April 28, 2004 Research Triangle Park, NC -- Scientists at MCNC Research & Development Institute (MCNC-RDI) continue to validate the Just-in-Time (JIT) optical networking protocol for ultra-fast provisioning and management of all-optical network connections. The protocol was recently demonstrated for the Federal Communications Commission (FCC) at the Naval Research Laboratory's Center for Computational Science.
"The JIT protocol is a new approach to light path provisioning that could significantly reduce communication delays in the networks," reports Edmond J. Thomas, FCC chief of the Office of Engineering and Technology. "JIT not only has the potential to enhance today's network infrastructure but the technology also could potentially improve efficiency for applications bound by limited resources such as the wireless spectrum. This protocol is yet another example of technological innovation which could result in more efficient use of the radio spectrum and hopefully lead to new and affordable services for the American public," he adds.
Developed jointly by researchers at MCNC-RDI and North Carolina State University, JIT represents a breakthrough in the transmission of high-capacity signals by addressing the frequency, availability, and data rate challenges facing current and emerging bandwidth-intensive applications. JIT signaling reduces latency and increases efficient use of the network. It is being used to create a new optical network service that features fine-grain multiplexing of wavelengths.
Although the JIT protocol and control plane originally targeted application to optical networks, it was designed to be independent of media type. Recent analysis at MCNC-RDI shows that the JIT technology also offers advantages in other types of communication networks, such as wireless and satellite.
"Standards for signaling in optical public networks are evolving and will ultimately lead to connectivity between today's optical networking equipment and the rest of the global telecommunications network," explains John Mazur, principal analyst at Gartner, a market research firm. "Carriers must explore new signaling protocols to provide bandwidth on demand capabilities to both higher layer equipment and to end-users. Minimizing bandwidth provisioning cycles and their expense will go far in improving carriers' profitability as well," he says. "The JIT protocol provides a migration path to tomorrow's optical technological advances in bufferless switched networks, nano-second optical switch configuration times, inexpensive wavelength conversion technology, and fine-grain lambda multiplexing."
Since October 2002, JIT signaling protocols and hardware implementations have been successfully deployed across test-bed networks confirming the viability of ultra-fast provisioning. In January 2004, MCNC-RDI demonstrated the JIT protocol to the FCC by successfully transporting uncompressed digital 1.5-Gbit High Definition Television (HDTV) signals through an all-optical light path. The HDTV transmission required no conversion processing within the network as it remained in the all-optical data plane from source to destination.
Today's standards for provisioning optical connections via carrier networks or through generalized multi-protocol label switching (GMPLS) are not sufficient for bandwidth-intensive applications such as computational steering and visualization steering. In most cases, establishing light paths can take days or minutes, making it difficult to efficiently share wavelengths. The JIT protocol provides a mechanism to set-up and release connections at the millisecond to microsecond timeframes (depending on switch configuration times) allowing fine-grain multiplexing of the data plane. This enables on-demand, application-initiated provisioning of bandwidth.
"JIT provides a mechanism to establish end-to-end optical connections in microseconds, where data can be as small as packets or as large as long-lived light paths," notes Dan Stevenson, vice president of MCNC-RDI's Advanced Network Research Division. "Multi-wavelength, reconfigurable optical networks offer greater capabilities than current transport SONET and IP router technologies when applications need large data units to achieve and maintain sustained data rates as high as 10 Gbits/sec."
The JIT protocol combines the valuable features of packet and circuit switched services and provides out-of-band control signal processing to maximize set up time and optical switch bandwidth efficiency. Signal messages travel in advance of the data they are describing and undergo electro-optical conversion at each intermediate node. Switching elements inside the switches are configured for the incoming data (a tell-and-go approach), thus minimizing network latency by eliminating round-trip waiting time. In JIT, data remains transparent to the intermediate network, which means data channels being transmitted on individual wavelengths can convey analog (e.g. radar) and digital traffic in any format, data rate or modulation scheme.
JIT protocol highlights:
• Out-of-band signaling on a single channel -- Signaling channel undergoes electro-optical conversions at each node to make signaling information available to intermediate switches.
• Data transparency -- Data is transparent to the intermediate network entities; i.e., no electro-optical conversion takes place at intermediate nodes and no assumptions are made about the data rate or signal modulation methods.
• Network intelligence at the edge -- Most "intelligent" services are supported only at edge switches; core switches are kept simple.
• Signaling protocol implemented in hardware -- To avoid bottlenecks and to achieve wire speed operations, the signaling protocol is implemented in hardware.
• No global time synchronization -- Time synchronization between nodes are not assumed.