Guide To The Emerging Telecom Standards: Who Does What And Why

As service providers build out their broadband packet networks to offer enhanced triple-play services, telecom OEMs (TEMs) are working overtime to provide the equipment needed to deploy those services. Historically, TEMs have built this equipment from the ground up by using proprietary platforms. A growing number, however, is finding it increasingly difficult to deliver homegrown equipment in a timely, cost-effective fashion.

To enhance their competitive position, many TEMs are now utilizing open architecture platforms based on industry specifications and standards, which make it easier for them to outsource their equipment design and keep pace with the latest technology. Open platforms reduce the time and cost associated with designing and manufacturing telecom equipment, savings that are ultimately reflected in reduced capital expenditures for service providers. They also facilitate the design of modular, flexible telecom systems that are easier to scale, upgrade, service, and maintain, benefits that are ultimately reflected in reduced service provider operational expenditures.

Several organizations are working to define open platform standards for hardware, software, system integration, and high-availability design, including the PCI Industrial Computer Manufacturers Group (PICMG), the Linux Foundation, and the Service Availability Forum (SAF). Building on these baseline platform standards, industry groups such as the SCOPE Forum and the Communications Platform Trade Association (CP-TA) are also working on equipment profiles, application frameworks, and testing services that guide all phases of component selection, software development, integration, and verification. Meanwhile, the Mountain View Alliance (MVA) is emerging as an umbrella organization for providing system guidance, coordination, and marketing for all of these organizations.

Modular Architecture One of the first open platforms to pique the interest of equipment providers was CompactPCI, particularly after the addition of telecom-friendly features like hot-swap, a dedicated telephony bus (H.110), Ethernet-based packet transport (PICMG 2.16), and Integrated Peripheral Management Interface system management. More recently, however, ATCA has emerged as the dominant open platform for telecom infrastructure applications. Aimed squarely at next-generation packet networks, ATCA provides advanced features such as a high-bandwidth switched fabric, remote system management for individual modules, hot-swap, and provisions for implementing high-reliability architectures, all common requirements in telecom designs.

The Advanced Mezzanine Card (AMC) specification increases the modularity of ATCA systems, enabling OEMs to customize AdvancedTCA carriers with application-specific CPU, signal-processing, I/O, networking, and mass-storage capabilities. An ATCA card can carry as many as four AMC modules, giving designers a variety of potential configurations from a single card. And like an ATCA blade, AMC modules allow for remote system management and hot-swap for individual modules.

Building on the success of ATCA and AMC, PICMG has also developed a small-form-factor chassis specification targeting telecom applications with tight space and cost constraints. Known as MicroTCA, this specification defines a hot-swappable, switched-fabric chassis that can accept AMC modules directly, without the need for an ATCA carrier. With MicroTCA, designers can leverage not only the installed base of AMC cards, but also the same switched-fabric, transport, and management protocols.

The software foundation for telecom systems starts with the operating system (OS), typically carrier-grade Linux, which provides advanced high-availability features such as failure detection, fail-over, and hot-swap management (Fig. 1). The middleware extends the OS, providing advanced interprocess communications, event logging, fault management, and network management services that speed the development of portable, scalable applications.

The hardware platform interface adapts the software for a particular hardware architecture, while the application interface specification (AIS) layer couples applications with the system software platform. Application software sits atop this hardware/software platform, providing the vendor-specific service enhancements that TEMs use to differentiate themselves from their competitors.

Open Standards Follow System Structure Efforts to develop open standards and specifications for building telecom systems follow the same basic structure as the system design. Each layer requires its own set of documents, with a host of industry consortia developing those requirements. An entire standards and specifications ecosystem has emerged from this combined effort. Some groups address the needs of a specific layer. Others address the interfaces between layers, testing, and overall coordination.

The telecom standards ecosystem begins with the open platform building blocks, including the interfaces between those blocks (Fig. 2). Several organizations are involved in the definition of open platform standards.

PICMG is responsible for hardware specifications such as ATCA, MicroTCA, and Advanced Mezzanine Card. All three hardware specifications are now well established, but PICMG’s efforts aren’t over. Currently, the group is defining specifications for a ruggedized version of MicroTCA that addresses the needs of harsh working environments.

It also recently completed the hardware platform management specification (HPM.1), which will allow firmware downloads. A change in form factor for ATCA, ATCA300, is undergoing definition as well. And, change notices for ATCA and AMC.1 PCI Express are under way to resolve issues and upgrade performance specifications.

On the software front, the Linux Foundation continues to develop standards for a carrier-grade, Linux-based operating system. Meanwhile, the Service Availability Forum (SAF) is tackling the specific needs of high-availability system design, defining the management functions and interfaces that building blocks must offer. OpenSAF has assumed stewardship of an open-source implementation of SAF’s application interface specification (AIS).

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The SCOPE Forum seeks to influence the specifications being developed by PICMG, SAF, and the Linux Foundation, as well as other carrier-grade definitions. SCOPE has published a hardware profile for ATCA systems (now at V2.0) and AMC Port mapping. It also has recently completed work on similar profiles for AMC modules and MicroTCA systems. The Forum’s software efforts include profiles for carrier-grade operating systems, high-availability middleware, and virtualization.

As standards groups plug away at open specifications for building telecom systems, they need to do so with an eye to other industry efforts.  For example, the Optical Internetworking Forum (OIF) targets the optical communications links used in telecom systems. Working with companies all along the supply chain, from semiconductor to system vendors, this organization creates implementation agreements that address a variety of issues, specifying how elements in the optical network must be created to ensure interoperability. 

Other industry organizations oversee how the network is to behave and place constraints on system design. For example, the Internet Engineering Task Force (IETF) is a collection of users, developers, academics, and other interested parties that oversees the Internet and its operation. It creates some behavioral standards that equipment designs need to support. Also, it supports standards and specifications from other organizations that help ensure the Internet’s continued viability.

System Profiles Map Standards To Real-World Systems To help vendors of telecom hardware and software building blocks, the telecom industry itself has begun defining reference system profiles. These profiles outline the hardware and software needs of various types of telecom equipment in terms of the tasks the equipment is to perform and the functions it needs to perform them.

Profiles give developers a specific product target, which helps ensure that the standards and specifications that building-block vendors define and use adequately address the telecom equipment developer’s needs. A number of such profiles are now in place, including ATCA-based and MicroTCA-based central-office system hardware profiles, an OS profile, and a base platform middleware profile.

The industry has developed a similar set of references to guide application interface development. The reference application frameworks are full system applications implemented in software and isolated from the platform hardware design. This provides software standard/specification developers with specific product targets to guide their development efforts. Both a radio network controller and a media gateway reference framework are available, developed under the control of the Open Communication Architecture Forum (OCAF) Focus Group of the International Telecommunications Union (ITU).

Interoperability Testing While standards and specifications go a long way toward ensuring that developers will produce building blocks that system integrators can combine as needed, they invariably leave some details open to interpretation. Such ambiguity can result in interoperability problems.

To address these issues, and to ensure that developers properly adhere to the standards, some form of independent testing must be in place. In the telecom ecosystem, various industry groups offer component testing and certification as well as system-wide testing. PICMG, for instance, runs a series of hardware interoperability workshops where vendors can come together to test their implementation of the specifications.

The Communications Platform Trade Association (CP-TA) also focuses on the interoperability of ATCA, MicroTCA, and AMC hardware, and it is working to gain industry acceptance of standard interoperability tests. The group has released version 1.1 of its Interoperability Compliance Document (ICD) for ATCA, and a related Test Procedure Manual (TPM) is also close at hand. CP-TA also is developing ICDs and TPMs for both AMC and MicroTCA systems as well as associated test tools.

With multiple standards organizations working independently on hardware and software specifications, profiles, frameworks, interfaces, and testing, there is a risk that these efforts may diverge and/or compete and that component suppliers and telecom companies will work at cross purposes (see the table). To coordinate these organizations and allow them to leverage each other’s results, representatives have come together to form the Mountain View Alliance. Essentially, the MVA is acting as an umbrella organization for these groups, providing system-level guidance and marketing support that promotes synergy between the standards and ensures that component suppliers and telecom companies are working toward the same end.

Outsourcing Standards Expertise Staying abreast of new developments can be extremely challenging for companies developing telecom components or systems. Yet maintaining a current understanding of these standards and specifications is essential for those companies to participate in the market. Their products must comply with the standards and interoperate with other vendors’ products to be competitive and successful.

One way to maintain this currency is to make a substantial investment in attaining the required expertise. This requires first becoming familiar with the relevant standards and specifications, their scope, and their application. Next, the company must join the various organizations to ensure that it has immediate access to revisions as they arise as well as a clear view of how the standards and specifications are evolving over time. Maintaining this level of activity often requires dedicated personnel.

The alternative approach is to work with vendors who are already engaged with standards organizations. Such vendors will have in-depth understanding of current standards and specifications, advanced knowledge of pending changes, and even input into future enhancements. This level of insight helps ensure that the products these vendors offer are up to date, have proven interoperability, and offer a growth path for future system evolution. Using such products as building blocks makes it easier for TEMs to create competitive designs that comply with current and future industry specifications.

Proprietary systems are rapidly fading in the telecom industry, giving way to standard COTS alternatives that provide easy access to interoperable, best-of-breed technology from multiple suppliers. These systems can be developed and manufactured in less time at a fraction of the cost of proprietary systems. They’re also easier to maintain, scale, and upgrade. Navigating the standards maze and moving from a proprietary design to an open platform can seem to be a daunting proposition. But partnering with a standards expert can ease the transition.