|
Multiterabit networks
The explosive demand for bandwidth for data networking applications
continues to drive photonics technology toward ever increasing
capacity in the backbone fiber network and toward flexible optical
networking. Already commercial Tb/s (per fiber) transmission systems
have been announced, and it can be expected that in the next several
years, we will begin to be limited by the 50 THz transmission
bandwidth of silca optical fiber. Efficient bandwidth utilization will
be one of the challenges of photonics research. Since the
communication will be dominated by data, we can expect the network of
the future to consist of multiterabit packet switches to aggregate
traffic at the edge of the network and cross connects with wavelength
granularity and tens of terabits throughout the core.
The infrastructure required to govern Internet traffic volume, which
doubles every six months, consists of two complementary elements: fast
point-to-point links and high-capacity switches and routers. Dense
wavelength division multiplexing (DWDM) technology, which permits
transmission of several wave-lengths over the same optical media, will
enable optical point-to-point links to achieve an estimated 10
terabits per second by 2008. However, the rapid growth of Internet
traffic coupled with the avail-ability of fast optical links threatens
to cause a bottleneck at the switches and routers.
Multiterabit packet-switched networks will require high-performance
scheduling algorithms and architectures. With port densities and data
rates growing at an unprecedented rate, future prioritized scheduling
schemes will be necessary to pragmatically scale toward multiterabit
capacities. Further, support of strict QoS requirements for the
diverse traffic loads characterizing emerging multimedia Internet
traffic will increase. Continuous improvements in VLSI and optical
technologies will stimulate innovative solutions to the intricate
packet-scheduling task.
|