I can't believe Ascend is not mentioned in this article???? I have asked the editor to ask the writer why Ascend was not mentioned in this informative article.
Focus on Communications
Converging telecom demands fuel broadband
networking
By Lili Goleniewski
Advances in telecommunications have been nothing short of fantastic -- in less than ten years we have gone from discussions
of integrating voice, data and video communications to visions of networks capable of transporting the full range of human
senses. In just the last five years, the level of data traffic has grown to equal that of voice, and video communications has been
consistently demonstrating growth rates of 50% per year.
And even then we are only at the beginning of a new era of communications -- one characterized by
convergence -- the convergence of networks (witness the @Home topology), the convergence of devices (like
Microsoft's WebTV or Philips P200 Internet Home Phone), the convergence of applications (the edutainment
value of DK encyclopedias), and ultimately, the convergence of man and machine. The next five to ten years will
bring about a massive convergence of telecommunications and computing, placing unprecedented demands on
telecommunications infrastructures worldwide.
New networks generation
In response, we have begun our transition to the broadband era of communications, a major transformation of not only public
switched telephone networks, but also the Internet, cable TV architectures, and wireless networks. Broadband networking is
the generation of infrastructure designed for life in the new millennium. This new generation of networks will support a wide
range of end-user applications with varying requirements for bandwidth, throughput, delay, variation in delay, reconfiguration
intervals, and unique vertical services.
To satisfy the requirements of future services -- including networked education, distance learning, telemedicine, electronic
commerce, networked games and gaming, and electronic democracy -- telecommunications networks are undergoing
significant functional changes enabled by advances in transmission, switching, and signaling technology.
This revolutionary transition includes the deployment of several key technologies: SONET/SDH, frame relay, ATM, intelligent
networks, broadband local loop, and wireless alternatives.
Fiber-based SONET/SDH infrastructures are replacing the existing PDH hierarchy (T/E/J Carrier networks) and can support
transmission rates measured in Gbps, with Tbps projected by the year 2000. Among the key equipment providers we can
expect to see at Fall are Alcatel Network Systems, Fujitsu America, Lucent Technologies, NEC America, Philips, Rockwell
International, Siemens.
Due to the explosive growth of applications (which include high-speed data, image processing, and networked interactive
multimedia), service providers are seeking to increase the capacity of their existing fiber optic networks. According to
Bellcore estimates, by the year 2000, bandwidth demand will be 500% greater than it is today.
Enter Dense Wavelength Division Multiplexing -- a combination of optical multiplexers and optical amplifiers that allow
multiple optical signals to be transported as a group, over a single fiber. Wavelength division multiplexers offering 20- and
even 40Gbps are now available, 80Gbps are expected in a year, and 1Tbps projected by 2000. Wavelength division
multiplexers (WDMs) now shipping support from four to 32 wavelengths at 2.4Gbps per color. Nortel is trialing an
8-wavelength system based on OC-192 (9.6 Gbps) elements, and the ITU is standardizing 96-color WDM.
ATM switching technologies, which operate at SONET/SDH speeds and provide for Quality of Service definitions, are being
deployed in all the major infrastructures, PSTN, Internet, cable TV, and wireless networks. Key manufacturers include
3Com, Bay Networks, Cisco Systems, Digital Equipment, Fujitsu, Hitachi, Hughes LAN Systems, IBM, Lucent
Technologies, NEC, Nortel, Siemens, and Standard Microsystems. Virtually every telecommunications carrier and network
operator around the world has begun the deployment of ATM services.
Frame relay access to ATM backbones will also play an increasingly important role, enabling cost-effective data networking
solutions. Key providers of carrier switch products include Lucent Technologies, Cisco, Hughes Network Systems, NEC,
and Siemens. Internetwork vendors offering frame relay products include Bay Networks, Cisco Systems, 3Com, and
Motorola ISG. Voice-over-frame relay products are also available.
Intelligent network architectures will be critical to allowing rapid service rollout and provisioning, while also providing for
customer-based network configuration. AIN (Advanced Intelligent Network) platforms operate as servers and are being
developed by the switch/carrier providers, as well as the large computer manufacturers, including HP, NCR, Nortel, and
Siemens. A lower-cost alternative is programmable switches.
Another major effort underway is the modernization of the local loop, providing broadband access. One approach taken by a
large variety of telcos is the introduction of high-speed digital subscriber lines, a variety of techniques affectionately grouped
under the heading xDSLs. These techniques bring new life to the twisted copper pair running into homes and businesses
worldwide. One of these, ADSL (Asymmetrical Digital Subscriber Line), promises transmission rates of up to 6-8Mbps in
the downstream direction, and up to 640kbps bidirectionally. Chip sets containing ADSL transmission and MPEG digital
compression circuits are being produced by Motorola, Lucent, and Alcatel. Trials are being run at 20 telephone companies.
Cable modems up to 30Mbps
Another approach to broadband local access is the use of cable modems. Cable modems can also afford increased
downstream transmission rates, with a potential of up to 30Mbps, albeit shared among the number of households served by
the local node. Cable modem manufacturers include Motorola and HP. Along with the cable TV operators, hybrid fiber coax
architectures are also supported by Microsoft/TCI.
Finally, developments in wireless networking are finding application in all telecommunications domains, including PANs,
LANs, MANs, WANs, and GANs, with increasing emphasis on wireless data communications. Motorola's Iridium is just
one of the LEO (low earth orbiting) satellite networks that promise to provide end-to-end wireless alternatives to traditional
wireline based PSTNs.
Telecommunications is an exciting industry, a converging market, a source of competitive power, and the most essential
infrastructure of the knowledge-based economy. Today, no IT solution can be developed without appropriate knowledge
and consideration of communications infrastructures. For this reason, COMDEX introduces EXPO COMM -- it is your
opportunity to learn about technology fundamentals and recent developments in Communications: Infrastructure Solutions for
the Knowledge Age.
Jeff |
