Facebook Friends and Frenemies Report - Why We Add and Remove

There's a new Facebook research report from Nielsen McKinsey's NM Incite titled Friends & Frenemies: Why We Add and Remove Facebook Friends that's pretty interesting. The report looks at the factors that help Facebook users decide whether they want to add someone as a friend or remove an existing person the their friend list. Here's a few details:

• Knowing someone in real life is the top reason cited for friend-ing someone (82%)
• Offensive comments are the main reason someone gets the boot (55%)

Additional report details suggests that real world interactions drive online friendships. Meanwhile, sales-oriented and depressing comments help drive friend removals. Facebook etiquette also plays a role, with updating too often, too little or having too many friends a consideration for some Facebook users.

Regarding gender, the report research indicates that men are more likely to use social media for careers/networking and dating – while women use social media for a creative outlet, to get coupons/promos or to give positive feedback. More men add friends based on business networks or physical attractiveness and women are more likely to friend based on knowing someone in real life or remove them due to offensive comments.

Here's an interesting infographic from the report.

What's a T3 Line?

In my last post I described what a T1, also called a DS-1, line was. Most of us have also heard the "T3 Line" term used. Let's take a look at what a T3 or DS-3 line is.

DS-2 Signal
Before we can describe a DS-3 line, let's first take a look at a DS-2. In that last post we figured out how each DS-1 signal (T1 line or circuit) carries a bit rate of 1.544 Mbps. Four 1.544 Mbps digital DS-1 signals are multiplexed into one DS-2 signal. If we have 4 DS-1 signals per DS-2 signal and each DS-1 signal is 1.544 Mbps we can calculate:

Adding overhead consisting of timing and synchronization bits brings the DS-2 bit rate to 6.312 Mbps.

DS-2 Formation

DS-3 Signal

Each DS-2 signal carries a bit rate of 6.312 Mbps. Seven 6.312 Mbps digital DS-2 signals are multiplexed into one DS-3 signal. If we have 7 DS-2 signals per DS-3 signal and each DS-2 signal is 6.312 Mbps we can calculate:

Adding overhead consisting of timing and synchronization bits brings the DS-3 bit rate to 44.736 Mbps.

And..... 44.736 Mbps.... that's a T-3 line!

T1 Lines - What They Are

Most of us have heard about "T1" lines. We know they are some kind of (expensive) communications line you can get from one of the telephone companies. It turns out T1's are part of the Digital Signal (DS) Level System. 

Back in August, I wrote a post titled More on CODECs: Quantization + Sampling Rate = A PCM Wave. In that post I described how a piece of an analog signal is quantized and companded and then given an 8 bit binary code in a process referred to as encoding. From that post, we know to convert an analog signal to a digital signal the analog signal is sampled 8000 times per second and, after matching the instantaneous voltage sample level to one of 256 discrete levels, an 8 bit code is generated for each sample. If we multiply the sample rate by the bit code we get:

(8000 samples/second)(8 bits/sample) = 64,000 bits per second (bps)

So we can say a single analog voice channel, after conversion from analog to digital, requires 64Kbps of digital bandwidth. This 64Kbps is referred to as Digital Signal Level 0 (DS-0) and is the basic building block or channel for the existing digitally multiplexed T carrier system in the United States and the digital E carrier system used in Europe. 

Voice calls are digitally multiplexed using either time division multiplexing or statistical time division multiplexing. Calls are grouped in a way similar to frequency division multiplexing. Let’s look at how this is done.

Digroups or DS-1 signals

Individual analog voice call channels converted to digital and require a bit rate of 64 Kbps each. 24 64 Kbps digital voice channels are multiplexed into digroups or DS-1 signals. If we have 24 DS-0 signals per DS-1 signal and each channel is 64 Kbps we can calculate:

Adding overhead consisting of timing and synchronization bits brings the DS-1 bit rate to 1.544 Mbps - that's a T1!

DS-1 Formation

DS-1 Overhead

We’ve described the process of encoding where an analog signal is sampled 8000 times per second, quantized into one of 256 discrete signal levels, companded it is then given an 8 bit binary code. After a single analog signal sample has been encoded it is multiplexed, with 24 other encoded 8 bit sample signals. This generates a 192 bit (8 bits/sample signal × 24 sample signals) sequence for the 24 sample signals. A process called framing then adds one framing bit to create a 193 bit frame.

DS-1 With Overhead

The framing bits are used to keep the receiving device in synch with the frames it is receiving. Every twelve frames are grouped into a masterframe, also referred to as a superframe. Included within each masterframe is a twelve bit frame pattern from the 12 grouped 193 bit frames This twelve bit frame pattern carries a bit pattern of 000110111001 and repeats itself with each masterframe.

Masterframe

This masterframe bit pattern is used for synchronization.

Remember each channel is sampled 8000 times per second so a single frame represents one eight-thousandth of 24 individual channels or telephone calls. We can also say that, in one second a DS-1 signal transmits 8000 193 bit frames. We can use these numbers to calculate the true DS-1 bit rate which includes both data and overhead (framing) bits:

Each DS-1 signal carries a bit rate of 1.544 Mbps and.... that's a T1!

Carrier IQ - are You Being Tracked?

Last month, security researcher Trevor Eckhart published a report accusing CarrierIQ of installing malware on more than 140 million devices worldwide. Eckhart also published a video showing CIQ's software secretly running in the background and monitoring a variety of handset activity on an HTC device including key presses, browsing history, SMS logs, and location data. If you have not seen it, here's Part 2 of Trevor's video: 



Yesterday Senator Al Franken from Minnesota "reached out" to AT&T, HTC, Samsung, and Sprint Nextel after they acknowledged their use of Carrier IQ’s diagnostic software to request that they explain (within the next 12 days) what they do with the information they receive from the software.
Also yesterday, Carrier IQ released a statement saying:

We measure and summarize performance of the device to assist Operators in delivering better service. While a few individuals have identified that there is a great deal of information available to the Carrier IQ software inside the handset, our software does not record, store or transmit the contents of SMS messages, email, photographs, audio or video. For example, we understand whether an SMS was sent accurately, but do not record or transmit the content of the SMS. We know which applications are draining your battery, but do not capture the screen.

In addition, the following updates have been posted by The Huffington Post:

Grant Paul, a well-known iPhone hacker who goes by the screenname "chpwn",wrote on his blog that Apple has included Carrier IQ on the iPhone, but the software's default is disabled.  

Want to find out if your phone is secretly tracking you? Check out our comprehensive list of the devices and carriers known to use Carrier IQ.

Who And Why I Follow Back on Twitter

Catching up on some work this morning and going through new people that started following me over the past two weeks.  I've got my account setup so I get email notification when someone follows me and I look at each one, determining whether I want to follow back. Out of the 302 new followers I picked up in the past couple of weeks, I followed back only 27 this morning. That's only 8.95% and it is pretty typical.

Here's how I personally sort this stuff out:

When someone follows my feed I've got Twitter setup to send me an email notification.
I've got my email client (Thunderbird) setup to automatically move those Twitter email notifications to a separate Twitter folder. When I have some time (like this morning) I go through the notifications, determining whether I want to follow back. Here's my follow-back determination procedure:

1. I've got Thunderbird setup to preview email. The first thing I look for is a name (a person) attached to the account. If I don't know your organization and there is no name listed, I'm probably not going to follow back. Some details:

• I try and only follow back those with similar interests, these interests can be both work and hobby related. If you are a business, organization, academic institution or individual involved in Science, Technology Engineering or Math (STEM) I'm definitely following you back. I'll also follow you back if you are focused on one of my hobbies - for example - saltwater flyfishing. 
• Sorry but religion and politics are always a do not follow back red flag for me. I know many use Twitter and other social media for this kind of stuff and I don't have a problem with that. It's just not what I personally use it for.

2. If I like what I see in the email preview I'll click the link to your feed and take a look at the last 5 or so posts. If it is junk - spam, any hint of profanity, etc. Done - I'm not following you. The best chance for a follow back is if you have something posted I'm interested in. Maybe it is a short description with a link to an interesting post on the web. If it is something I really like and retweet it, you are definitely getting a follow back.

3. There are some exceptions and I typically follow back the following:

• Local businesses (not based on religion or politics). This includes my favorite Pizza shop in Western Massachusetts. 
• Known organizations, like the National Science Foundation (of course!)
• Some celebrities - how could you not follow back someone like Weird Al Yankovic? 
• Old friends and sometimes friends of friends if I can sort the connections out. 

4. Once I start following you - if I do see any spam, profanity, religion, politics I'm un-following you. I also occasionally go in and cull the list of people I follow and this is the kind of stuff I'm looking for.

 So..... back to my experience today - only 27 follow backs out of 302 new followers..... 8.95%. Yes - there is a lot of junk out there but..... mixed in with the junk there is a lot of good stuff.

You can follow me on Twitter at www.twitter.com/gsnyder

Wavelength Division Multiplexing (WDM)

In my last legacy Public Switched Telephone Network (PSTN) post I covered Statistical Time Division Multiplexing (STDM).  In this post let's take a look at Wavelength Division Multiplexing (WDM and DWDM) methods.

As bandwidth requirements continue to grow for both the legacy Public Switched Telephone Network and the emerged Internet/IP network most of the high bandwidth backbone transmission is being done with fiber optics and a method called Wavelength Division Multiplexing or WDM. WDM functions very similarly to Frequency Division Multiplexing (FDM). With FDM different frequencies represent different communications channels with transmission done on copper or microwaves. WDM uses wavelength instead of frequency to differentiate the different communications channels.

Wavelength

Light is sinusoidal in nature and wavelength, represented by the Greek letter lambda (λ) is a distance measurement usually expressed in meters. Wavelength  is defined as the distance in meters of one sinusoidal cycle.

Wavelength Measurement

Wavelength indicates the color of light. For example, the human eye can see light ranging in frequency from approximately 380 nm (dark violet) to approximately 765 nm (red). WDM multiplexers use wavelength, or color, of light to combine signal channels onto a single piece of optical fiber. Each WDM signal is separated by wavelength “guardbands” to protect from signal crossover. One of WDM’s biggest advantages is that it allows incoming high bandwidth signal carriers that have already been multiplexed to be multiplexed together again and transmitted long distances over one piece of fiber.

Wavelength Division Multiplexing

In addition to WDM systems engineers have developed even higher capacity Dense Wavelength Division Multiplexing (DWDM) systems. Just this past week, Cisco and US Signal announced the successful completion of the first 100 Gigabit (100G) coherent DWDM trial. As backbone bandwidth requirements continue to grow these WDM and DWDM systems are significantly reducing long haul bandwidth bottlenecks.

Podcast - Why We Are Not Google: Lessons from a Library Web site Usability Study

Back in September I had the chance to interview Troy Swanson, an Associate Professor / Teaching and Learning Librarian at Moraine Valley Community College in Palos Hills, IL. In the interview we discussed a paper he published with Public Service Librarian Jeremy Green, also at Moraine Valley Community College. Here's the abstract from that paper published at Elsevier's ScienceDirect.

In the Fall of 2009, the Moraine Valley Community College Library, using guidelines developed by Jakob Nielsen, conducted a usability study to determine how students were using the library Web site and to inform the redesign of the Web site. The authors found that Moraine Valley's current gateway design was a more effective access point to library resources than a mock-up site which incorporated a central-search box on the site homepage. This finding stands in contrast to the observed trends of library Web site design that emphasizes a “Googlized” search.

Troy and Jeremy's findings are very interesting, especially if you are managing/modifying an existing site or are considering creating one. 

You can listen here:

Here's the links Troy refers to in the podcast:

The Next Level (Blockbuster article)by James Surowiecki

• http://www.newyorker.com/talk/financial/2010/10/18/101018ta_talk_surowiecki

useit.com: Jakob Nielsen's Website

• http://www.useit.com/

The Googlization of Everything (book review)

• http://www.googlizationofeverything.com/

Why We Are Not Google: Lessons from a Library Web site Usability Study

• http://www.sciencedirect.com/science/article/pii/S0099133311000280

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