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Enhancing HDX: Introducing Dynamic Bandwidth Selection – Automatically Choosing the “Best” Channel Width

Cisco Systems is announcing a new set of features that enhance its HDX (High Density Experience) suite. This blog is the first in a series that explains the new features that comprise the enhancements to HDX.

Every advancement in Wi-Fi technology comes with corresponding complexities and tradeoffs.  You just don’t get something for nothing.

For example, much of the speed improvements in the evolution from 11b to 11g/a to 11n to 11ac are achieved by simply doubling the RF channel width. Increasing channel width from 20 MHz to 40 MHz effectively enables doubling “over the air” speed. Increasing channel width from 40 MHz to 80 MHz doubles that speed again.

Of course, wider channels are more susceptible to interference (since a wider channel can “hear” more). Furthermore, with wider channels, the number of available so called “non-overlapping” channels decreases making mutual interference an increasing problem. Being able to send data over the air faster is very important, but if the devices in your WLAN are waiting more often to send data because the wider channel is more likely to be busy, then disappointment and unrealized expectations will occur. Keep in mind that because “air is shared” for Wi-Fi that it uses a “listen before talk” protocol.

Also, in a real world WLAN, it is highly unlikely to have homogeneous device types. The client mix will include legacy devices that simply can’t operate at 80 MHz (or 40 MHz). This means that spectrum could be wasted if the network is configured for a greater channel width than most of its devices can handle. This has far more consequences at 5 GHz than at 2.4 GHz since 40 MHz channels are unlikely to be usable at 2.4 GHz and 80 MHz channels cannot be used at 2.4 GHz.

Interestingly, 802.11ac does include a feature called RTS/CTS with bandwidth indication that is intended to address dynamic channel width (read more about this in 802.11ac: The Fifth Generation of Wi-Fi” section 2.3.4). The challenge is that this feature is not often used and cannot be used by either 11a or 11n clients.

Last, but far from least, no two wireless networks are the same – every wireless network is different. Even parts of the same wireless network will be different. Thus, there really is no “one size fits all” static configuration that helps offer optimization. The Wi-Fi network needs to adapt as conditions change. Read More »

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The shift in Education towards Mobile Learning

Technology is important to children in terms of how they learn and how they live. A challenge for many school districts is the ability to offer a mobile learning by putting digital resources in a student’s hands with constrained funding for education.

mobile learning

Katy Independent School District located in Katy TX needed a wireless infrastructure that would support this vision. With over 62,000 students, Katy ISD needed to move from a wireless network that was built for coverage to a network that is built for density. By providing 802.11ac-based Wi-Fi access points in classrooms and outdoor locations and centralized management, the school district is supporting more than 40,000 concurrent Wi-Fi users and empowering faculty, students and staff. Read More »

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Fundamentals of 802.11ac Wave 2

Fundamentals of 802.11ac Wave 2 from TechWiseTV

Fundamentals of 802.11ac Wave 2 from TechWiseTV

How well do you understand this Wave 2 release of the 802.11ac specification?  Our latest ‘Fundamentals of’ addresses the technical differentiators and the potential pitfalls you should be aware of.  There is a lot of power in this wave.

Just 5 Minutes to increase your knowledge: WATCH NOW

I put the full script at the bottom of this blog if interested.

Read more:

Watch some of the earlier wireless fundamentals for even more wireless innovation and (IMHO) great background:

Read More »

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Non-stop wireless at Valley Children’s Hospital

Valley Children’s Hospital is a nonprofit, state-of-the-art, children’s hospital on a 50-acre campus in Madera, California, with a medical staff of more than 550 physicians. With 356 licensed beds, Valley Children’s Hospital is one of the largest hospitals of its type in the nation. One of the core values the hospital embraces is incorporating new ideas, technology and methods to improve the care and services it provides.

Internet of Everything has led to an explosion of wireless devices in the hospital from patient care to guest access. The following blog highlights how the IT Support and Technical Services staff enable the following business outcomes using best-in-class, highly available wireless technology from Cisco:

  • Deliver Emergency Health Records to emergency staff on hundreds of virtual desktops and tablets from the patient’s bedside.
  • Keep nurses connected to patients, doctors and staff via Cisco IP Phones and
  • Provide free internet access to patients, family members and friends



Location: Main campus Madera, California, with several remote sites from Modesto to Bakersfield Read More »

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#CiscoChampion Radio S2|Ep 12. 802.11ac Wave 2

CiscoChampion2015200PX#CiscoChampion Radio is a podcast series by Cisco Champions as technologists. Today we’ll be talking about 802.11ac Wave 2 with Cisco Product Marketing Engineer Mark Denny and Cisco Product Marketing Manager Allen Huotari.

Listen to the Podcast.

Learn about the Cisco Champions Program HERE.
See a list of all #CiscoChampion Radio podcasts HERE.

Cisco SMEs
Mark Denny, Cisco Product Marketing Engineer
Allen Huotari, Cisco Product Marketing Manager

Cisco Champion Guest Hosts
Stewart Goumans, @WirelessStew, Mobility Consultant
Sam Clements, @samuel_clements, Mobility Practice Manager

Lauren Friedman (@Lauren)

What is 802.11ac Wave 2 and why it is important?
Multi-user MIMO
Wave 2 and backwards compatibility
Troubleshooting Wireless Networks and Wave 2
Infrastructure and Power Requirements with Wave 2
AC toolbox recommendations
Wave 2 and disabling NCS rates

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