BellSouth Adopts Effective DSL Line Qualification Method
By Dennis M. Slattery
Director, Florida Business Customer Services
BellSouth Telecommunications, Inc.
BellSouth has set aggressive goals for broadband service implementation in 2001, with plans to have more than 600,000 ADSL customers in service across the company's nine-state serving area by the end of the year. With slightly over 200,000 subscribers in place at the beginning of the year, and an estimated 40% of the installed plant ready for DSL service without rehabilitation, this DSL service expansion represents a challenge of significant proportions.
Five of the ten largest BellSouth Corporation regional markets are in Florida. Broward County in South Florida expects to add well over 30,000 ADSL circuits by year end—a significant portion of the nearly 175,000 new ADSL circuits targeted for the South Florida region in this period.
Scott Mulcahy, BellSouth Network Vice President for South Florida, initiated a “Best Practice Team” for Special Services/ADSL last year to determine methods and procedures to reduce installation intervals, help meet customer-desired due dates for various digital service offerings, and reduce the duration of service outages. This best practices team was chaired by Vince Rubiera, General Manager -North Broward Division in Fort Lauderdale, Florida.
"We are seeing a 35% growth per year in special services, with data traffic surpassing voice for the first time in the company's history," Rubiera said. "This is a time for an imaginative approach to problem-solving, and for new methods and systems that will improve efficiency. Many cables in South Florida were originally designed to meet our more tolerant voice-grade specifications so it is imperative that any incompatible features be located and redesigned due to their possible impact on the ability of our facilities to carry broadband signals."
It was clear to the Special Services Best Practices Team that without proper equipment, it is very difficult for installers and cable maintenance technicians to dependably qualify pairs for broadband service, and to diagnose and correct line problems. The team identified a need for a simple and effective job aid, to qualify copper cable pairs for broadband service, to give a dependable go/no go indication of broadband service readiness, and to diagnose and clear service-affecting troubles.
After a study of available options, Rubiera's team suggested that the Telco's North Broward Division work closely with Tom Beattie, 3M’s Telecom representative, to develop an application guide and conduct a field trial of the 3M- Model 1332 Far End Device. The 3M FED is a small battery-powered accessory designed to be used with the multi-function 3M Dynatel 965DSP Subscriber Loop Tester, which is already widely deployed in the BellSouth force.
The compact FED is connected to the appropriate pair at the frame, using a “special” adapter cord from Westek Electronics. Next, the device is remotely activated by the Subscriber Loop Analyzer. The FED places an ID tone on tested lines from the CO end so that key line properties can be measured, including insertion loss, slope, loop resistance and resistive balance. Once the system is connected to the line in question, no further effort is required by the C.O. technician.
The field tests were conducted by BellSouth Facility Technician Barry Dawson in the North Broward, East Cable Repair Group under the direction of Area Manager - I&M, Henry Castles. Dawson used the device on every pair he worked with during the trial period, and found that when a pair qualifies with this test procedure, it is truly ready for ADSL and other Broadband Services.
"This was a huge step forward from our earlier methods, where we could never really be sure if a line was data-ready until it was put into service," Dawson said. "Some lines would fail after a brief period, and then we would have to make repeat visits to change out pairs at both ends. A go-back adds delay and substantial cost to service orders.”
"Before employing the new device,” Dawson added, “our primary option was to use analog methods to test for digital readiness. Even if a technician was proficient with available test equipment it was necessary to call in to the C.O. tech for help to strap one pair at a time and walk through the process together. We had no ability to send a tone or to test all the parameters of pair quality, and this work was time-consuming and cumbersome. With the new equipment, one person can now do all of that and much more, including pre-qualifying a line for specific HDSL, ADSL, ISDN or T1 use."
Dawson reports that the new device makes it possible for a field tech to make detailed measurements of pair performance back to the central office without help, except to have a Central Office Frame Technician connect the test gear to the pair in question. "The FED places an ID tone on the tested line, and then the 965DSP can take loss measurements up to 1.2Mhz, and quickly determine slope, loop resistance and resistive balance values from the test point to the central office," he explains.
During the field trial, Dawson was also able to use the equipment to effectively diagnose and reclaim pairs that did not qualify for data service. With these two devices alone he could detect and then locate load coils, bridge taps, wet cable sections or other troubles, following simple steps. He found the equipment combination was useful for point-to-point measurements in the field as well as testing back to the central office.
Based on the success of the best practices study and the North Broward trial, the BellSouth headquarters staff has approved the system for further deployment in the company and it is expected that the devices will be available to central office personnel and field technicians throughout the region.
"Given the challenging objectives for broadband implementation this year, it is imperative that BellSouth installation and cable maintenance crews be provided with effective equipment and trained in its use as quickly as possible," Rubiera said. "In the South Florida region alone there were nearly 700 new field technicians hired by BellSouth in 2000."
More than half of the BellSouth field work force has less than 18 months experience in their current jobs. This situation presents huge equipment and training challenges, and reinforces the need for effective, efficient and easily-used test equipment that gives accurate and repeatable results in the field.
BellSouth Florida managers will have deployed the new test system in the five South Florida Divisions by the end of the first quarter, 2001. It is expected that successful regional implementation will encourage adoption of the line qualification process in other areas of the operating company as test sets and training are made available.
"With a growing demand for internet and e-mail service, the customer is driving our pursuit of for improved installation and service efficiencies," said South Florida Network Vice President Mulcahy. "Our success continues to be based on providing excellent service to all of our customers. Telecommunications consumers are interested in our ability to meet their desired due dates and in how rapidly we can restore service outages so we always welcome new test gear that can help us in meeting these expectations.”
Mulcahy added that, "The new system our employees have researched appears to offer an economical, effective solution to a challenging Telco problem. It will be especially helpful to recently hired field technicians and, in the long run, promises to become a useful tool as the BellSouth team works to accomplish aggressive 2001 ADSL service goals."
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Author's Biography
Dennis M. Slattery is currently the Director of Florida Business Customer Service Centers for BellSouth Telecommunications, Inc., and is located in Ft. Lauderdale, Florida. He has 36 years of Telco industry experience, working for Ohio Bell before joining the BellSouth organization in 1979. Slattery has a broad network operations background, including work as a technician, construction manager, in installation and maintenance, cable repair, digital line carrier, fault location training, and special services.
The BellSouth POTS and Broadband Test Set
The multi-function 3M™ Dynatel™ 965DSP Subscriber Loop Analyzer and an associated Far End Device have been established as the BellSouth telco standard for POTS, wideband and DSL-specific pair analysis based on highly successful field trials in South Florida. Key functions of this combination of test sets for BellSouth include fault location and repair verification for twisted pair and drop cables. The 3M Analyzer and Far End Device handle voltage and current measurements, tone generation from voice to wideband frequencies, full TDR features, fault location, spectrum analysis, and other important tests.
Wideband pair analysis with the self-contained 3M test unit begins with signal and noise measurements, which can be supported by a spectrum analysis capability should excessive noise be encountered. Spectrum analysis covers the critical range of 10 KHz to 1.8 MHz, with a dynamic range of –90dbm to +10 dbm. Other functions make it possible for a user to locate sources of noise..
Operation of the 3M™ Dynatel™ 965DSP is simplified by an internal help menu that guides the user step- step for each operation. Object-oriented software allows for test set upgrades in the future.
The 3M Model 1332 Far End Device (FED) is designed for use with the Subscriber Loop Analyzer, and provides loss measurement up to 1.2Mhz. This accessory saves steps in the field, and eliminates the need to use dual Subscriber Loop Analyzers and two technicians for network testing. It is connected to the appropriate pair at the frame, and remotely activated by the 965DSP. The FED places an ID tone on tested lines so that key values can be measured, including insertion loss, slope, loop resistance and resistive balance. A field technician can also use the device to verify cable sections apart from the central office
The Far End Device is powered by a 9V alkaline battery, and test cord leads are connected to pairs on the frame using a “Special” cable made to BellSouth specifications by Westek Electronics. FED controls consist of a pushbutton on/off switch and an LED power indicator.
