Sirenas:Mito o realidad (video completo del programa Discovery channel 2012)

Fundamentals of Spatial Streams

IEEE 802.11ac: Learn the Fundamentals of the New WLAN Standard

The IEEE 802.11ac Wi-Fi standard promises to deliver greater than a Gigabit connectivity for the next generation of mobile devices. Learn more: http://www.merunetworks.com/products/...

What is 802.11ac? 

Avril Salter, Wireless Deployment Specialist, Next Direction Technologies

AC is a new radio. We've had B, A, G, N, and we've now got AC. Why it's really exciting is it's going to go up to much, much higher data rates. It's also going to allow you to have much higher capacity of wireless traffic across your network.

How does it do that? It has several key features. One of the main features is it goes to wider bandwidths. In N, we've go 20 and 40 megahertz, and now we're going to 80 and also an option to go to 160 megahertz, significantly increasing your data rate. 

It's also introducing spatial multiplexing up to an 8x8 MIMO. There are 8 antennas, which is pretty amazing if you think about using 8 antennas on this equipment now.

The very first products you're going to see 2013 in the enterprise environment we anticipate will be a 3x3 MIMO. What that one may be able to do is get up to data rates which is over a gigabit per second. We're looking at 1.3 Gbps in good RF conditions. So it's going to give you a much, much richer user environment for doing data, video, etc. 

There are also some really other interesting features. One of the things that's also going to incrementally increase your data rate is going to 256 QAM, a much, much higher level of modulation, which I have never seen except in microwave links before. So we're now seen that in a Wi-Fi environment, and what's nice with that one is we're going to couple that with beamforming, so focusing your energy in one direction, which will allow you to get up to those higher data rates much further away from your access point, which is just really exciting that you can get now higher data rates by using these more advanced technologies.

The other one which we've not seen before is called multi-user MIMO and multi-user MIMO is actually going to allow you to have up to four users transmitting at the same time. Historically, we've had one use of our access point, and now we have four. That's going to be up to fourfold in your capacity. 

Not only are you going to have higher data rates, but you're going to have higher capacity as well. So this is super exciting that we have this new radio coming out.

Fly airplane

Block Websites from your Router or using DNS

September 20th, 2012 by Aseem Kishore | File in: Featured Posts, How-To

Looking for a way to block websites in your home so that anyone connected to your network cannot access them? There are lots of programs out there that you can install on a PC or Mac to block or filter websites, but I don’t like these solutions because you have to manually install it on each computer and for any new devices that get connected to the network, they won’t be blocked.

On top of that, what if you want to block the site on other devices connected to wifi like tablets or smartphones? Well, instead of blocking websites on a device by device basis, you can block websites from your wireless router! This is great because all traffic on your internal network has to pass through your router. If you block it here, there is no need to install any software on any computer or to make any changes to the settings on any computer.

This means you don’t have to bother with proxy servers, group policy or secret software running on machines in order to block a few websites. In this article, I’ll show you how you can use your router or use DNS to block websites. All the action takes place on your router.

Block Websites on Router

Just about every router today now has the option to block or filter websites right on the router. For example, I have a Netgear N600 wireless router and there is a whole section called Content Filtering. You’ll need to log into the web interface of your router in order to access these settings.

If you click on Block Sites, you can block on a schedule or block all the time. So you could set it up so that the sites are only blocked at night or during the hours you choose. So you can prevent your kids from browsing Facebook after 9 pm very easily. Just type in the domain name or a keyword if you block websites with certain words in the URL.

It even has the option to allow trusted IP addresses to access the blocked sites, so you can give your computer a static IP address and add it to the list. This way, you can browse everything, but no one else will be able too. In addition to blocking websites, Netgear also has options for blocking services, so you can block all FTP traffic or all AIM traffic. You can create alerts and get emails when someone tries to visit a blocked website.

Not all routers will have the same number of features like Netgear, but there is usually at least a minimum ability to block websites. If your router simply doesn’t have any mechanism for blocking sites via the software, then you can try using DNS.

Block Websites using DNS

On your router, you can also block websites by using another DNS service provider other than your ISP. OpenDNS is an awesome DNS service provider that gives you free content filtering for home use. All you have to do is sign up for a free account and change the DNS servers on your router to point to the OpenDNS servers.

OpenDNS even has a section on how to change the DNS settings for just about every router out there. You can check out this link to change yours:

https://store.opendns.com/setup/router/

Note that you should sign up for a free Home account, not a Premium DNS account. The Home account is what gives you the ability to block individual websites. It’s great that the service is free and OpenDNS may actually be faster than your ISP DNS servers.

Those are two excellent ways of blocking websites on your home network without having to configure a single computer or device. It’s the easiest way and provides the widest coverage since you’re blocking the websites at the source. If you have any questions, post a comment and I’ll try to help. Enjoy!

How to Block Websites With Linksys Wireless Router Read more: How to Block Websites With Linksys Wireless Router

A wireless router communicates with all computers in the wireless network over radio links; it also communicates those computers to the outside world, by way of a wired network backbone -- a cable modem connection provided by an Internet service provider. Since the router can access every request for Web pages issued from any computer in the wireless network, it can keep track of all accesses to websites. You can use a feature built into Linksys wireless routers to prevent users from accessing certain websites of your choice.

Instructions

1. • 1
     Connect your computer to any of the ports labeled with a number on the back of the Linksys router.
   • 2
     Log in to the computer.
   • 
     
   • 3
     Launch a Web browser by double-clicking on its desktop icon. Navigate with the browser to the router's configuration utility. The Web address for the configuration utility depends on the model. For example, a Linksys WRT54GS has its configuration utility listening at address "192.168.1.1".
   • 4
     Navigate to the menu section of the configuration utility where you can block websites. For example, for a WRT54GS, click "Access Restrictions."
   • 5
     Type the Web addresses of the websites you want to block in the appropriate fields, then save the configuration to the router so that changes become permanent. For example, on a WRT54GS, type the addresses of up to 4 websites into the fields in the "Website Blocking by URL Address" section. Click on "Save Settings." After that point, the Linksys router will no longer allow requests from the blocked websites to reach the outside world.

Read more: How to Block Websites With Linksys Wireless Router | eHow.com http://www.ehow.com/how_8423621_block-websites-linksys-wireless-router.html#ixzz2O8Xun3hH

How to Filter Websites Using Wireless Router

How to Filter Websites Using Belkin N Wireless Router

by Ruri Ranbe, Demand Media

Most modern Belkin routers use 802.11n -- the technical name for Wireless N signals -- to communicate wirelessly with other devices. Compared to previous wireless standards, such as Wireless B, Wireless N is faster and offers improved signal strength. Some Wireless N Belkin routers come with a Web filter that enables users to block certain websites. Companies can enable the filter on the router to prevent employees from accessing malicious sites that could potentially harm workstations on the network.

Step 1

Launch a Web browser and type "http://router" or "192.168.2.1" (without quotes) into the address bar. Press "Enter" to access the router administration page.

Step 2

Click "Login."

Step 3

Leave the password field blank and click "Submit" to sign in to the Belkin router.

Step 4

Choose "Website Filters" from under Parental Controls.

Step 5

Select "Block Malicious, Adult or Other Non-Family Friendly Sites," "Block Malicious and Adult Sites" or "Block Malicious Sites" from the options, depending on your preferences.

Step 6

Click "Apply Changes" to configure the Web filter on the Wireless N router.