5 things you need to know about MU-MIMO

October 3, 2019 at 8:00 AM

 

When you’ve got multiple devices using the same network, multi-user MIMO (MU-MIMO) is the way to go. MU-MIMO enables numerous Wi-Fi devices to receive multiple data streams at the same time. This is exceptionally more efficient than the single-user MIMO used by many routers. Here, we’ll take a look at the top 5 things you need to know about MU-MIMO.

 

1.      One-Way or Two-Way

 

Whether MU-MIMO is one-way or two-way depends on the Wi-Fi standard being used. MU-MIMO utilizes the 80211ac standard, which works solely with downlink wireless connections. Simultaneously sending data to multiple users is something that only wireless routers and APs are able to do. When the individual wireless devices are sending data to that router or AP, they have to take turns or separately use SU-MIMO to send multiple streams when it’s their turn. That said, multiple wireless devices will be able to receive data and be able to utilize simultaneous streams for sending data when 802.11ax Wave 2 comes into play.

 

2.      OFDMA Takes It Up a Notch

 

Orthogonal Frequency-Division Multiple Access (OFDMA) technology is part of 802.11ax and separates the channels into smaller segments so multiple devices can communicate at the same time. This technology compliments the capabilities of MU-MIMO. It organizes how the channels are used by allowing each device their own channel so they can coordinate when to talk more easily. While it is similar to MU-MIMO, OFDMA offers a different set of capabilities as it can be used in high density environments with low throughput or small-packet applications like IoT sensors.

 

3.      802.11ax (aka Wi-Fi 6) = Concurrent MU-MIMO Streams

 

The introduction of 802.11ax into the mix increases the number of users in a MU-MIMO group from four to eight. The ability to have more devices connected at the same time can improve throughput and make connections faster.

 

4.      2.4 GHz & 5 GHz are both Options

 

802.11n and 802.11ac limited MU-MIMO to the 5 GHz bandwidth, but with 802.11ax, MU-MIMO will now be able to use both the 2.4 & 5 GHz bands. While 2.4 GHz can only handle a maximum of three, small, legacy channels at one time, this improvement could allow faster speeds in the often overcrowded 2.4 GHz band.

 

5.      Benefits of Beamforming

 

MU-MIMO takes advantage of another feature of 802.11ac and 802.11ax, beamforming. This keeps signals from dispersing randomly in different directions by pointing it to the intended wireless devices. This, in turn, improves Wi-Fi speeds and ranges by using the signal more proficiently.

 

There you have it, five more reasons why MU-MIMO can be a game changer for your wireless network. To read more about MU-MIMO, check out more of our blog posts.

 

Standards Showdown: 802.11 Standards Side-by-Side

July 20, 2017 at 8:00 AM

 

The IEEE is almost always working on another new amendment to the 802.11 Wi-Fi standard. We now have nearly as many 802.11 standards as there are letters in the alphabet, and keeping them straight can get confusing. Fortunately, we’ve compiled a comprehensive list of all of the 802.11 standards, old and new, for easy reference. 

 

All About MU-MIMO

May 25, 2017 at 8:00 AM

 

Multi-user multiple-input multiple-output (MU-MIMO) is the next evolution of MIMO and is revolutionizing that way Wi-Fi routers operate. MU-MIMO allows routers to simultaneously send data to multiple devices. This is much more efficient than single-user multiple-input multiple-output (SU-MIMO) that many routers utilize. MU-MIMO allows all of your devices to simultaneously send and receive data from the router for multiple devices at the same time.

 

If you’re not excited about MU-MIMO yet, here are 5 reasons why you should be:

 

  1. 1.       MU-MIMO eliminates slow Wi-Fi speeds by making your router a super multi-tasker. Instead of sending little bits of information one at a time to each device, the router can now simultaneously transmit data to multiple wireless devices.

 

  1. 2.       MU-MIMO is great for video streaming and other high-bandwidth uses because it delivers a more dependable, faster Wi-Fi connection, there is a noticeable improvement in these data-demanding tasks.

 

  1. 3.       Not only do Wi-Fi networks get faster with MU-MIMO, they gain greater capacity. This means that home networks can service more Wi-Fi devices and public networks with many users will perform better.

 

  1. 4.       Even non-MIMO devices will experience improved performance. To fully utilize MU-MIMO’s benefits, devices must support the technology. But with MU-MIMO devices working faster, the router is free to communicate with other SU-MIMO devices.

 

  1. 5.       MU-MIMO costs less and is easier to implement than SU-MIMO. MU-MIMO doesn’t require multiple antennas or as much signal processing as SU-MIMO. It also uses a simpler standardized beamforming method that makes it easier for manufacturers to support.

 

As with everything, MU-MIMO does have some downfalls. For optimal performance, both the router and device must support MU-MIMO using 802.11ac on the 5GHz frequency. No more than four devices should be connected at one time, for full, optimal performance, and those devices should be stationary and not roaming. MU-MIMO also only improves the connection in one direction, from router to device, or the downlink, not the other way around. Still, MU-MIMO is slated to be a very impactful technology and potentially revolutionize the world of wireless networking. 

 

Cliffs Notes: Industrial Wireless Network Frequencies

September 8, 2016 at 8:00 AM

 

Today’s industrial wireless networks use multiple frequencies in order to support a variety of applications. In a single industrial setting there may be two, three or more frequencies being used since each offers unique capabilities.

 

If you’re trying to decide which frequency would be best for your industrial wireless application, we’re here to help. We’re going old school with a CliffsNotes-style review to sum it all up for you.

 

Summary

 

There are three ISM wireless frequency bands: 900 MHz, 2.4 GHz and 5 GHz. The most popular frequencies used in industrial networks are the 900 MHz and 2.4 GHz bands. Many industrial facilities have such diversified needs and processes that their wireless network uses multiple frequencies. For example, let’s say there’s an oil refinery using a remote monitoring system, a security system and high speed Wi-Fi in the central control office – this situation may require the use of all three frequency bands.

 

Facilities such as oil refineries, wastewater treatment plants and manufacturing operations may have wireless systems that utilize lower bandwidth communications. Simpler tasks like opening a valve or relaying temperature readings from a tank require less bandwidth. In this instance, the 900 MHz frequency band is often used because it allows for longer distance, more reliable transmissions and better penetration of obstructions. This frequency is ideal when remote monitoring of facilities requires a longer reach.

 

These facilities may also use video security systems which are very common in industrial installations. Most security systems use IP cameras which can be wired with cables or may be connected via wireless links. Wireless IP camera networks require higher bandwidth to send video and/or audio. In this case, 2.4 GHz Wi-Fi networks are the best bet. Using an 802.11g/n network provides security systems the speed they need with transmission rates of up to 300 Mbps.

 

5 GHz is not as commonly used as the 900 MHz and 2.4 GHz frequencies in industrial networks. It has the shortest range but offers very high bandwidth which can be overkill for many industrial communication applications.  Often 5 GHz systems are used as a backhaul link to connect two 2.4 GHz systems.

 

Study Guide

 

Here is a handy chart to give you an overview of the ISM band frequencies and how they are used in industrial wireless networks:

 

No matter which frequency best suits your needs, L-com has all of the products to build your industrial wireless network including antennas, amplifiers, splitters/filters and access points

 

For more information on industrial wireless networks, check out our blog post 5 Things You Need To Know About Industrial Wireless.

 

Comments on this post? Other topics you’d like us to cover? Email us at engineeringhub@l-com.com

 

WiFi Alphabet Soup

December 17, 2015 at 8:00 AM

 

In 1997 the Institute of Electrical and Electronics Engineers (IEEE) released the first 802.11 WiFi standard, 802.11-1997. Since then there have been several follow-on releases that have brought improvements in speed, range and capacity.

 

Here, we give you the A to Z on the 802.11 standards. 

 

Old School WiFi

 

Once widely implemented, especially in business networks, 802.11a supports data rates up to 54 Mbps. It utilizes the 5 GHz frequency band, which has significantly less congestion than other bands and less interference from other devices ensuring better signal integrity and fewer dropped connections. One disadvantage of 802.11a is that its effective overall range is slightly less than that of 802.11b and 802.11g. 802.11a signals are more readily absorbed by walls and other solid objects compared to 802.11b/g.

 

802.11b was released in 1999; the same year 802.11a was released. 802.11b access points, interface cards etc. were less expensive than 802.11a equipment which made it affordable for use in home and small business networks. 802.11b is better at penetrating solid objects such as walls compared to 802.11a but its maximum throughput is only 11 Mbps compared to 802.11a’s 54 Mbps. For outdoor networks 802.11b is not as effective as 802.11a at penetrating trees and leaves as it operates in the 2.4 GHz frequency band. 2.4 GHz signals are absorbed by water found in trees and leaves limiting overall outdoor range.

 

Adopted in 2003 with the promise of higher data rates and reduced cost, 802.11g also operates in the 2.4 GHz frequency band. 802.11g supports a maximum throughput of 54 Mbps and is backward compatible with 802.11b devices/networks. 802.11g experiences the same interference issues as 802.11b as it operates in the crowded 2.4 GHz range. Examples of devices that operate in the 2.4 GHz band include microwave ovens, baby monitors, Bluetooth devices and cordless telephones not to mention a multitude of other 802.11b/g access points.  

 

New School WiFi

 

802.11n, released in 2009, was developed to improve network throughput by utilizing multiple antennas to increase data rates. This standard uses both 2.4 GHz and 5 GHz bands and provides high data throughput of up to 600 Mbps. Additionally 802.11n provides superior indoor and outdoor coverage, essentially doubling the range of its predecessors 802.11b/g.  

 

 

802.11n uses Multiple-input Multiple-output (MIMO) technology which is a technique for sending and receiving more than one wireless signal on the same radio channel at the same time which increases overall throughput (up to 600 Mbps!)

 

The most recently released version of the 802.11 standard is 802.11ac. 802.11ac supports data rates of up to 1.3 Gbps! 802.11ac operates solely in the 5 GHz band, supports MIMO technology and can handle up to four spatial streams (Wave 1) along with wide 80 MHz (Wave 1) channels. 802.11ac also has the advantage of multi-user MIMO or MU-MIMO which is an advanced form of MIMO where an access point can send data to up to four client radios at the same time directing a separate spatial stream to each one compared to 802.11n access points that can only communicate to one client at a time. By implementing MU-MIMO overall WiFi network efficiencies are realized even as more clients are added to the network.

 

Weighing the pros and cons of the different 802.11 standards and being well-versed in the 802.11 vocabulary will help you make an informed decision when planning your next WiFi network.

 

Click on the image below to download our handy 802.11 standards reference chart.

 

 

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