DSL hops the DLC hurdle: BellSouth makes the most of its little green boxes

When it comes to digital loop carriers, BellSouth takes the cake. With about 36,000 DLCs in its network, BellSouth probably has more little green boxes in its network than any other RBOC. Rather than consider DLCs a hindrance to its DSL deployment, the RBOC is working with vendors to extend its DSL reach.

BellSouth serves 38% of its customers from DLCs, said Laurie Falconer, DSL analyst for TeleChoice, referring to statistics provided by Telcordia Technologies. The number reaches 70% in some areas, she added. Bell Atlantic serves 40% of its customers from DLCs, while Nynex serves 28%. Among all carriers, DLCs account for two-thirds of all new lines provisioned between 1993 and 1998. But when it comes to providing DSL services, "many [incumbent local exchange carriers] and carriers have not addressed the DSL issue because there's not a lot of equipment available," Falconer said.

Alcatel, which supplies equipment to BellSouth, is on top of the game. Using Alcatel's DLC Mini-RAM, a mini DSL access multiplexer (DSLAM) that adds asymmetrical DSL (ADSL) electronics to the DLC, BellSouth can extend broadband services to customers more than 18,000 feet from the central office (CO). Each Mini-RAM supports eight DSL subscribers.

Alcatel has a firm hold on the mini-DSLAM market when it comes to supporting ADSL, and it has a strong share of the DLC market. A line card that eliminates the need for a mini DSLAM at the DLC may boost its share even more. The new card will support two ADSLs, two POTS lines and an integrated splitter, said Paul Segre, vice president and general manager of wireline access at Alcatel. A card with four ADSLs and four POTS lines plus the integrated splitter is under development.

BellSouth worked with Alcatel to equip the Mini-RAM with three critical attributes, said Jay Fausch, senior director of marketing and business development for the DSL business unit of Alcatel. "Since the beginning of time with ADSL, we were looking for ways to extend the ADSL reach," he said. The solution had to operate in both the CO and the DLC, and it had to comply with network equipment building standards. Temperature and power levels in the DLC also were issues.

The main issue when providing DSL services from a DLC is real estate, said Fritz McCormick, an analyst for The Yankee Group. Because space is limited, DSL equipment must take up as little room as possible while also adding as many customers as possible.

Recently, BellSouth began a trial with Pulsecom's WavePacer RAM-1100, which can fit vertically, if necessary, into tight cabinets. It is supplier-agnostic and can be mounted in any DLC. In addition to being thin, the RAM-1100 can talk to any ATM network element, which is important because when traffic comes back into the CO, there are many options on how to take traffic onto ATM, said Sassan Babaie, vice president of sales and marketing for Pulsecom.

The trial with BellSouth will help Pulsecom fine-tune its equipment to ensure that other carriers can use it. "BellSouth is well-known for its DLCs. Their feedback would help any telco," Babaie said.

BellSouth began deploying ADSL services in five geographical areas this year, including Atlanta; Charlotte, N.C.; New Orleans; and Jacksonville and southern Florida. BellSouth plans to extend ADSL services to its top 30 metro areas next year. The carrier has become a pioneer in providing ADSL from DLCs, Falconer said. "This is probably the first we've seen of true ADSL."