BRKEWN-2017 – Understanding RF Fundamentals and the Radio Design of 11n/ac Networks


Presenter: Fred Niehaus, Technical Marketing Engineer, Cisco Wireless Networking Group

Basic understanding of radio:

  • Every radio wave has a physical size (proportionate to its wavelength)
  • The lower the frequency, the physically longer the radio wave
  • Higher frequencies have shorter waves and as such, takes more power to move them greater distances
  • 5Ghz UNI 2 and UNI 2 Ext overlap with DFS (RADAR)
  • Dynamic Freq Selection (DFS) requires that if a radio is operating in UNI 2/UNI 2 Ext and it hears something that is not WiFi, it has to get off that channel

Antenna basics:

  • Directional or omnidirectional (360 degree)
  • Cisco color markings: blue: 5, black 2.4, orange 2.4 and 5ghz
  • Low gain omnidirectional antennas radiate in a beach ball pattern
  • Omni-direction dipoles in a pancake pattern
  • Yagis are directional; radiate more like a flashlight
  • Patch: multiple elements in a square form factor; radiates like a flashlight
  • Dipole: does not require a ground plane as the bottom half is the ground
  • Monopole requires a (conductive surface) ground plate; monopoles are shorter than dipoles and often used on APs (because of the smaller size) and they can use the metal in the AP as the ground plate.
  • Azimuth: how Continue reading

iPhone 7 to have nearly 15% bigger battery than the iPhone 6s

Noted iPhone leaker OnLeaks (aka Steve Hemmerstoffer of Nowhereelse.fr) published an interesting tweet earlier today indicating that the iPhone 7 may finally address one of the more longstanding complaints about Apple's iconic smartphone: battery life. To be clear, Apple has made tremendous improvements in the iPhone's battery technology over the years, but as we continue to demand more and more from our smartphones, many people find that they can't even go a full day on their iPhone with a single charge.That being the case, OnLeaks's tweet relays that the iPhone 7's battery will have nearly 15% more capacity than the iPhone 6s battery. Pretty reliable (not 100% but almost...) source told me #iPhone7 battery = 1960mAh (#iPhone6s = 1715mAh)To read this article in full or to leave a comment, please click here

UNH SDN consortium promises interoperability testing, benchmarking

Looking to help business customers ensure their Software Defined Networking products and applications work and perform properly, the University of New Hampshire InterOperability Laboratory (UNH-IOL) this week said it would form consortium to perform controller and switch interoperability, conformance and benchmark testing. The Software-Defined Networking (SDN) Consortium expects to open for business August 1 and the 28,000 square foot lab will be working with Spirent Communications and Ixia to develop performance tests said Timothy Winters, UNH-IOL Senior Executive, Software and IP Networking.To read this article in full or to leave a comment, please click here

UNH SDN consortium promises interoperability testing, benchmarking

Looking to help business customers ensure their Software Defined Networking products and applications work and perform properly, the University of New Hampshire InterOperability Laboratory (UNH-IOL) this week said it would form consortium to perform controller and switch interoperability, conformance and benchmark testing. The Software-Defined Networking (SDN) Consortium expects to open for business August 1 and the 28,000 square foot lab will be working with Spirent Communications and Ixia to develop performance tests said Timothy Winters, UNH-IOL Senior Executive, Software and IP Networking.To read this article in full or to leave a comment, please click here

Microsoft customizes Surface tablets for enterprises

Microsoft is doing new things with its Surface tablets, and hoping that enterprises will find a lot to like.The company is taking steps to tailor the tablets to the needs of enterprises. The goal of customization is to differentiate the Surface from look-alike products, and to tie devices closely to a company's operations."We're going to meet the enterprise on their terms," said Hayete Gallot, general manager of Microsoft Devices, in an interview with the IDG News Service.Surface tablets have been successful with consumers and professionals, and Microsoft is giving it an additional enterprise twist. The effort comes as companies look to upgrade to Windows 10 PCs, with tablet-laptop hybrids like Surface being popular replacements.To read this article in full or to leave a comment, please click here

Microsoft reveals details of Windows 10 subscription model

It was always Microsoft's intention to turn Windows 10 into a cloud service with a monthly subscription attached, and now the company has rolled out details of its new subscriptions for enterprise customers, which will be introduced later this year. Microsoft made the announcement at the Worldwide Partner Conference currently taking place in Toronto. Starting this fall, the company will offer Windows 10 Enterprise E3 through its Cloud Solution Provider (CSP) network on a subscription basis at $7 per seat.To read this article in full or to leave a comment, please click here

New York driver crashes car into tree while playing Pokémon Go

A driver in New York state ran his car off the road and into a tree last night as a result of playing "Pokémon Go."Police in Auburn, a town near Syracuse in upstate New York, were called to a traffic accident shortly before 11 p.m."The driver admitted to actively playing the Pokémon Go game while driving causing him to become distracted and run off the roadway into a tree," the police said in a statement.The car was badly damaged in the accident and police say the driver is lucky he was not seriously injured."This is an example of how easily accidents can occur when someone is engaged in the game and not paying attention," the police said.To read this article in full or to leave a comment, please click here

The Ansible At Red Hat Summit Recap

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Red Hat Summit 2016 was the largest gathering of customers, partners and open source contributors yet with Ansible users and executives contributing in various sessions throughout Summit. These sessions covered topics on DevOps, Automation, Management, Best Practices and more. 

Did you miss us at Summit in San Francisco? Well good news, we've compiled a list of all Ansible related sessions below. Also, AnsibleFest 2016 in San Francisco is also right around the corner on July 28th. But if you want to start digging deeper into Ansible now, see below:

 

DevOps Lessons Automating the Deployment of J.Crew's Website with Ansible (PDF)

Oscar Gonzalez

 

Ansible Best Practices For Startups to Enterprises (PDF)

Tim Appnel and James Martin

 

Red Hat Satellite and Ansible Tower by Red Hat: Doing More Together (Video)

Justin Nemmers and Chris Wells

 

When Flexibility Met Simplicity: The Friendship of OpenStack and Ansible (PDF)

Robyn Bergeron and Major Hayden

 

Reduce Complexity and Increase Optimization with Ansible Automation (PDF)

Jon Davila

 

Ansible Accelerates Deployment at Société Générale (Blog)

Fabrice Bernhard and Justin Nemmers

 

Using Ansible to Install Containers On Red Hat Enterprise Linux Atomic Host (Blog)

Matt Micene and Greg DeKoenigsberg

 

Ansible Essentials: Deploy Apps, Manage Systems, and Securely Continue reading

Slideshow: Inside Facebook’s lab where it tests 2,000 phones at once

Facebook can test its code on 2,000 phones at onceImage by FacebookFacebook makes thousands of changes in its code every week. Any one of them could accidentally cause Facebook software to take up more data, memory or battery life on your phone. So the company tests code on more than 2,000 phones to account for different hardware models, operating systems and network connections.To read this article in full or to leave a comment, please click here

Microsoft spices up Surface Hub with Azure cloud services

Microsoft's supersize Surface Hub is often viewed as a computer for videoconferencing and digital whiteboarding, but it is emerging as more than just the centerpiece of a conference room.The Surface Hub is a one-of-a-kind, all-in-one PC with a 55- or 84-inch screen that started shipping a few months back. The device provides new ways for users to present, exchange, share and manipulate data from the Azure cloud, said Hayete Gallot, general manager at Microsoft Devices.Users are still exploring ways in which it can be used. The large screen and collaborative features can be powerful tools in visualizing data extracted from the cloud, Gallot suggests.To read this article in full or to leave a comment, please click here

Worth Reading: Who’s world is this?

On both sides of the Atlantic, we are witnessing the dramatic expansion of government hacking powers. In the United States, a proposed amendment to Rule 41 of the Federal Rules of Criminal Procedure would permit the government to obtain a warrant, in certain circumstances, to hack unspecified numbers of electronic devices anywhere in the world. Meanwhile, across the pond, the British Parliament is currently debating the Investigatory Powers Bill, which (among many other things) would authorize the government to hack the devices of broad classes of people without geographic limitation. The exercise of these powers will have significant implications for the privacy and security of individuals around the world and therefore commands our attention. —Just Security

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The post Worth Reading: Who’s world is this? appeared first on 'net work.

Save Hundreds On The Complete Linux System Administrator Bundle – Deal Alert

You don’t need a fancy college degree (and $100,000 in student debt) to land a tech job, as long as you can prove you’ve got the skills. And because Linux is such an in-demand skill, underlying everything from desktop performance to online security--it’s a great place to start. The Complete Linux System Administrator Bundle will more than get you up to speed, and it’s now only $69.Packed with over 100 hours of instruction, this bundle will help you dive into Linux, the popular open-source operating system. Throughout its 7 courses, you’ll make your way from Linux/Unix basics to more advanced concepts like penetration testing, bash scripting, and openSUSE system administration. With such a robust curriculum, this bundle has everything you need to become a Linux pro.To read this article in full or to leave a comment, please click here

Microsoft touts $404 per user savings with Windows 10

Microsoft this week said enterprises and organizations could save up to $404 per employee over a three-year span by adopting Windows 10.That claim came from a company-commissioned analysis done by Forrester Research. After interviewing four Microsoft customers which have begun migrations from Windows 7 to Windows 10, Forrester created a hypothetical composite organization -- one with 24,000 Windows devices, and a large number of mobile workers among its 20,000 employees -- that it then used to model costs of rolling out Windows 10 and savings generated after the fact.To read this article in full or to leave a comment, please click here

26% off Miracle-Gro AeroGarden Bounty with Gourmet Herb Seed Pod Kit – Deal Alert

The Miracle-Grow AeroGarden, with room for 9 plants and 45 Watts of LED Lighting, the AeroGarden Bounty is the largest and most powerful AeroGarden to date. It comes with a Gourmet Herbs Seed Kit that will deliver fresh, flavorful herbs right at your fingertips. The easy-to-use Control Panel has an interactive LCD display that utilizes on screen prompts to guide you from set up to harvest. It automatically creates optimal conditions for your plants by turning the lights on and off and reminding you when to add water and our Specially Formulated Liquid Plant Food.To read this article in full or to leave a comment, please click here

IDG Contributor Network: Samsung’s new UFS memory cards as fast as SSD drives

External storage cards that read more than five-times faster than normal microSD cards are being released by Samsung, the company announced.The cards, using the Universal Flash Storage (UFS) standard read at 530 megabytes per second. That read speed is comparable to SATA Solid State Drives or Disks (SSDs).Write speeds are about double the fastest microSD cards, with sequential write speeds of 170 megabytes per second, Samsung claims in a press release.To read this article in full or to leave a comment, please click here

Google Glass takes flight at Boeing

Boeing, the largest aerospace company on the planet, builds a lot of planes. The organization manufactures aircraft for airlines and governments in more than 150 countries. And every one of those planes contains thousands of wires that connect its various electrical systems.These complex webs of wires don't weave themselves, and putting all the parts together is a monumental task. Each week, thousands of Boeing's U.S. workers construct "wire harnesses," or "people-size portions of the electrical systems" designed to help them join the various shapes and sizes of wires, according to Kyle Tsai, a research and development (R&D) engineer with Boeing Research and Technology (BRT), the company's central R&D organization. "Wire harnesses are very complex and very dense, and the technicians have to use what are, in essence, roadmaps to find the attachment points and connector pins," Tsai says. "There are so many that it can be information overload at times."To read this article in full or to leave a comment, please click here

MPI and Scalable Distributed Machine Learning

MPI (Message Passing Interface) is the de facto standard distributed communications framework for scientific and commercial parallel distributed computing. The Intel MPI implementation is a core technology in the Intel Scalable System Framework that provides programmers a “drop-in” MPICH replacement library that can deliver the performance benefits of the Intel Omni-Path Architecture (Intel OPA ) communications fabric plus high core count Intel Xeon and Intel Xeon Phi processors.

“Drop-in” literally means that programmers can set an environmental variable to dynamically load the highly tuned and optimized Intel MPI library – no recompilation required! Of course, Intel’s MPI library supports other …

MPI and Scalable Distributed Machine Learning was written by Nicole Hemsoth at The Next Platform.

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