DSL

G.SHDSL: New and Improved DSL

Hold onto your modem, folks. DSL is about to be replaced by—DSL? Call it the new and improved version or DSL on steroids, but whatever you call it, G.SHDSL has arrived and will soon take over the business broadband market.

by Jim Thompson [June 19, 2001]

Enter G.SHDSL, a symmetric, multi-rate DSL combining the best of SDSL and HDSL2, it's aimed at users of DSL for voice, data and Internet access services. Beside being faster and stretching longer distances, G.SHDSL carries an international pedigree. It's a global standard (G.91.2) developed by the International Telecommunications Union's (ITU) Telecommunications Standards Sector based in Geneva. By contrast, SDSL, the current DSL service of choice for business applications, is hardly recognized outside North America.

This is not to say that SDSL has not been a good interim solution. It has been effective in providing symmetrical, high-speed access, but only at the cost of serious challenges for equipment providers. Without a true standard for design, multi-vendor SDSL deployments can be difficult and tricky.

Speed and distance are other factors that strengthen G.SHDSL. The new standard delivers up to 2.3 Mbps per second—compared to 2.0 Mbps for SDSL. It can also be deployed nearly twice as far from the central office (CO) than SDSL, which is limited to a maximum distance of 18,000 feet.

Laurie Gonzalez, Marketing Director for the DSL Forum, said vendors providing G.SHDSL are incorporating it into their equipment as an option.

"This means the equipment supports the standard. There will be a heck of a lot of bandwidth—more than a T1—and G.SHDSL will be cheaper than T1, and it supports video conferencing," Gonzalez said.

Growing interest
Although it's still new, G.SHDSL is already generating a great deal of interest. Paradyne Networks recently introduced the 9788 SHDSL FrameSaver DSL System, a service-level-managed frame-relay-over-DSL (FroDSL) system that supports the G.SHDSL standard. The system extends Asynchronous Transfer Mode (ATM) to the customer location where it is then converted to frame relay.

According to Paradyne, the "new FrameSaver 9788 DSL CSU/DSU and router operate with Paradyne's multiservices Hotwire GrandDSLAM (DSL access multiplexer) as well as any other vendor's DSLAM that is compatible with the new ITU-T G.991.1 standard."

It also allows for DSL, DDS, T1/E1 and T3/E3 circuits to be mixed on the same customer network so service providers can partner with the most cost-efficient access providers.

The SHDSL FrameSaver DSL endpoints are scheduled to be available in July, prices start at US$995.

G.SHDSL routers
Cisco Systems has also announced that it's adding G.SHDSL capabilities to its CPE routers. The routers are part of an end-to-end solution with G.SHDSL line cards for the Cisco 6000 IP DSL Switch family.

"Cisco G.SHDSL business-class solutions enable our service provider customers to increase their profitability on DSL services by better addressing the largely untapped market of small and medium business that are clamoring for cost-effective broadband connections," said Enzo Signore, Director of Marketing for the Cisco DSL business unit.

Signore added that G.SHDSL offers ISPs the potential for increased profits through managed data services, firewall security, VPNs, voice over IP (VoIP) and distance learning.

The Cisco solution has already been adopted by a number of ISPs, including U.S. based NTELOS, Intraconnect of Greece and BBned of the Netherlands.

Paris-based Alcatel joined the party and debuted a G.SHDSL board that allows telcos using Alcatel equipment to offer symmetric service for little more than the cost of ADSL services.

In the coming months, expect to see more equipment manufacturers and ISPs announce G.SHDSL offerings.

Everett Brooks, DSL Forum SHDSL working group chairman, said over time, SHDSL offers service providers a very cost-effective means of deploying symmetrical DSL services.

"It's no longer just a North American standard," Brooks said. "It's truly a global standard now. As a result, you've got the worldwide market driving the price down."

— End