Looking to simplify ADSL-modem access connections, Conexant Systems Inc. has introduced a version of its AccessRunner family of chipsets that provides universal serial bus (USB) support.
The aim is to enable a generation of modems that plug directly into a PC's USB port, eliminating the need to open the host system to install adapter cards such as Ethernet cards, which are generally required with non-USB ADSL modems, said Jay Gottlieb, product manager at Conexant, Newport Beach, Calif.
"We clearly believe that USB is growing and replacing the traditional Ethernet-terminated boxes," he said. "For ease of use, USB is certainly a more powerful and easier method of connecting peripherals."
Conexant's USB-ADSL modem chipset has already received commitments from several customers, including Accton Technology, BeWAN Systems, Digicom Systems, Mac System, Olitec, and Wong's Technology. The modem contains the same ADSL data pump, analog front end, and line driver found in the company's existing ADSL chipsets, but replaces the PCI interface with a USB interface.
"USB is an external box, so to connect it to a PC or laptop is just one simple cable connection," Gottlieb said. "There's no power supply needed, and there's no additional card required for the PC. Installation is really trivial, and USB is definitely becoming the most proliferated way to connect peripherals to the PC."
The USB-ADSL chipset supports full-rate ANSI T1.413 Issue 2, ITU G.dmt, and ITU G.lite specifications. Conexant is also considering adding V.90 capability.
The AccessRunner architecture uses the host PC to perform ATM protocol functions in software. ATM protocol support is achieved through a software-based ATM segmentation-and-reassembly solution that implements the ATM adaptation layer over ADSL. WAN-mode support is provided though industry-standard point-to-point protocol, while LAN-mode functions are supported in compliance with the industry-standard RFC1483 specification. The chipset includes a discrete multitone (DMT)-based data pump.
Although cable modems are currently out-shipping DSL-based modems for broadband-access services, Allied Business Intelligence Inc. (ABI) contends DSL will soon overtake cable in volume shipments.
At the end of 1999, cable Internet service boasted 2.1 million U.S. subscribers, while DSL had only 500,000, according to ABI, Oyster Bay, N.Y. In this year's first quarter, however, some DSL providers were seeing 50% to 60% increases in subscription rates. DSL demand should continue with comparable increases, but local exchange carriers can't deploy the service fast enough, said ABI analyst Joshua Wise.
"Some providers are already experiencing significant backlogs because they can't train technicians fast enough, but this should be resolved by the end of the year, ... and waiting lists will shrink and the DSL horror stories will become less common," Wise said.
High-speed Internet access is expected to increase from 2.3 million U.S. subscribers in 1999 to 42 million in 2005, a 162% compound annual growth rate, while worldwide demand will grow from 5 million subscribers in 1999 to 91 million in 2005, a 160% CAGR. "USB support will ease the provisioning of ADSL lines for service providers, which not only increases consumer satisfaction but also facilitates servicing more ADSL subscribers," said Nick Burd, Conexant's director of ADSL products.
This notion is shared by major modem-chipset suppliers such as Alcatel Microelectronics and GlobeSpan Inc., which also have introduced USB-based ADSL chipsets.
GlobeSpan, Red Bank, N.J., unveiled a USB-ADSL chipset in January that is now shipping in volume, said Nizar Azzam, CPE product-line manager. "USB is the next logical solution for external residential devices, while Ethernet-based solutions will continue to be used by businesses," Azzam said. "USB is coming on as we speak, and I think it'll be the volume leader by early next year."
GlobeSpan's USB-ADSL solution is based on its Titanium chipset and supports all major ADSL standards, Azzam noted.
Alcatel, based in Brussels, Belgium, entered the USB arena in June by introducing a two-chip ADSL chipset based on its DynaMITe architecture. The chipset is slated to enter production in the third quarter.
Conexant's USB-ADSL chipset is now available. The ADSL-DMT data pump and USB controller are housed in a 176-pin TQFP, and the AFE and line driver come in a 32-pin TQFP. The chipset is $45 in 10,000s.