CCNA Wireless – CCNA Wireless Notes Chapter 1
I’ve started studying for the CCNA wireless exam and thought I would put my notes online. I always learn better when writing and hopefully my notes can be of assistance to someone else. These notes are based on reading the official certification guide “CCNA Wireless 200-355 Official Cert Guide“.
Basic wireless theory
Wireless LANs are based on the 802.11 standard.
Wireless LANs is a lot about Radio Frequency (RF) and planning of the RF environment.
When alternating current is sent through the antenna electric and magnetic fields propagate out and away as traveling waves. They travel along each other and are at right angles to each other.
Electromagnetic waves do not travel in a straight line. They travel by expanding in all directions away from the antenna.
When the electromagnetic waves reach the receiver’s antenna, they induce an electrical signal.
Frequency
Frequency – The number of times a signal makes one complete up and down cycle in one second. Measured in Hertz (Hz)
The frequency range from 3 kHz to 300 GHz is commonly called RF. Types of devices in this frequency range is radar, radio, shortwave radio, television, FM radio, microwave etc. The main two frequency Continue reading
WiFi’s evolving role in IoT
This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitter’s approach.
Internet of Things applications have diverse connectivity requirements in terms of range, data throughput, energy efficiency and device cost. WiFi is often an obvious choice because in-building WiFi coverage is almost ubiquitous, but it is not always the appropriate choice. This article examines the role WiFi can play and two emerging IEEE standards, 802.11ah and 802.11ax.
Data transfer requirements for IoT vary from small, intermittent payloads like utility meters to large amounts of continuous data such as real-time video surveillance. Range requirements can span from very short distances for wearables to several kilometers for weather and agriculture applications.
To read this article in full or to leave a comment, please click here
WiFi’s evolving role in IoT
This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitter’s approach.
Internet of Things applications have diverse connectivity requirements in terms of range, data throughput, energy efficiency and device cost. WiFi is often an obvious choice because in-building WiFi coverage is almost ubiquitous, but it is not always the appropriate choice. This article examines the role WiFi can play and two emerging IEEE standards, 802.11ah and 802.11ax.
Data transfer requirements for IoT vary from small, intermittent payloads like utility meters to large amounts of continuous data such as real-time video surveillance. Range requirements can span from very short distances for wearables to several kilometers for weather and agriculture applications.
To read this article in full or to leave a comment, please click here
WiFi’s evolving role in IoT
This vendor-written tech primer has been edited by Network World to eliminate product promotion, but readers should note it will likely favor the submitter’s approach.
Internet of Things applications have diverse connectivity requirements in terms of range, data throughput, energy efficiency and device cost. WiFi is often an obvious choice because in-building WiFi coverage is almost ubiquitous, but it is not always the appropriate choice. This article examines the role WiFi can play and two emerging IEEE standards, 802.11ah and 802.11ax.
Data transfer requirements for IoT vary from small, intermittent payloads like utility meters to large amounts of continuous data such as real-time video surveillance. Range requirements can span from very short distances for wearables to several kilometers for weather and agriculture applications.
Standing Up to a Dangerous New Breed of Patent Troll
On March 20th, Cloudflare received our first patent infringement claim: Blackbird Tech LLC v. Cloudflare, Inc. Today we’re filing our Answer to that claim in a federal court in Delaware. We have very strong arguments we will present in the litigation, mostly because the patent asserted against us does not have anything to do with our technology.
The infringement claim is not a close one. The asserted patent, US 6453335 (‘335 patent) was filed in 1998, and describes a system for monitoring an existing data channel and inserting error pages when transmission rates fall below a certain level. Nothing from 1998—including the ’335 patent—comes close to describing our state-of-the-art product that is provisioned via DNS, speeds up internet content delivery, and protects against malicious attackers. Our technology is innovative and different, and Cloudflare’s technology has about 150 patents issued or in process.
We also expect to show that the patent itself is invalid. For example, if the ’335 patent is read broadly enough to cover our system (which shouldn’t happen), it would also cover any system where electronic communications are examined and redacted or modified. But this is not new. Filtering products performing similar functions were around long before Continue reading
Project Jengo: Cloudflare’s Prior Art Search Bounty
Jengo Fett by Brickset (Flickr)
As readers of this blog likely know, especially if you read this post, Cloudflare has been sued by a dangerous new breed of patent troll, Blackbird Technologies, asserting a very old and very vague patent. And we know we are not alone in being frustrated about the way that such patent trolls inhibit the growth of innovative companies. Cloudflare is asking for your help in this effort, and we’re putting our money where our mouth is.
Patent trolls take advantage of a system they assume is tilted in their favor, where they can take vague technology patents issued years ago and apply them as broadly as imaginable to the latest technology. And they do this without the limitations of having to show the original patent holder would have actually exercised the patent, because most of them don’t, at all. Patent trolls think they can sit back and pick off settlements from companies because their lawsuits are a nuisance and the costs of defending those suits are considerable.
Changing this dynamic and leveling the playing field is going to require an entirely new approach. Fighting such strong, though perverse, economic incentives is going Continue reading