WiFi 802.11ac: What You Need To Know

Recently 802.11ac WiFi devices have started to emerge, but just what is WiFi 802.11ac and How fast is it? 802.11ac is a supercharged version of 802.11n, which is the current WiFi standard, offering link speeds ranging from 433 megabits-per-second (Mbps), through to multiple gigabits per second. To achieve these speeds which are dozens of times faster than 802.11n, 802.11ac works exclusively in the 5GHz band, uses a huge amount of bandwidth (80 or 160MHz) and operates in up to eight spatial streams (MIMO) and a utilizes technology called beamforming.

How 802.11ac works: At its core, 802.11ac is essentially an updated version of 802.11n, which itself introduced some very exciting technologies that brought massive speed boosts over 802.11a and g. Whereas 802.11n had support for four spatial streams (4×4 MIMO) and a channel width of 40MHz, 802.11ac can use eight spatial streams and has channels up to 80MHz wide, which can be combined to make 160MHz channels. Even if everything else remained the same, this means that 802.11n has 8x160MHz of spectral bandwidth to play with, vs. 4x40MHz, this is a huge difference that allows 802.11n to squeeze vast amounts of data across the spectrum.

802.11ac introduces 256-QAM modulation (an increase from 64-QAM in 802.11n), which fits 256 different signals over the same frequency by shifting each signal to a slightly different phase. In theory, this quadruples the spectral efficiency of 802.11ac over 802.11n. Spectral efficiency is a measure of how well a given wireless protocol/modulation/multiplexing technique uses the bandwidth available to it. In the 5GHz band, where channels are fairly wide (20MHz+), spectral efficiency is not so important; in the cellular or mobile bands though, channels are often 5MHz wide, which makes spectral efficiency very important.

802.11ac also introduces standardised beamforming (802.11n was non-standardized, which made interoperability an issue). Beamforming is essentially transmitting radio signals in such a way that they are directed at a specific device. This can increase throughput and also reduce power consumption. Beamforming can be done with smart antennae that physically move to track the device, or by modulating the amplitude and phase of the signals so that they destructively interfere with each other, leaving just a narrow, not-interfered beam. 802.11n uses this second method, which can be implemented by both routers and mobile devices.  Finally, 802.11ac is fully backwards compatible with 802.11n and 802.11g, this means you can buy an 802.11ac router today and it will work with your older WiFi devices.

Just how fast is WiFi 802.11ac?  Well there are two answers: the theoretical max speed that can be achieved in the laboratory, and the practical max speed that we will receive at home or in the office, surrounded by lots of signal altering obstacles.  The theoretical max speed of 802.11ac is eight 160MHz 256-QAM channels, each of which are capable of 866.7Mbps — a total of 6,933Mbps, this is slightly short of 7Gbps. That’s a transfer rate of 900 megabytes per second! which is more than you can squeeze down a SATA 3 link. In the real world, due to channel contention, you probably won’t get more than two or three 160MHz channels, so the max speed comes down to somewhere between 1.7Gbps and 2.5Gbps. Compare this with 802.11n’s max theoretical speed, which was 600Mbps.

Source: http://www.extremetech.com/computing/160837-what-is-802-11ac-and-how-much-faster-than-802-11n-is-it

Google Releases OEM Patch For Major Android Security Flaw

In a follow up to our recent report regarding how an Android Security Bug was found to let hackers gain system access, Google has released a fix to its Android original equipment manufacturers (OEM’s) for this bug, named: Android security bug 8219321 as unearthed by Bluebox Security in February this year. The flaw was confirmed from Google’s Android Communications Manager, Gina Scigliano, she said “a patch has been provided to our partners.” She also mentioned “Some OEMs, like Samsung, are already shipping the fix to the Android devices.”

The flaw in question will allow a hacker to turn a legitimate app into malicious files by modifying APK code without breaking the app’s cryptographic signature. In response to this, Google has already modified its Play Store’s app entry process to scan for the exploit so apps that have been modified using this vulnerability can no longer be distributed via the Play Store. Bluebox Security discovered the hole in Android’s code, which it claims could potentially affect 99 percent of Android devices, back in February and informed Google at that time. (but only made it public recently). Samsung’s Galaxy S4 was named then as one Android device that had already been patched, so it seems likely that this model is the device Gina Scigliano referred to when she cited Samsung as a manufacturer already shipping a fix. The problem for Android users is that even though Google has now in fact released a fix to its OEMs, they still have to wait for the maker of their particular handset to implement and ship the fix. This also poses another question, how long before their particular carrier tests it? Having to wait around to receive updates is a byproduct of the freeness and fragmentation of the Android sphere, still, it does not sound like this particular Android flaw has been widely exploited thus far. Scigliano has told ZDNet: “We have not seen any evidence of exploitation in Google Play or other app stores via our security scanning tools. Google Play scans for this issue and Verify Apps provides protection for Android users who download apps to their devices outside of Play.” But just because it has not been widely exploited yet, does not mean it will not be…does it?

Source: http://techcrunch.com/2013/07/09/google-plugs-android-hole/

How To Remove/Disable Facebook Timeline Profile?

If you don’t like the new Timeline feature on Facebook and want to view profiles in the old style, then TimelineRemove is the perfect browser extension for you. (Firefox, Internet Explorer, Chrome and Safari) included in one zip!

This tiny, but handy tool disables the new Facebook timeline feature and restores the classic look, without changing the timeline behavior for other visitors of your Facebook profile. The extension basically works by hiding the timeline, so you can view your own and others’ profiles in the old style.

TimelineRemove works automatically once installed, and a button is added to the toolbar that lets you toggle the timeline on and off, whenever you want.

Editor's Note: The download contains 3 files; .xpi for Firefox, .exe for Internet Explorer, .safariextz for Safari and .crx for Chrome.
- Download -

You can visit the author link to download individually.

How To Claim Token in Technorati

Perhaps, until now there are still some people who ask. How to claim your blog in Technorati?

This is my token: 23CU2ED5MGM2

Technorati as the site contains a directory of blog is a website directory of the most popular blogs by the bloggers in the world. In addition, Technorati is also very influential on the blog visitor traffic.

So, how do I claim?

Well, if you have not registered please register HERE. If already registered please go to HERE. Then, go to your profile and start claiming your blog. Fill in the blog data in the form recommended. Once you have click "Start claim" and check your e-mail, e-mail there from Technorati's "Technorati Claim in progress" that contain tokens like this 23CU2ED5MGM2. After that make a post on your blog and insert the token into your blog post. For example as I am, but you can also just simply insert the token into a new post. Because Technorati verify the token via the "RSS Feed" blog that had been loaded on the form. THIS WAY to check please. Scroll down and click "Check Claim". Wait till you get e-mails from Technorati, at least 24-72 hours. Completed.

Hopefully this article can help you. =)

Some Of The Tools To Fight Against SOPA and PIPA

The Stop Online Piracy Act (SOPA) and the Protect IP Act (PIPA) are two bills that sound like they have a mildly positive aim but, in reality, have serious potential to negatively change the internet as we know it. Here are some tools that can help you keep track of SOPA and PIPA as well as prepare for problems in case they pass.

Protect Yourself in Advance

Google Chrome users can pick up the No SOPA, which reveals which sites support SOPA when visiting them. If you're interested in writing a letter to supporters, boycotting their sites, or simply be aware of their support, this extension can help with identification.

Google Chrome users should check out MAFIAAFire Redirector, which will intercept any domain names typed into your address bar and load via the site's numeric IP address instead. Firefox users have the choice of two extensions, DeSOPA and MAFIAAFire ThePirateBay Dancing, which do the same thing.

Additionally, Reddit users are creating a SOPA emergency list that hold the IP addresses of various sites. In the event these extensions don't work out or there isn't one for your browser, you'll be able to make edits to the hosts file on your computer to override any blocked sites. For now there's no sense in doing anything because there is no problem yet, but it's good to be prepared for the worst.

SOURCE: Lifehacker

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