Another potential broadband solution, broadband over power line (BPL), is rearing its ugly head again. This technique of modulating broadband data on ac power lines isn’t new. Implementing a system that works fast enough and doesn’t interfere with radio services in the spectrum used by the modulation (orthogonal frequency- division multiplexing, or OFDM, in the 2- to 80-MHz range typically) has taken several years.
So, the BPL industry learned a great deal during the last few years and wants to give it another try. Its representatives claim to have solved the interference problem with new and better mitigation methods. They also say data rates are higher. A new company called International Broadband Electric Communications Inc., along with IBM’s considerable help, is trying to get back into the business, especially to serve rural areas.
The power lines are already there, so all that’s needed is the broadband technology and the related service. New repeater technology with frequency agility control to reduce interference may just be what makes this work.
ETHERNET DOMINATES • In 2008, Ethernet celebrated its 35th year of continuous service. It’s survived many challenges and competitors and has grown and improved to become the one go-to network. But more is on the way. In addition to seeing Ethernet on backplanes, watch out for more localarea- network (LAN) as well as newer metro-area-network (MAN) and widearea- network (WAN) apps.
The adoption of 10 Gigabit Ethernet (10GE) continues at a rapid pace. Lower- cost optical transceivers are helping, and many data centers are adopting the shorter-range 10GE copper options that put those data rates on CAT6a cables up to 100 m long.
Work on higher-speed versions of Ethernet also continues, showing promise for both 40- and 100-Gbit/s versions in the near future. The Road to 100G Alliance recently merged with the Ethernet Alliance to form a stronger organization dedicated to achieving those high-rate versions.
According to Bill Weisinger, the 100G Alliance chairman, the organization’s goal is “to establish a comprehensive ecosystem of suppliers and users to accelerate the adoption and ongoing development of high-performance networking solutions.” The combined Alliances are expected to speed the development of new 802.3 standards for 40/100-Gbit/s technology.
Two major developments helped pave the way to 40/100 Gbits/s. First, techniques for chromatic and polarization mode dispersion have been developed, proven, and adopted, overcoming the primary roadblock to longdistance fiber connections at 40/100 Gbits/s. Second, the Optical Internetworking Foundation (OIF) adopted dual polarization-quadrature phaseshift keying (DP-QPSK) as the modulation method of choice for 100-Gbit/s systems. Some 40-Gbit/s systems plan to use that technique, too.
Ovum, an advisory and consulting services firm, indicated that 40-Gbit/s products and services are moving into the generalized deployment phase as the demand grows for consumer video. The biggest application is router-torouter connections. Adoptions will definitely increase as the industry works to reduce the cost of 40-Gbit/s equipment. Sprint just announced its successful Internet Protocol (IP) 40-Gbit/s link from New York to Sweden, a 9000-km distance, using dense wavelength-division multiplexing (DWDM) over a submarine fiber cable.
Another major ongoing development program is carrier Ethernet, a version of Ethernet that better fits the needs of carriers and service providers who must move huge amounts of data reliably with minimal latency and exceptional quality of service (QoS). Carrier Ethernet isn’t a version of the IEEE 802.3 standard, but was developed and supported by the Metro Ethernet Forum and the ITU.
These organizations are working on a standard that will make Ethernet a key transport network technology instead of its designation as a LAN-only technology. Carrier Ethernet will allow network providers to offer expanded services of pure IP data at reasonable rates. One promising target is cellular backhaul for 3G and 4G networks.
Other Ethernet developments include the growth of iSCSI for storage-area networks (SANs), Fibre Channel over Ethernet (FCoE) for SANs, and backplane Ethernet. However, Ethernet still competes with InfiniBand in connections to servers, mainframes, and supercomputers.
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