In the recent years more and more wireless providers have started to provide femtocells to their customers. The customer can deploy the femtocell in any location that the coverage of normal towers are weak or absent.  Consider a product like Samsung’s Ubicell. The user can plug this femtocell in their home internet switch, and use their regular cell phone to connect to the final service provider, e.g. Sprint.

E-UTRAN architecture from 3GPP document 36.300-880

As of December 2008, 3GPP documentation for Long Term Evolution networks has started to mention Home eNB as part of the Evolved UTRAN. This move can be a significant advantage for the final users, only if service providers fully recognize the extent of service this final addition can offer. This recognition might require a careful study of 802.11a/b/g Access Points, considering the similarities of the two products. Both these products are the front end of a network to final customers. While these final points are accessible to the customers, the actual network is not controlled by them.

Most APs initially were merely wireless transmitters, but they soon started evolving into more sophisticated equipments. The need to provide more functionality for the end user to adjust settings, e.g. channel or user access rules, resulted in simple interfaces to configure the AP. Currently wireless APs are commonly acting as firewalls, switches, DSL modems.  But the true revolution for the APs happened when vendors such as Linksys started to provide open source firmware for their products. Because of the delay in this revolution, many golden opportunities are gone and we do not see as many diverse applications.

Given how larger organization such as universities might consider deploying a number of Home eNBs throughout their campus, there is a high level of interaction that would be only limited to these eNBs. As an example, in a university campus many calls and data interactions would be between students on the same area. Or consider an event like SXSW. While this year AT&T added enough resources to guarantee good coverage, smaller scale events do not motivate service provider to make such adjustments. Instead the organizing institute is well aware of the scale and the available resources and would be able to allocate more eNBs to the event area. One other aspect is access control: if I am paying for a Home eNB, I may not want my neighbor to user it for free unless it is an emergency call.

By providing good configuration options to the deploying organization, all sides of such scenario would benefit: the organization would enjoy faster service on their campus, the service provider would not have to worry about resource management and the manufacturer would ensure better sale of its products.

There are many challenges in providing such control to the final user. However, I believe the designers of 3GPP LTE have started taking initial steps and now the manufacturers need to move forward.

Related:

• Sprint Airave
• T-Mobile @Home
• Verizon Wireless Network Extender
• AT&T: 3G Microcell?
  
• Femtocells for Everyone
  

Unfortunately some of the people who actually design ATM machines have not passed this course it seems. Last Wednesday I withdrew some cash from an ordinary ATM, and the machine failed to return my cash. But my account balance was reduced! The machine actually was able to tell me that it had failed and the operation was canceled, but it seems it forgot to tell its friends back in the Wells Fargo network to cancel the operation. I had to call the customer service a couple of times to get my money back.

There is no conclusion from this post. It just surprised me that a simple basic idea we are taught in classes is not actually implemented in real life.

UPDATE: My old friend Pooya asked in the comments if the ATM in question was a Diebold ATM. Diebold is the company that also makes voting machines in US. Next time I was in Student Union I checked the ATM, and guess what: it is a Diebold ATM! I now have some serious questions in my mind!

I should mention that Wells Fargo checking people were very nice and quick and solved my issue by a couple of phone calls.

CMMI, from my point of view, is the key to solving this problem. If this model is used it focuses on identifying processes, refining them and then keeps tuning them and revising them over time. This way you can expect to reach your standards after a time, instead of wildly applying different software engineering methods.

During my Software Project Management course with Dr. Mili, me and my two other teammates Jason and Shiva did a presentation on the CMMI topic. This was one of the many topics covered in the course, some of them by students in the form of presentations. I had already taken this course during my undergrad, but my short work experience showed me how important it is to know these things. From my point of view, this course is one of the things that distinguishes a manager from a developer. Also knowing topics covered in this course enables you to talk to higher management fluently.

Anyways, we used a Subversion repository for revision control. It was not very efficient in terms of conflict resolution because of the fact that we could not use diff on powerpoint files. But using subversion was definitely advantageous since we could update each other without sending messy emails with huge attachments.

The final presentation is available here, printable version here. I highly recommend the course in case you are considering computer related jobs in future.

A digg user posted an item about a HD-DVD code, and the fact it was taken down because of a takedown notice. Digg removed that. People noticed that and informed each other of Digg’s removing the dugg story. But Digg removed those too. People dugg all of this again, Digg un-dugged. People dugg, ….

The result? Look at this:

You think it is over? NO! The same is happening with Wikipedia: http://en.wikipedia.org/wiki/HDDVD_Night. People [write in] wiki, Wiki removes. People (write in) wiki, ….

Even in something like this some people show courage:

Liviu Librescu, 76, an engineering science and mathematics lecturer, tried to stop the gunman from entering his classroom by blocking the door before he was fatally shot, his son said Tuesday from Tel Aviv. [Yahoo! news]

I truly sympathize with families of the victims.

• Time.com Report
• UT Dallas Responds
• Iran expressing sentiments of condolence
  

Is it only me who thinks so, or is it kind of silly?

Does God …
… exist?
… play dice?
… love me?
… change his mind?
… answer prayers?

I just localized the idea and asked for suggestions about Iran. See the results:

does iran …
…have nuclear weapons …have nukes …have oil

is iran …
…next …a democracy …a threat …a nuclear threat …arab …the next target …an islamic state …an arab country …arabic …a thecracy

why iran …
…hates israel …hates us …is next …next …wants nuclear weapons

how iran …
…will fight back

will iran …
…be next …be next fallows …be attacked

I don’t know if to consider these funny, or sad?

It seems that YouTube is playing a very interesting role in LA this year:

“Californians are entitled to more transparency than a chance video,” said Ramona Ripston, executive director of the ACLU of Southern California. “YouTube is not an acceptable substitute for accountability.”

Morals of the story:
1-Students are very likely to do very very stupid things, like not showing an ID or whatever. Reason? They are young and have not much experience. But responding that with something like Tasing them is far more stupid and meaningless.
2-Combination of YouTube and Cell phone camera means real media.

PS: A witness says in NBC4 article:

I can just say that he was willing to leave. He had his backpack on his shoulder and he was walking out when the cops approached him. It was unnecessary.

Put contents of this zip file in the directory you want to be protected. Read the files and change what seems necessary. On your web pages, where you are going to have media content in, change the source path and add this in the head section:

   <script src="/path/to/hotlinkp.js" type='text/javascript'>
   </script>
 

Anywhere you want an embed object added, just add this:

   <script>
       make_link("458","Anathema: A Simple Mistake<BR>");
   </script>
 

It can be modified easily to do whatever you need. Leave me a comment if you need help on it.
NOTE: I intended to add more features, but didn’t find neither the time nor a reason to do so, and then release it. If someone needs something of it, I’ll be glad to add features.

To read the full step by step creation of these,

A friend of mine publishes different sorts of digital content on his website/weblog. His main intention is to have embedded audio files in his blog, just to make it easier for the viewer to listen them. His daily traffic has reached 4GB to 6GB per day. For instance on 01 August 2006, he had 3682 visits equal to 30239 hits consuming 6.38 GB of bandwidth. Detail of the accessed files?

• 48.4 % Audio
• 37.3 % Image
• Third place is HTML or XML static page with 12.7 % share of the hits.

This amound of hits/visits generates a ~390GB monthly bandwidth usage which is way too close to his bandwidth limits.

A closer look at his log files showed most of the traffic originated from search engines, mp3/wma search engines and especially hot linking of other people. If you don’t know about hot linking here is a good intro on hit linking:

Hot linking is probable one of the most popular ways for users to steal bandwidth and copyrighted material from other webmasters. Basically anything that someone links to, that resides on another user’s web hosting account is considered hot linking. Users also call it Leeching. This can be anything from images to files.

We step by step compiled necessary scripts to block hot linkers and mp3/wma search engines or even google to access the copyrighted material. If you have the same problem, this might be usefull to you too. To use the same method, you must be running Apache web server with mod_rewrite enabled, able to run php scripts. If you do not have Apache, you can convert it to work for you. The concept is quiet the same.

After using this method, the traffic dropped from 383GB in July to 189GB in August. In September, traffic decreased to 139.84 GB. Daily average was 8.99 GB in July which is 4.85 GB in August,and 4.66 GB in September.

Step 1

Well, first of all we added a simple javascript function. It would generate the download links of audio files, mostly .WMA files, and also the embed html tags required. The concept was something like this:

   function make_link(name)
   {
   var server="www.mydoamin.com";		//change this
   var dir="/blog/songs/";			//change this
   var link="http://"+server+dir+name;
   var link+=".w"+"m"+"a";			//change this
   var embed="<br /><br /><embed pluginspage=http://www.microsoft.com/Windows/MediaPlayer/ src=\"";
   embed+=link;
   embed+="\" width=70 height=26 type=\"application/x-mplayer2\"";
   embed+=" ShowControls=\"1\" autostart=\"0\" loop=\"0\"><br />";
   document.write(embed);
   }

As a result, after a while search phrases like "Song XYZ filetype:wma" would no longer point to his site in search engines like Google.

Step 2

This time we had to remove the hot linkers of images. This can be done easily using cPanel’s integrated hot link protector. If not using cPanel, this .htacces would do good:

	RewriteEngine on
	RewriteCond %{HTTP_REFERER} !^http(s)?://(www\.)?yourdomain.com [NC]
	RewriteRule \.(jpg|jpeg|png|gif)$ - [NC,F,L]

You can generate a usefull .htaccess on this site. Just place the resulting .htaccess in the directory where your content is residing.

Step 3

NetShow Player (media player) counted for 50 % of the hits in (for instance) July 2006. This is equal to 140GB of the bandwidth! How much of this is our own visitors? Not much I guess. Most of it from people embedding audio files in their homepages.

Hot link protection of images may be simple, but what about embedded objects? NetShow player, Windows Media Player, Real Player and other similar ones usually do not send referrer data to the web server. Look at this line of access log on that server:

   85.182.xx.yyy - - [07/Aug/2006:02:51:23 -0600] "GET /blog/songs/243.wma HTTP/1.1" 200 30679 "-" "NSPlayer/10.0.0.3646"

This means that someone with IP address 85.182.xx.yyy has tried to "GET /blog/songs/243.wma". It has got a 200 status code, means it was OK for him to do so. 30679 bytes were transfered. No referrer data has been sent, the "-" after the indicates. The user agent, browser, has been NSPlayer which is NetShow Player. Since it has not sent a referrer the regular hot link protection based on referrer is useless. If we use that .htaccess trick here, even content on our own pages won’t work.

To stop others from putting our content on their pages using embed method, we did the following:

1-Added afunction called encrypt to our pages:

   function Encrypt(theText)
   {
		num_out = "";
		str_in = escape(theText);
		for(i = 0; i < str_in.length; i++)
		{
		   num_out += str_in.charCodeAt(i) - 23;
		}
		return num_out;
   }

2-Changed the make_link(name,desc) javascript function to something like this:

function make_link(fm,desc)
   {
		var d = new Date()
		var t= d.getFullYear()+"/"+(d.getMonth()+1)+"/"+d.getDate();
		t=encodeURI(Encrypt(t));
		var server="www.mydoamin.com";		//change this
		var dir="/blog/songs/";			//change this
		var link="http://"+server+dir+name;
		var link+=".w"+"m"+"a";			//change this
		var embed="<br /><br /><center>";
		embed+="<embed pluginspage=http://www.microsoft.com/Windows/MediaPlayer/ src=\"";
		embed+=link;
		embed+="\" width=70 height=26 type=\"application/x-mplayer2\"";
		embed+=" ShowControls=\"1\" autostart=\"0\" loop=\"0\"><br />";
		address="<a style=\"font-style: tahoma, arial; font-size:80%\" href=\"";
		address+=link;
		address+="/"+t+".wma";
		address+="\">";
		address+=desc;
		address+="</a></center>";
		document.write(link+address);
   }

3-In the .htaccess, I forbid direct access to the .wma filetypes. Only requests matching the pattern created by the javascript function were redirected to a PHP script:

		RewriteEngine on
		RewriteRule ^(.*)\.wma/([^\.wma]*)\.wma$  redirect.php?file=$1&t=$2 [nc]
		RewriteCond %{REQUEST_URI} ^(.*)/([0-9]{1,4})\.wma$
		RewriteRule ^(.*)$   - [f,nc]

This way, a link like http://www.mysite.com/blog/songs/1234.wma/12345678.wma would be translated to a request like http://www.mysite.com/blog/songs/redirect.php?file=1234&t=12345678
and the red.php is something like this:

 <?php
$myDoaminNames=array("mysite.com","mysite2.com");	//a list of different doamin names I have
$myExtension=".wma";								//extension of files: .wma/.mp3/.mpeg/...
$myTimeLimit=86400;									//the amount of time the code is valid in seconds

//this function unencrupts the digital code generated by the JS
   function unEncrypt($str)
   {
	   for($i = 0; $i < strlen($str); $i += 2)
	   {
		   $num_in = (int)(substr($str,$i,2)) + 23;
		   $str_out .=chr($num_in);
	   }
	   return $str_out;
   }
	$t=($_GET['t']);		//get the code
	$filename=$_GET['file'];	//get the filename desired
        $file=$filename.$myExtension;
	if (!is_file($file))		//catch non-existant file requests
	{
	   header("HTTP/1.0 404 Not Found");
	   die();
	}
	$t2=unEncrypt($t);		//Attention: TIME OF BROWSER'S CLOCK!
							//user could be in Iran, server could be in USA
	$now = date("Y/m/d");	     	//Attention: LOCAL TIME of server
	$diff=strtotime($t2)-strtotime($now);
	//we give people one day chance to use the same download `code`
	if ($diff > 86400 or $diff < -86400)
		$expired=true;
	else
		$expired=false;

	//which browser is requesting? Firefox? IE? NSPlayer? RealPlayer?
	$browser=$_SERVER['HTTP_USER_AGENT'];
	//what referrer data is sent to us?
	$referer=$_SERVER['HTTP_REFERER'];		

	if (stristr($browser,"NSPlayer") || stristr($browser,"Media") )
		$embed=true;
	else
		$embed=false;
	if (in_array($referer,$myDoaminNames))
		$ref=true;
	else
		$ref=false;
	//if referrer is set and is OK, or it is an embedded content AND the code is not expired
	if ($ref || ($embed && $expired==false) )
	{
		header('Content-disposition: attachment;   filename="'.$file.'"');
		header('Content-Type: audio/x-ms-wma;');
		header('Pragma: anytextexeptno-cache', true);
		header('Content-Transfer-Encoding: Binary');
		header('Content-length: '.filesize($file));
		readfile($file);
	}
	else
	{
	   /*
	   just to test, needs a writeable file called log in the same directiry to write logs into it
	   $fp=fopen("log",a);
	   fwrite($fp,print_r($_SERVER,1)."\n");
	   fwrite($fp,"embed=".$embed."\n t2=".$t2."\n && expired=$expired\n--\n");
	   fclose($fp);
	   */
	   echo ">h1<leeching not permitted>/h1<";
	}
?>

Alternative method

If all of your pages are written in PHP, or any other dynamic programming language, you register IP addresses of visitors and let them download only if their IP address appears in the recent visitor list. The idea is similar to session tracking, but this time no data is kept on user side.

Improvement

• Make the random generator function a web service, and make it available only to your own web server.
• Give each file type a code, and then while requesting swend this code too.
• Double check the .htaccess rules. Some file names may not match the forbidding rule, hence people can access them.