AT&T embarked upon changing out vast areas of their network with a new fiber optic send system to improve upon their aging twisted wire technology called POTS (plain old telephone system) starting about 2007.  The company provided fiber optic hub boxes out from their old block house switch barns and called it U-verse.  The fiber optics trees out from the old switch building into committees called fiber to the neighborhood (FTTN) so as to push forward a much better technology.  They were loosing customers with their old system and needed to instill a significant upgrade.  The theory being that fiber optics offers low signal loss, zero cross talk and huge bandwidth, ideal choice for a robust modern technology improvement.  Problem is they could not afford to provide fiber all the way to your house and business, a huge and vastly expensive undertaking for buried community utilities and also expensive for pole/aerial delivery.  Verizon tried that by putting fiber optics on top of the old twisted wire systems that used poles but had to charge huge amounts of money, like $80 a month for Internet.   That system could not be sustained because the customer was not willing to pay the high cost.  The AT&T method is quite literally, in many ways, short of the Verizon system.  AT&T put fiber out to the street somewhere, hopefully close to your home and business, and then switched over to the old existing copper twisted pair for the final run into your home.   This system is called Fiber To The Cabinet (FTTCab) or fiber to the node (FTTN).  You can spot these devices because the show themselves as two metal cabinets side by side on a side walk close to your home.  One is the fiber box and the one next to it is the POTS box.  They are tied together with an underground U shaped pipe.  This is not ideal for a number of reasons.  First, the last and final leg of the signal delivery is the old twisted copper pair connections or POTS.  These connections had to be renewed by sub contractors because the old system connections were not that reliable.  You might have seen crews of workers opening the old twisted wire boxes and reconnecting the wires.  Second, the twisted pair wire is not as capable as the cable company coax for making a good high quality run into your home.  Cable companies add amplifiers along their coax lines to boost signal strength and maintain bandwidth.  At this moment, AT&T is not adding twisted pair amplifiers into their lines but rely on the closeness of the fiber to cooper change over locations FTTN.  Another issue is that the old existing cooper wire system uses large multiple strand cables that go from box to box in the ground or from pole to pole from which they string out each customer’s signal.  Each box is called a node.  Your home or business can be down from the FTTCab a large number of node connections which imparts added points of electronic resistance loss.

Another problem inherent in the final leg of signal delivery is all the advantages of fiber disappear.  Cross talk, line resistance and decreased bandwidth are significant factors.  The bandwidth problem is handled with a special technology called DSL.  DSL uses much higher send frequencies for digital signals and filters to separate out the high  frequency digital signals from  voice  signals.  In the home you will see two wall connections.  One will be for DSL and the second PHONE.  With the U-verse system you will see a CAT connection labeled U-verse and the other will be for your phone.  The prior DSL system had been replaced with ADSL2+ and VDSL or very high bitrate digital subscriber line.  Both system offers very good up and down digital speeds but the benefits degrade with distance from the fiber change over to POTS wiring.

Another problem for AT&T is the final installation in home or business requires an installation technician to come out, rewire existing connections and test the line.  It is true that cable companies may need to come out to some customers, but that is an option.  The point here is that with cable TV, there is an option for a technician to come out but with U-verse an installation technician is REQUIRED.

AT&T has, at this writing, five levels of Internet service from 24 Mbit/s down to 3 Mbit/s.  If you go into any of their stores you can order any speed you want if you are willing to pay for it, up to 24 Mbit/s bits per second  down speed and up to 3 Mbit/s bits up speed.  Problem is, you must have your house within 1000 feet of the change over box to get the maximum speed.  Our home was 2,900 feet from the box and thus we could only attain Elite service which was second from the bottom.  The installer told us we could only get 12 Mega bit speed down due to our distance from the change over box.  We understand, also, that our TV signal may be affected with a loss of pixels on the screen.

Standing back from this AT&T system and compare it with the cable company, one can see that the cable company has a huge advantage over the AT&T U-verse system for homes that are past a certain distance from the change over box.  Our cable company offers 20 Mega bits down speed and 1Mega bit up speed for ALL homes within their system.  The AT&T offers a variable delivery.  They can NOT offer top level service like the cable companies can to all their customers.

Reference:

• VDSL technology Issues – An Overview:    http://www.analog.com/library/analogdialogue/archives/34-05/vdsl/index.html
• For an under the hood look at fiber optic to cooper implementation: http://wn.com/fiber_to_the_node