Popular literature on 802.11ac describes 40 MHz and 80 MHz operation (channel bonding) as doubling and quadrupling of the data rate, respectively. Every time I saw that mentioned, the following question came to my mind.
When radio transmits over 40 MHz (or 80 MHz) channel, is the total transmit power proportionally increased over 20 MHz to maintain the SNR (signal to noise ratio)? And, how is the data rate multiple with channel boding distributed over the cell?
This question nagged me like a little stone in the shoe that is impossible to ignore. My subsequent findings from the lab tests show that the popular literature is only partially true. Read on to find out why. Read more…
802.11ac, WLAN planning
Last week, AirTight’s Senior Technical Marketing Engineer, Robert Ferruolo (@RAFerruolo), added another chapter to the AirTight 802.11ac webinar series. Robert presented on “802.11ac Deeper Dive” focusing on features that come along with the 802.11ac wireless platform.
During the presentation, Robert broke down channel availability, QAM, beamforming, MIMO, MU-MIMO, frame aggregation, and error correction. To view the recording, click here.
Throughout this 6-part series, we’ll continue to break down why 802.11ac should be a serious consideration for your wireless network. The series will address the inevitable migration from 802.11n to 802.11ac.
We’ll be continuing to post our Q&A sessions for all of our webinar series. Stay tuned for more updates on upcoming webinars and their corresponding Q&A sessions.
Last week AirTight launched its 802.11ac webinar series. Throughout this six-part series, we will be touching on various aspects of the 802.11ac wireless platform. The first session touched on the Essentials of 802.11ac.
Upcoming Webinars: 802.11ac Deep Dive & Beyond
We will be continuing the series next week with “802.11ac Deeper Dive.” Stay tuned for later installments in our 802.11ac series, where we’ll be discussing:
- “Is 802.11ac Right for Your Network?”
- “802.11ac Deployment Best Practices”
- “802.11ac Channel Capacity Planning”
- “802.11ac Network Optimization”
Join us for a 45-min webinar on 802.11ac essentials on June 10 (11 am EST or 7 pm EST) with our senior technical marketing engineer, Robert Ferruolo.
- What’s new in 802.11ac standard?
- 802.11ac capabilities compared to 802.11n
- Should I jump in now or wait for 802.11ac Wave 2?
- 802.11ac scalability compared to 802.11n
- How does 802.11ac change the game for client devices?
Edit: We will update the blog with the recording and the presentation.
Meanwhile, you can register for the next webinar in the 802.11ac series to take place on June 24.
There is large and ever increasing assortment of enterprise access points offered by wireless vendors today. APs have different number of radios, number of streams, 11n/11ac, POE compatibility, peripherals, price, etc. While this diversity is overwhelming, have you wondered what lies in the hardware guts of these APs? What are the hardware design concepts that are responsible for rendering feature personality to the AP? How does the hardware ecosystem work among chip vendors, ODMs and AP vendors? What are state of the art hardware architectures for the 802.11ac APs? This blog post discusses key hardware concepts, such as SoC, dedicated CPU and offload architectures that are commonly found inside the APs, along with the ODM sourcing model for the Wi-Fi APs and its implications for product offerings.
Read about trends in education technology: Wi-Fi as a subscription service, outlook for 802.11ac adoption in schools and integration of social media into wireless networking.
BETT 2014, UK’s learning technology show, has been and gone, but it certainly won’t be forgotten! For those in the educational technology sector, be it primary school teachers all the way to network managers of colleges and large secondary schools, this was THE event and is memorable for new technology and aching feet from over 4 days of the conference.
Wireless as as Service for Education
So what was all the fuss about and why was #BETT2014 trending on the social feeds? There were a few noticeable trends this year noted by attendees and exhibitors alike. Firstly came “XXX as a service”! As educational funding changes, so does the need to adapt and service the new legislation whilst still enabling the educational IT needs in what is a constantly evolving technology landscape.
Cloud Wi-Fi as a service
This year’s show was huge. According to the events organizers, there were 1,200 exhibitors and 38,000 healthcare professionals in attendance and there were more nurses, physicians, IT staff and executives in attendance at this year’s HIMSS than ever before.
New Wi-Fi enabled devices and applications at HIMSS14
Wi-Fi helps disabled people walk
One of the most interesting Wi-Fi capable devices at this year’s HIMSS was a Wi-Fi enabled bionic exoskeleton. The Ekso Bionics unit (pictured above) was featured in the Lockheed Martin booth. This device is for patients with lower extremity paralysis or weakness. It enables patients to stand, walk and it can assist them with their rehabilitation. The unit is equipped with a single Wi-Fi radio. The radio supports two data streams currently. One stream allows engineers to see real-time telemetry data to determine how the unit is performing. The other stream is for the unit’s user, where information such as steps taken, distance traveled, etc., are sent over the air to an application that the user can access later.
802.11ac has brought with it MIMO alphabet soup … spatial streams, space-time streams, explicit beam forming, CSD, MU-MIMO. Alphabet soup triggers questions to which curious mind seeks answers. This post is an attempt to explore some questions surrounding explicit beam forming (E-BF) that is available in Wave-1 of 802.11ac. E-BF is a mechanism to manipulate transmissions on multiple antennas to facilitate SNR boosting at the target client.
How is E-BF related to spatial streams?
E-BF is a technique different from spatial streams. E-BF can be used whenever there are multiple antennas on the transmitter, irrespective of the number of spatial streams used for transmission.
In earlier blog posts on 802.11ac practical considerations, we reviewed 80 MHz channels, 256 QAM and 5 GHz migration. Continuing the 802.11ac insights series, in this post we will look at some practical aspects of MU-MIMO, which is the star attraction of the impending Wave-2 of 802.11ac.
MU-MIMO mechanics and 802.11ac standard
Illustration of 802.11ac MU-MIMO
At a high level, MU-MIMO allows AP with multiple antennas to concurrently transmit frames to multiple clients, when each of the multiple clients has lesser antennas than AP. For example, AP with 4 antennas can use 2-stream transmission to a client which has 2 antennas and 1-stream transmission to a client which has 1 antenna, simultaneously. Implicit requirement to attain such concurrent transmission is beamforming, which has to ensure that bits of the first client coherently combine at its location, while bits of the second client do the same at the second client location. It is also important to ensure that bits of the first client form null beam at the location of the second client and vice versa.
Are you considering new Wi-Fi deployment or upgrade of legacy system? Then you should be prepared to navigate the maze of multiple decision factors given that Wi-Fi bake-offs increasingly require multi-faceted evaluation.
Follow these 11 “C”ommandments to navigate the Wi-Fi decision tree:
11aC, and last but not least …
802.11ac, Best practices, WLAN planning