The Quest for Quality Service
The goal of all telephone companies is to get fiber-to-the-home for all customers. However, given the cost of replacing the copper infrastructure with fiber it will take years to accomplish this task especially in brownfield construction. Budget constraints force telcos to take a look at their existing copper infrastructure and at what can be done to provide maximum quality bandwidth.
Therefore, for the near (and maybe distant) future, the condition of your copper infrastructure is the key in delivering quality service to your customer. Purchase the best switch that money can buy, reach the customer by fiber, and DSLAM the node for high-speed Internet. Purchase the best head-end equipment for 3-stream video, and offer video games on demand, plus a myriad of other services over paired copper conductors. But, if the copper isn’t up to snuff, it isn’t going to happen.
Let’s begin with a bit of history. When I was a kid on the farm, we didn’t have a telephone. If there was an emergency, one of us would run to the neighbor. The neighbor had a wooden crank phone and the neighbor had to ring up the telephone operator, who in turn would patch the call to its proper destination.
When we got our first telephone, it was a dial phone. I’m sure that the central office switch was some kind of mechanical stepper switch. Telephones have progressed to touch pads for dialing, electronic ringers, cordless, and so on. We also have caller ID, fax machines, modems, plus an innumerable amount of other end-user equipment.
Switches have progressed from panel to stepper to crossbar to digital to the soft switch. We have a plethora of remotes available to provide customer service to, call blocking, conference calling, and countless other features. The only thing that hasn’t changed is tip and ring, the vehicle that provides these services.
The older analog services didn’t require a fine-tuned circuit to provide service. Load coils were necessary for customers beyond 18,000 capacitive feet to guarantee that high frequency and low frequency signals traveled at approximately the same amplitude in approximately the same phase. The human ear would not notice any change in amplitude until the amplitude changed more than 3dB.
Load spacing could be placed within 300 to 400 feet of the acceptable spacing and the service was still fine. Missing or misplaced load coils only affected longer service, and technicians were only dispatched on poorly designed circuits when the customer complained of a howl or a squeal on the line.
Pulse dialing was the norm, and pulse dialing was unaffected by poor circuit design. When touch-pad dialing was introduced in 1962, there were countless complaints of dialing problems. To provide quality service, the tip and ring circuit had to be upgraded. Missing load coils, misplaced load coils, double load coils, too much end section, not enough end section, too much 26-gauge cable — were some of the transmission culprits.
To combat the circuit design problems, every field technician was given a transmission test set and required to test those circuits that didn’t meet the design criteria. Transmission engineers identified and fixed those problems. Technicians found that if the telephone could access the DTMF receiver and the call went through, perhaps to the quiet line termination and the circuit was quiet, transmission testing wasn’t really necessary.
Life was good.
Then along came the fax machine, caller ID, and the modem. The newer end-user equipment required the POTS circuits to meet strict circuit design criteria. If the line tested free of DC type faults but there was still a problem — such as a fax machine not connecting, caller ID not working, or a modem problem — the root cause was marginal or unacceptable circuit design. Field technicians were forced back to transmission testing.
Now we are in a broadband world. xDSL services require exceptional circuit design and many problems are identified and fixed by transmission testing. This is still a must. There are other problems still to be faced, and one of the biggest ongoing challenges is vacant cable pairs.
The same managers that take a field technician to task for moving the customer from the red-green inside station wire to the yellow-black inside station wire when the red-green is in trouble will direct field technicians to do the same thing in a 900-pair cable when a splice is failing due to water rather than proactively fixing the root cause of the problem.
At management’s direction, field technicians restore service by cutting circuits to other cable pairs when DC type faults are encountered rather than fixing them. These circuits still have uncanceled signals (power influence) that will affect adjacent DSL circuits. For example, a tip ground on pair #2 can disturb an ADSL circuit on pair #3.
This is my firm recommendation to all telephone companies that plan on providing bandwidth for any service over paired copper conductors to their customers: Go proactive. Identify, find, and fix all DC type faults, such as shorted, grounded, crossed, and open cable pairs. Pay special attention to bonding and grounding issues. These transmitters of unwanted signals will affect your DSL transport.
As an aside, proactive telephone companies have fewer dispatches and fewer customer complaints. They are the ones who are making money today and are investing in the new services for the future. You take care of your outside plant and it will take care of you.
It’s hard to move to a proactive approach and I’m not unrealistic — it won’t happen overnight even with budget and best intentions. However, if it’s a corporate mandate, you will improve and you will keep your customers and gain new ones. For more ideas on how to build in a proactive approach to your infrastructure, email me at firstname.lastname@example.org or call me at 831.818.3930.