = “Auto”

VHT 2.4G = “Disable”

Wireless Mode = “Auto”

Tplink WiFi adpater 802.11n 802.11ac settings 4

Additionally, if you want to use the only 802.11ac at 5 GHz, then setting Preferred Band and Wireless mode can be useful.

If the WiFi adapter is connected to USB 3 port of the computer then you can set USB Switch Mode = “USB Mode3

I have set USB SF Mode = “Enable” . But I have no ides what it does.

—–

AdaptivityPara = “0”

BeamCap = “Disable”

EnableAdaptivity = “Enable”

High Adhoc Mode = “Disable”

HLDiffForAdaptivity = “7”

L2HForAdaptivity = “Auto”

LdpcCap = “Disable “

Preferred Band = “5G First”

QoS Support = “Support QoS”

StbcCap = “VHT STBC TX|RX & HT STBC TX|RX “

USB SF Mode = “Enable”

USB Switch Mode = “Auto”

VHT 2.4G = “Disable”

Wireless Mode = “IEEE 802.11ac”

—————

TpLink Wireless USB Adapater settings

  • AP Mode Force BW20 : Enable
  • IEEE802.11h : Disable
  • Multimedia/Gaming Environment : Enable
  • Prefer 5G : Enable
  • Roaming Sensitivity : Disable
  • Selective suspend : Disable

Realtek Wireless LAN 802.11n Settings

  • Bandwidth : 20Mhz Only
  • Roaming Sensitivity Level :  Disabled
  • Wireless Mode : Auto

Edimax Wireless USB adapter 802.11n Settings

  • AP Mode Force BW20 : Disable
  • Multimedia/Gaming Environment : Enable
  • Randio On/Off : Enable
  • Roaming Sensitivity : Disable
  • Selective suspend : Disable

  • Channel Width for 2.4 Ghz : 20 Mhz
  • Global BG Scan blocking : Always
  • Preferred band : Prefer 5GHz band
  • Roaming Aggressiveness : lowest
  • Throughput Booster : Disabled
  • Transmit Power : Highest

  • 802.11n Channel Width for band 2.4 GHz : 20MHz only
  • Mixed mode protection : RTS/CTS Enabled
  • Preferred band : Prefer 5.2 GHz
  • Roaming Aggressiveness: lowest

  • AP mode Force BW20 : Enable
  • Channel Mode: 2.4G + 5G
  • Multimedia/Gaming Environment : Enable
  • Prefer 5G : Enable
  • Roaming Sensitivity: Disable
  • Selective suspend : Dsiable

Other Setting you may see in other wifi adapters

  • Channel Width for 2.4 Ghz : 20 Mhz
  • Channel Width for 5GHz : Auto
  • Roaming Aggressiveness/Roaming Sensitivity :  Lowest/Disabled
  • Roaming Tendency : Off
  • Throughput Booster/Throughput Enhancement : Disabled
  • Transmit Power : Highest
  • Preferred band : Prefer 5GHz band, Prefer 5.2 GHz band
  • Fat Channel Intolerant : Disabled
  • VHT 2.4G IOT : Enable
  • WiFi Config : Performance
  • Global BG scan blocking : Always
  • Mixed-mode protection : RTS/CTS Enabled
  • Power Output: 100%
  •  
  1. Tips to increase WiFi speed : https://www.intel.in/content/www/in/en/tech-tips-and-tricks/how-to-increase-wifi-speed.html
  2. Improving wireless range : https://kb.netgear.com/1114/Improving-wireless-range-Overview
  3. Cause of poor signal strength due to obstructions and interference: https://www.linksys.com/ca/support-article?articleNum=141729
  4. Picking best location for antennas : https://kb.netgear.com/1032/Picking-best-location-for-antennas
  5. Common Sources of Wireless Interference : https://documentation.meraki.com/MR/WiFi_Basics_and_Best_Practices/Common_Sources_of_Wireless_Interference
  6. How to improve the speed of TP-Link wireless adapters : https://www.tp-link.com/us/support/faq/709/
  7. Different Wi-Fi Protocols and Data Rates : https://www.intel.com/content/www/us/en/support/articles/000005725/network-and-i-o/wireless.html