Guayaquil goes Wi-Fi
Juan Pueblo is an allegoric figure and a emblematic character of our city, Guayaquil
Some good news for the fellow citizens interested in Wi-Fi and Wireless Technologies: the City Hall of Guayaquil has started a project called “Guayaquil Digital”, which is essentially the deployment of free Wi-Fi along parks, schools and colleges within Guayaquil, my home city.
From this month, three high schools, three Universities and two near zones will benefit from this project. While the service has a limited backhaul (internet) bandwidth -1 or 2 Mbps-, it’s still enough to cover some of the student needs.
One drawback so far seems to be the number of Access Points that will be installed and thus the complete coverage that they will provide. The Vicente Rocafuerte high school’s rector, for instance, stated that although they have been told that 2 Access Points will be installed, they are not aware of the total coverage that they will provide yet.
This rises up the question of whether a limited internet bandwidth along with a limited number of Access Points will ultimately deliver an appropriate service that will meet the students’ needs or not. Some problems that could arise from this type of installation would be the excessive number of students per Access Point, or an excessive coverage that would give a poor service on far distances, between many others.
My concern is based on what Jaime Nebot, Mayor of Guayaquil, said, a kind of black or white statement: “it’s simple, it works or it doesn’t work. You sit down in your high school or park, open your laptop and if you have a wireless internet connection, it works. If not, it doesn’t”, referring to the fact that in these two-year service contract with Telconet will be continuously evaluated. In the long run, chances are that the number of students using the service will increase are high, and capacity will some day become a bigger concern.
Nonetheless, my overall score for this initiative is positive, and I hope that the City Hall will continue with this project to provide Wi-Fi coverage to other zones within the city.
[Solved] That Atheros AR9285 WLAN Card Problem
About six months ago, I bought this awesome Samsung laptop at a great price. It’s been working just great, the only problem has been the WLAN card. It’s an Atheros AR9285 802.11a/b/g/n. At the beginning it worked fine, but lately it’s been failing like mad: it randomly loses connectivity from the WiFi network, although Windows stated otherwise.
I quickly thought it should have been a driver issue, so I looked for one that would do the job, and I found it at HP’s support website. Since it’s just a driver, it wouldn’t be a problem, right?
Here is the driver’s link: It’s for an AR9285 WLAN card running under a 64-bit Windows 7 (be sure to read that)
In case you don’t know how to install it, here’s how to:
- Extract its contents and then, under network connections, get in the properties of your wlan card
- Click on configure
- Then click on driver’s tab and then click on update driver
- Now click on Browse my computer for driver software.
- Click on the “Let me pick from a list…”
- Click on “Have a disk” and then click on browse, and search for the netathr.inf file. Then next.
- Select AR9285 802.11a/b/g/n from the list, then next. That should install it.
It works great now. It was just a matter of updating the driver, but looking for the right one is a real pain in the neck. Let me know if it works for you too.
A Proximity-Aware Transparent Handoff Mobility Scheme for VoWMN (PATH)
Last year, I dedicated an important part of my work and time at the research center of my University to develop a way to provide fast handoffs within a 802.11s network. This post briefly describes it, named PATH after several attempts to make it sound cool.
Related Work
Most of the inspiration came from a great and interesting project called SMesh, a fast handoff mobility system created by the DSN Labs staff at Johns Hopkins University. One of the people behind the system is @ralucam, who helped me to understand the protocols of this system.
Yet another work that was taken into consideration is LCMIM, which is a Light-weight Client Mobility approach for Infrastructure Mesh networks. It is basically a simpler solution than SMesh but it is somewhat inefficient as it continuosly contends for the medium by broadcasting gARP messages, flooding the channel even though no Client is really using the network and that is bound to be used with a reactive routing protocol, in the case presented in the paper, AODV. The good side is that its nodes maintain independence and that it’s a simpler solution as well.
The PATH scheme
After several months of hard work and going through a learning process, I developed PATH, a Proximity-Aware Transparent Handoff mobility scheme. I should state that it is by no means a solution as complex and complete as SMesh as it only addresses the reversed channel latency issues caused by handoffs, but it certainly is simpler to install, follows a simpler logic and is independent of the type of routing protocol used as well.
The paper that describes its procedures has been recently accepted in INTERCON 2011, in Peru, for publication. I’ve shared the presentation here:
It all went good. It basically sends gARP messages based on client proximity (which is measured by the perceived RSSI on each node), thus associating clients to new nodes and switching its connectivity. Take a read to the presentation!. It should be noted that all three: SMesh, LCMIM and PATH create an infrastructure Mesh Network by setting wireless nodes into adhoc mode. By using this mode, all three schemes do not let the client decide when to roam but leave the responsibility to the network nodes.
It was designed to provide fast handoffs for real-time voice applications. Although it is essentially a work in progress and there are lots of ways to improve the scheme, I had the opportunity to share the results and they were all great 
I will be posting a link to the paper soon!. Hope you like the presentation.
Just started a new Game Dev blog
Hey! I just started a new blog. No, I won’t leave or quit this one! it’s just about a hobby that I’ve recently (and finally) started. After some years of programming experience and a childhood dream of writing a game, I finally started doing this as a hobby.
I hope you like it: http://nullbox.wordpress.com
Cheers
How to make Soundboard Prank Calls using Skype
I know this is pretty off-topic in my blog, but I wanted to share it with you
I was wondering: how to play sounds in skype when calling someone? Yeah like on those youtube videos featuring soundboard prank calls of Arnold Schwarzenegger. I just found how to. Is not that I want to do it… really… I mean, I haven’t done it in my life… ever.
But ok. Let’s start with what you need.
- You need Skype, obviously.
- A fair set of wav/mp3/whatever-extension-you-want clips, you can find lots here
- Windows 7 for this howto
First, go to start > control panel > hardware and sound > sound > recording. Right-click anywhere to show a menu and click on “show disabled devices”… “Stereo Mix” will appear. Right click on Stereo Mix and click on enable.
then right-click on Stereo Mix and click on enable
Now open Skype. If Skype asks you to add “Stereo Mix” click on yes.
Click on “Settings” and then click on the microphone button. Select “Stereo Mix” from the popup menu. What you’re doing right here is telling skype to use the sounds that are being played on the computer over a call.
select stereo mix as the mic input
You’re done! If you want to test it, make a call to the Sound Test Service. It will ask you to say something after the beep and that it will be played back afterwards.
Just open the sound clip file you want (play it), it will be played on the call (give it a try).
This howto was obviously made to have some fun with your friends. I hope that you don’t know that skype lets you call to Toll-Free numbers in the US for free and that you can actually make free prank calls with skype. oops
Until next time
