Electronic Design
We Haven’t Cut The Cords Yet  In Communications Technology

We Haven’t Cut The Cords Yet In Communications Technology

The communications industry is predictable—mostly. Most communications technologies are defined by their standards and boxed in by the regulations of the Federal Communications Commission (FCC). Also, the technologies we use the most are on a roadmap that follows developments in the semiconductor industry.

The unpredictability comes from the timing inolved in reaching these milestones, the industry’s economic conditions, and the innovative breakthroughs that occasionally come along.

And wireless hasn’t eclipsed wired technologies yet. The communications infrastructure continues to advance alongside major wireless developments. Optical fiber leads the way, but copper continues to hang on because it’s still the cheapest way to connect computers and other communications gear.

The 40- and 100-Gbit/s Ethernet standard 802.3ba was approved in June of 2010, and progress is underway in implementing new and upgraded systems. Yet there has been minimal adoption because of the limited optical hardware available and the high cost.

The standard provides for the transmission of standard Ethernet media access controller (MAC) packets over a variety of 40- and 100-Gbit/s physical-layer (PHY) media including a backplane, a 40-Gbit/s copper cable, and a variety of optical media using four or 10 wavelengths via coarse wavelength division multiplexing (CWDM).

A more noticeable movement has been in the adoption of 10 Gigabit Ethernet (10GE) now that plenty of equipment is available and prices are moderating as competition builds. 10GE systems are showing up in data centers and other aggregation points for the millions of 1GE ports out there (see “Carrier Networking Technology Takes Over The Data Center”). That trend will surely continue, and that, in turn, will create the demand for more 40/100-Gbit/s equipment.

Another clear trend is the rise of 10GBASE-T copper connections. With the latest chips, reasonable power consumption, and the range extended to 100 meters, 10GE Ethernet over CAT5e/CAT6 cable is finally being adopted, first in data centers and soon in commercial switches, network interface cards (NICs), and other products.

Local-area network (LAN) on motherboard (LOM) with 10GE is also expected as chip vendors move up to the next-generation PHY and MAC using 40-nm technology and adopting Energy Efficient Ethernet (EEE) technology. PLX Technology recently acquired 10GBASE-T chip vendor Teranetics and projects that over the coming years this copper solution will take more of the 10GE market share (Fig. 1) as prices drop and power consumption continues to improve.

The big news with Ethernet is EEE. The IEEE’s latest standard, 802.3az, provides a way to greatly reduce power consumption in Ethernet networks. The final standard was ratified on September 30 last year and is now available in chips from Broadcom and Vitesse.

EEE offers mechanisms within the PHY and MAC standards to provide a way to reduce energy consumption. It does this by communicating state and control information through the network connections that allow the equipment to disable or enable parts of the system as needed.

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Most Ethernet connections go unused until they are needed, at which time they transmit and receive data in very short bursts. Power is wasted continuously. The new standards provide for a low-power idle (LPI) state where power-hungry circuits that aren’t needed are shut down until data is received or transmitted.

With billions of Ethernet connections installed worldwide, power consumption is enormous with the real impact being felt in large data centers. If EEE is widely implemented in most existing Ethernet ports, the annual savings could reach the terawatt range.

The other big Ethernet news is the continued growth of Carrier Ethernet. Dveloped and certified by the Metro Ethernet Forum (MEF), this new version of Ethernet provides dedicated Ethernet bandwidth and services to businesses, academia, and other organizations that expect and demand a certain quality of service (QoS) when needed.

Software and hardware provide an alternative to the traditional dedicated connections like Sonet/SDH and guarantee a specific level of performance and service that the telecom carriers demand. Carrier Ethernet is much less expensive than Sonet/SDH and scales with standard Ethernet speeds. It is fully packet-based and can be delivered over any Ethernet network, such as LANs, metro-area networks (MANs), and wide-area networks (WANs).

Carrier Ethernet is being used to implement the faster mobile wireless backhaul connections and other links that carry extensive Internet traffic, especially video streaming, video on demand (VOD), Internet Protocol television (IPTV), and gaming. Infonetics Research reported that the Carrier Ethernet router and switch market grew 21% per year from the third quarter of 2009 to the third quarter of 2010. Look for that trend to grow along with Internet traffic.

Internet Address Crisis
We’re running out of Internet addresses. The generally accepted assessment indicates complete exhaustion by September 2011. These addresses are part of the IP assigned to every computer and other Internet-connected device. They are written in a dotted decimal format—for example,

Internet Protocol version 4 (IPv4) devotes 32 bits each for source and destination addresses. That means 232 or just over 4 billion possible addresses. Who would have thought back in 1981 when this protocol was finalized that there would be more than 4 billion possible devices ready to use the Internet?

Apparently all the available addresses have been assigned, thanks to rapidly expanding broadband connections, smart phones, and other deployments. Now what do we do?

The answer is IPv6. Finalized in 1999 and already deployed to some extent, Version 6 of the Internet Protocol provides for a 128-bit address or 2128 potential addresses. That’s a number too large to contemplate, more than 340 trillion trillion trillion, but it should be enough to cover us for the near future.

That quantity will ensure that we will have an address for each of our multiple computers, phones, and other devices. It will provide for every appliance, toy, machine-to-machine (M2M) device, and anything else you can think of.

The addresses will be expressed in a dotted hex format as eight groups of four hexadecimal numbers. IPv6 will also provide for authentication and multicasting, which is the ability of IP to move fast video and audio over the Internet from a single source to multiple destinations—a major improvement for the future of entertainment.

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All software that uses the Internet will need to be updated to handle IPv6. Many large organizations like Comcast, Google, Verizon, YouTube, and Netflix already deploy IPv6. Internet growth depends on quickly adopting IPv6. Just keep in mind that IPv6 is not backward compatible with IPv4, though.

Instead, it will be necessary for servers and other devices to run, maintain, and support both IPv4 and IPv6 simultaneously (via dual stacks). Otherwise, the transition from IPv4 to IPv6 could be via network address translation from v6 to v4 (NAT64). Alternately, there is a way to permit the tunneling of IPv6 packets over an IPv4 network.

In any case, the key is to start the transition now since the conversion is not an insignificant project. Just think of all the routers, firewalls, servers, and other hardware that needs to be updated. All Internet-related software also needs attention, including operating systems, network management tools, and applications software.

All federal government agencies are mandated to have IPv6 connections in any public access service by 2012. The government is scrambling, as are most large businesses, to fix this problem. No one is expecting a Y2K type of response, but the conversion is still nevertheless a massive project.

New optical components are now available to implement 100-Gbit/s connections. The first short-reach systems using InfiniBand and Ethernet are being introduced into high-performance computing (HPC) systems and data centers. One preferred arrangement is four 25-Gbit/s parallel paths, either four wavelengths on one fiber or four fibers.

Luxtera’s CMOS-based Silicon Photonics platform (Fig. 2) provides 25-Gbit/s transmitters that use a single always-on laser with waveguide level modulation and receivers with on-chip photodetectors that make this technology practical and even cost effective. Luxtera’s technology is so good that some consider it truly disruptive.

“A technology is considered disruptive if it is so much better than current practice that it is poised to displace the incumbent technology and become the standard practice for future technologies,” said John Shalf, advanced technologies group leader at Lawrence Berkeley National Laboratory, at November’s Supercomputing 2010 event in New Orleans. So with 100 Gbits/s a “real” technology, watch for increased adoption.

Another optical technology gaining ground is the optical transport network (OTN), which is gradually being used to upgrade our fiber backbone and Internet infrastructure. OTN offers the packet-based protocols and optical technologies that upgrade the networks to the magical 100-Gbit/s data speed level. And it can do this on a single fiber over a long range, unlike the multi-fiber or multi-wavelength methods used in 40/100-Gbit/s Ethernet thanks to some new modulation methods and special optical cable and transceivers.

OTN is considered a “digital wrapper,” as it was designed to transport almost any other protocol including the ornery Sonet/SDH and all versions of Ethernet. Sonet/SDH has been the long-haul and metro optical solution for years, but its operation is not defined at speeds beyond 40 Gbits/s (actually 39.813 Gbits/s). Sonet/SDH won’t go away soon, but it will gradually be replaced with OTN. In the meantime, OTN will carry Sonet/SDH along with Ethernet.

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Broadband comprises high-speed fiber, cable, DSL, and wireless connections to homes. As of the end of 2009 (2010 data not complete), 64% of U.S. homes had such a connection, compared to 51% in 2007. 2010 data will show additional growth, although it may be slowing.

Most broadband homes are Caucasian and Asian, while the homes of African Americans and Hispanics show much less connectivity. Rural areas are also still underserved. The National Broadband Plan announced by President Obama last June promises broadband for everyone, but little action has taken place.

Most related activities involve companies figuring out ways to bring broadband cheaply to rural areas, and the Federal Communications Commission (FCC) and National Telecommunication and Information Agency (NITA) are trying to find that 500 MHz of new spectrum for broadband wireless promised in that National Broadband Plan (see “Net Neutrality Remains A Possibility”). Overall, global broadband connections are growing, as iSuppli recently reported. The primary source of this growth is the insatiable demand from Chinese consumers for fast Internet connectivity.

An interesting counter-trend is the decrease in the number of cable TV subscribers. Many homes are dropping cable service and/or premium channels not only because of the continuing economic depression but also because of the growing number of video streams from broadband Internet connections.

Video streaming from Hulu and Netflix is growing like crazy, as are the other alternative ways to get video online. You can get video on Microsoft’s Xbox as well as via Apple’s TV box. And, services like Ivi and FilmOn stream over-the-air TV, possibly in violation of existing laws, so say the cable companies. With HDTV now available over-the-air, many homes are opting for an antenna to get local stations and supplementing it with Internet video.

While cable connections declined overall, most of the decrease was outside the major markets, where some small growth was observed. This decline could develop into a major trend as the number of video options increases and as the different types of broadband connections become faster. One estimate says that video is now 43% of all Internet traffic, and that percentage is growing. This growth will quickly push the need for 30- to 50-Mbit/s data rates to homes for adequate service.

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