Verizon FiOS Buildout Essentially Done, Fixed LTE Coming

In a quarterly earnings conference call last Friday Verizon confirmed a couple of things I've been saying here for the past couple of years. The FiOS build out is basically done for now and Verizon Wireless will be offerring a fixed LTE option in direct competition with the landlind side of the business.

Here's an interesting Q&A from the VZ - Q3 2011 Verizon Communications Inc Earnings Conference Call held on October 21, as posted at DSL Reports:

Citigroup Analyst: Is there any thought of taking that non-FiOS bundle of presumably LTE broadband LTE voice,what about taking that more nationally and making that more of a national product for you versus just maybe an out of FiOS region but in territory Verizon product? 

Fran Shammo: Well, we are. And you're going to see that come in the fourth quarter with the -- what we now call the Cantenna which is not a commercial name obviously, but it's the antenna that we actually trialed with DIRECTV, which was extremely successful. And again, the benefit of this antenna is it operates the spectrum extremely efficiently. So if you look at a MiFi card or a dongle, this is very, very efficient, way above those two devices which is why it's critical to have that bundle with that Cantenna. So when we launch that you're going to see us go nationally with that type of an offer.

Analog or Frequency Multiplexing

In this post I continue discussing some of the different legacy technologies used by the Public Switched Telephone Network (PSTN). Today let's take a dive into analog or frequency multiplexing.

Analog or frequency multiplexing is now an obsolete technology in the U.S. telecommunications industry. It was used up until the early 1990’s by long-distance carriers like AT&T and MCI and is still used today in other countries. The concept of channel banks was developed for analog multiplexing and this concept is still used today for other types of multiplexing. To multiplex calls each call was given a narrow range of frequency in the available bandwidth. We know all voice call channels occupy the same frequency range – approximately 4000 Hz if we include individual call guardbands. If we want to combine a group of voice calls and separate them by frequency we must translate the frequency of these individual call channels using a process called Single Sideband, Suppressed Carrier Modulation. This technique allowed 10,800 individual voice call channels to be combined and transmitted over one coaxial copper pair. Let’s look at how it was done.

Groups

Individual voice call channels are placed into groups of 12. If we have 12 channels per group and each channel is 4000 Hz we can calculate:

This 48KHz is placed in the frequency range of 60 – 108 KHz. 

Single Group Formation

Supergroups

Individual groups are placed into supergroups of 5 and each supergroup contains 60 individual voice channels. If we have 5 groups and each group is 48 KHz we can calculate:

This 240KHz is placed in the frequency range of 312 – 552 KHz.

Supergroup Formation

Mastergroups

Individual supergroups are placed into mastergroups of 10 and each mastergroup contains 600 individual voice channels. If we have 10 supergroups and each supergroup is 240 KHz we can calculate:

This 2.40MHz is placed in the frequency range of 564 – 2.964 MHz.

Mastergroup Formation

Jumbogroups

Individual mastergroups are placed into jumbogroups of 6 and each jumbogroup contains 3600 individual voice channels. If we have 6 mastergroups and each mastergroup is 2.4 MHz we can calculate:

This 14.4 MHz is placed in the frequency range of 3.084 – 17.484 MHz.

Jumbogroup Formation

Jumbogroup Multiplex

The final multiplexing step involves combining individual jumbogroups which are placed into jumbogroup multiplexes of 3. Each jumbogroup multiplex contains 10,800 individual voice channels. I'm still amazed - 10,800 calls on one piece of coaxial cable!

Frequency multiplexing is now considered obsolete technology on the telecommunications network. Analog signals are more sensitive to noise and other signals which can cause problems along the transmission path. Those long coaxial cables make pretty good antennas. They have been replaced with digital multiplexers. In my next legacy PSTN post I'll cover how digital multiplexing works.

reference: Introduction to Telecommunications Networks by Gordon F Snyder Jr, 2002

Multiplexing - A Brief Introduction

In this post I continue discussing some of the different legacy technologies used by the Public Switched Telephone Network (PSTN). Today let's take a quick look at what multiplexing is.

Before the invention of the telephone both Alexander Graham Bell and Thomas Edison were experimenting with ways to transmit more than one telegraph signal at a time over a single wire. They both realized this was a critical piece if any communications network was to grow in the number of users.

Multiplexing

There are three ways to multiplex or combine multiple signals on the telephone network. They are analog or frequency multiplexing, digital multiplexing and wavelength division multiplexing. I'll dig pretty deep into each in upcoming legacy posts.

The SLC-96

In this post I continue discussing some of the different legacy technologies used by the Public Switched Telephone Network (PSTN). Today let's take a look at how the PSTN designed and tuned for voice communications started to change in the late 1970's with something called an SLC-96 (pronounced "Slick 96").

It's still not economical even today to run fiber into every home but Local Exchange Carriers like Verizon and AT&T have been working to replace portions of the local loop with fiber by running fiber out from the CO into a Remote Terminal (RT) pedestal box in the field called a Multiple Subscriber Line (or Loop) Carrier System or SLC-96. Each SLC-96 takes 96 64 Kbps analog voice or modem signals, converts them to digital and then multiplexes them at the Remote Terminal. The Remote Terminal is connected to a Central Office Terminal (COT) using 5 T1 (DS-1) lines. 

SLC-96 Field Pedestal Configuration

Four of these T1 lines are used to carry the 96 digitized voice channels (1 T1 line = 24 digitized voice channels so 4 T1’s are required to transmit 96 voice channels). The fifth T1 line is used for protective switching and is a backup if one of the four fails.

In my next legacy PSTN post I'll start covering multiplexing.

Hybrid-Terrestrial-Satellite Networks?

That's what Charlie Ergen at Dish Networks is putting together and it makes sense. Ergen's a former professional blackjack player billionaire currently transforming Dish to a wireless mobile video company. An October 17-23, 2011 Business Week Companies & Industries piece titled Charlie Ergen Wants To Beam You Everything does a nice job summarizing where Ergen is taking Dish. Here's some details.

Dish has spent over $5 billion this year on acquisitions of companies in bankruptcy. Here's three of the biggest:

• Blockbuster video chain - video content 
•  EchoStar set-top box maker - IP-based end device connectivity
• Hughes Communications  - satellite Internet service provider

Ergen moved fast with the Blockbuster acquisition, rolling out a Blockbuster branded movie streaming service to Dish customers last month. 

What's next? Ergen currently has a $1.9 billion offer on the books for Hulu which is currently owned by News Corp., Walt Disney and Comcast. Picking up Hulu would give Dish rights to more than one million paying subscribers.

Dish also has pending deals to pick up DBSD North America and TerreStar Networks. These two companies also own wireless spectrum which could be the real prize and an indication of things to come. What the company really needs is more wireless. Access to an existing broad wireless network (DBSD and TerreStar will not be enough) is coming so watch for Ergen to go after a provider (maybe Sprint?) or maybe cut a deal with one of the other providers (Verizon Wireless or AT&T?).

What about competition from companies like Netflix? Peter M. Hoffman from GHL is quoted in that Business Week piece "What Charlie's done is put together content and distribution. Netflix still has to rely on someone else's distribution to deliver its content."

Adding that wireless broadband piece (that Ergen needs for video delivery) could turn Dish into a viable broadband alternative to telcos like Verizon and cable companies like Time Warner. What really excites me is the access Dish could offer rural areas where there is currently not good broadband options.

New UMass President and Massachusetts Green High Performance Computing Center

I've written in the past about high performance computing in Western Massachusetts. 

I had the opportunity today to visit the Massachusetts Green High Performance Computing Center (MGHPCC) in Holyoke, MA. A small group of us toured the Center with new University of Massachusetts President Robert Caret. 
As a UMass Amherst grad (Class of 1979) I have to admit it was pretty cool to be among the group to introduce Dr Caret to High Performance Computing in the Pioneer Valley. I'd like to thank MGHPCC Executive Director John Goodhue for the invite to this special event. Here's a few pics I snapped during the tour. 

Mass Green High Perf Computing Center, a set on Flickr.

Go UMass! Go MGHPCC!

A Few Additional Telephone System Features

In this post I continue to describe the legacy Public Switched Telephone Network (PSTN), looking at a few other common telephone system features we are all used to having and relying on. These are additional handset signals and PIC. I would also want to include Caller ID here but I've already covered how it works in a previous post.

Some Common Handset Signals

We are all used to hearing these additional common signals coming from our telephone. 

Line Busy Signal - 480 Hz and 630 Hz tones on for .5 seconds and off for .5 seconds, then repeats. 

Block Signal - 480 Hz and 620 Hz tones on for .2 seconds and off for .3 seconds, then repeats. This signal is often referred to as fast busy.

Off-Hook - 1400 Hz, 2060 Hz, 2450 Hz and 2600 Hz tones on for .1 seconds and off for .1 seconds, then repeats with a duration of 40 seconds. This signal is designed to be heard from across a room and is very loud.

Preferred Interexchange Carrier (PIC)

Since the 1976 MCI ruling AT&T has been required to open the long distance market to other long distance providers. Prior to this, all long distance traffic in the United States was handled by AT&T and users would just dial a “1” to connect to an AT&T long distance trunk. As other long distance carriers entered the market, AT&T had a big advantage. Customers were already used to dialing a “1” for long distance and placing a long distance call to anywhere in the United States involved dialing a minimum number of numbers. – only 11. This included “1”, the area code, and the 7 digit number. Customers that wanted to used other long distance carriers had to dial 25 numbers to make a long distance call. These calls required an 800 number be called initially (11 numbers), a 4 number personal identification number (PIN), the area code, and the 7 digit number.

In 1987 a method called Feature Group D was implemented to automatically pass calls to the customers preferred long distance carrier using something called a Preferred Interexchange Carrier (PIC) number.  Customers are required to select a preferred carrier and the preferred carrier information is added to the local switch database the customer is connected to.

Feature Group D also allows a customer to bypass the preferred PIC by dialing a 101XXXX number and use another long distance carrier. These 101XXXX are commonly referred to as dial-around service numbers.

RIP Steve Jobs

“.. almost everything – all external expectations, all pride, all fear of embarrassment or failure - these things just fall away in the face of death, leaving only what is truly important. Remembering that you are going to die is the best way I know to avoid the trap of thinking you have something to lose. You are already naked. There is no reason not to follow your heart.”

Steve Jobs

1955 - 2011
Rest In Peace