40G keeps up with smartphones

If we've learned anything about the evolution of technology, we know the mantra of 'smaller, cheaper, faster" holds true. Whichever brand of smartphone you have, it will have voice and data capabilities, Wi-Fi, Bluetooth and GPS radios, not to mention more processing power than the systems that put a man on the moon. All this for around $200, albeit with a contract (worth $1000s) to a carrier that will supply service and allow you to communicate and stay in sync with your world from the palm of your hand.

Whether you love them or hate them, smartphone usage is increasing even more than expected. According to a recent IDC announcement, by the end of 2010, 269.6 million devices will have been shipped in compared to a mere 173.5 million in 2009. This is a 55.4% year over year increase, and 10% higher than IDC's previous forecast. The growth will continue in 2011 with an outlook close to a 25% increase. Hardly surprising, this is having a corresponding and ongoing increase in mobile data traffic.

Cisco keeps a close eye on network traffic and produces regular updates to their Visual Networking Index (VNI) Global Mobile Data Traffic Forecast, part of the comprehensive Cisco VNI Forecast. The figures are astounding and you can learn new names for numbers with lots of zeros. For example, did you know that, "Annual global IP traffic will exceed three-quarters of a zettabyte (767 exabytes) in four years?" An exabyte = 1 million terabytes or 250 million DVDs. 

According to the latest update from Cisco, "Mobile data traffic will grow at a compound annual growth rate (CAGR) of 108 percent between 2009 and 2014, reaching 3.6 exabytes per month by 2014." To put this in perspective, Cisco tells us that 5 exabytes would be enough room to transcribe all the words ever spoken!

The necessary growth in network capacity, fueled not only by the devices themselves but the applications and services that support them, is tremendous. In order to keep pace with the forecasted capacities and bandwidth requirements, the networks and technologies on which the infrastructure is built are rapidly evolving. Driven by the increasing demand for bandwidth at the handset, network interconnects must increase accordingly and therefore so must the internal communication capabilities of each of the elements responsible for providing service.

AdvancedTCA-based platforms have been broadly adopted across the infrastructure. Utilizing switched backplane technologies, many of these platforms already support 10G internal transmission speeds. The next speed-boost is close at hand as later this year PICMG (PCI Industrial Computer Manufacturers Group), the industry consortia who develop the xTCA suite of standards, is due to ratify a new revision that will take AdvancedTCA backplanes to 40G.

The Network Evolves - LTE

It seems that there will soon be an "app" for everything or anything, and with mobile data usage increasing rapidly, network architects needed a solution - and the solution is 3GPP's LTE or Long Term Evolution. LTE was devised along with the associated all-IP Evolved Packet Core (EPC) to manage the mobile access network.

LTE is the Radio Access Network (RAN) or E-UTRAN to be specific with end user device connections supported by eNodeBs. The EPC has literally evolved from the legacy core network and has three primary subcomponent entities:

• The PDN GW (Packet Data Network Gateway) manages the connectivity from user devices to external packet data networks
• The SGW (Serving Gateway) is essentially a router for user data packets
• The MME (Mobility Management Entity) controls the LTE access-network; it is, amongst other things, responsible for authentication, mobility, interconnectivity with legacy access networks and lawful intercept

The EPC is on a rapid growth path and forecasts suggest it will be worth nearly $2 billion by 2012. As the main connection point for all mobile user devices, the LTE RAN will be the largest part of the new infrastructure build-out. A study by Dell'Oro Group indicates steady 5 year growth with approximately $42 billion worth of mobile infrastructure revenues by 2014. No matter which study or forecast you read, the one consistent fact is the need for significant improvements in bandwidth and speed from user device all the way to the core.

The Evolution to 40G

This 'Need for Speed' was neither new nor a surprise and the industry has been working on this next stepping stone in communications technology for over four years. The foundation was laid a long time ago with the creation of Ethernet. More than 30 years later the reliability, simplicity and cost effectiveness of Ethernet has led it to a position of ubiquity as it remains the underlying technology for the Internet and all IP networks.

Recognizing the need for something beyond 10 Gigabit Ethernet, the IEEE 802.3 working group formed the HSSG (Higher Speed Study Group) in 2006. In line with the IEEE structure, the Task Force was officially approved and named P802.3ba late in 2007 and the first meetings were held in January of 2008. On June 17 of 2010 the IEEE 802.3ba standard was approved. The standard covers a group of different physical layer (PHYs) standards encompassing both 40 Gb/s and 100 Gb/s variants. The 40GBASE-KR4 PHY was defined for use in backplanes.

40GBASE-KR4 will enable 40G communications in a similar way that today's 10G AdvancedTCA backplane solutions are delivered, which is through the aggregation of four lanes. In the case of 10G, four lanes using the 10GBASE-KX4 PHY, each at 2.5 GB/s, add together to create a single 10Gb/s link. PICMG defines this as part of the standard version 3.1 option 9. From the AdvancedTCA system perspective, a single 40Gb/s fabric link will be created using a single MAC. At the backplane level there will be four discrete pairs each operating at 10Gb/s that will be aggregated within the switch, making it operate as if it is a single serial connection. The definition for a single 10G link is 10GBASE-KR (from IEEE 802.3ap). New backplanes will be designed to accommodate both capabilities with the distinction between four individual 10G links or one at 40G being made by the switch blades and payload cards.

Now that the IEEE specifications are fully approved, the PICMG 3.1 R2 subcommittee is working to complete the integration of these new Ethernet backplane options, which are targeted for ratification before the end of this year.

Establishing Interoperability

The standardization work done by the IEEE and PICMG contributes significantly to the evolution of technology in general. It is in the areas of compatibility and, most importantly, interoperability that the role of standards is crucial to the adoption and success of any technology. Any new or evolved technology must first fulfill a market need and meet the appropriate economic measures. An open standard, e.g., AdvancedTCA, then allows multiple vendors to adopt the technology and build their own flavors while maintaining adherence to the standard specification. Monitoring, testing and ensuring compliance with the specifications leads to an interoperable ecosystem and ultimately to a viable and healthy market for end products.

In the world of Advanced TCA platforms and in fact the whole breadth of PICMG's xTCA open specification, the Communications Platforms Trade Association (CP-TA) was formed with a mission to drive market adoption.  In order to achieve their mission, CP-TA works to actively cultivate a global ecosystem that delivers interoperable products and is focused on tests and tools to ensure this happens. CP-TA has three primary strategies defined.

• Verify product interoperability through the recommendation and development of xTCA interoperability compliance and test procedure documents.
• Create xTCA interoperability compliance guidelines based on the specifications and profiles developed by PICMG, Service Availability Forum, SCOPE Alliance, and The Linux Foundation.
• Develop and implement proactive marketing programs with the goal of fostering industry preference for interoperable xTCA building blocks and tools from CP-TA member companies.

The work of CP-TA creates ICDs (Interoperability Compliance Documents) and TPMs (Test Procedure Manuals) aligned directly with the PICMG xTCA specifications. The latest versions are ICD 3.0 & TPM 3.0, which are matched with the PICMG 3.0 R3.0 ATCA Base Specs. As PICMG release the new revisions of the specification that will cover 40G, CP-TA will then evaluate the necessary steps required for interoperability compliance and testing.

As we have seen, the build out of new network infrastructures such as LTE will continue, and indeed accelerate, as they work to keep up with the adoption of mobile devices. Likewise the application and service platforms that will feed and protect these devices will continue to evolve. Both technology segments require speed and bandwidth to deliver on their promises. The 40G backplanes built into the next generation of AdvancedTCA platforms will provide the necessary performance step-up with at least a 4X improvement over currently installed products. We can also be sure that as demand continues to increase (and we all know it will), the Ethernet working groups of the IEEE and the platform standards and compliance bodies such as PICMG and CP-TA - along with the ecosystem vendors that support them - will continue to have our backs.

About the Authors

Sven Freudenfeld provides North American Business Development for the Kontron AG line of AdvancedTCA, AdvancedMC, MicroTCA, and preintegrated OM solutions Kontron. He can be reached at: sven.freudenfeld@ca.kontron.com

Eric Gregory is Senior ATCA Product Line Manager at RadiSys. Eric can be reached at: eric.gregory@radisys.com

Rob Pettigrew is Director of Marketing for the embedded computing business  Emerson Network Power. Rob can be reached at: rob.pettigrew@emerson.com

Karl Wale is Director of Product Line Management at Continuous Computing. He can be reached at: Karl.Wale@ccpu.com