MicroTCA Spans Applications
Concept to Reality: An Application Architecture with MicroTCA
The flexibility and capabilities of AMCs and MicroTCA to develop embedded applications are endless. Even more rewarding is that COTS-based application-ready systems allow faster time-to-market with less development cost.
TONY ROMERO, PERFORMANCE TECHNOLOGIES
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Much has been written about the virtues of MicroTCA platforms and AdvancedMC (AMC) modules. Both of these technologies have been maturing and there are now numerous options and flexibility to configure a wide range of applications with products that exist today. So let’s explore in detail some application configurations.
In the examples below, we will look at all the components that are necessary to configure an end-user application. On the hardware side, this includes the MicroTCA chassis (which includes the backplane, power and cooling), the fabric switching such as Ethernet, PCI Express and SATA, IPMI Platform Management, and the AMC payload boards. The payload boards can range from processors, to storage/video, to I/O access cards. On the software side, this includes the Operating System, the Development Environment and, of course, the application software.
MicroTCA and AMC are COTS-based standards. As such, components from one vendor are specified to be compatible with other vendors components. This is highly beneficial, as it offers embedded designers with the freedom to choose components from as many vendors as necessary to configure their specific application. In fact, there are industry events occurring annually whereby multiple COTS vendors meet to verify compatibility between AMC modules and MicroTCA platforms, enabling cross-company product integration.
While it is fundamentally true that the chassis, mezzanine and MCH components from different vendors are compatible with each other, often a significant amount of time and resources are required in order to complete the integration process to ensure final product compatibility and configuration. This gets more complicated when you need to incorporate an operating system, development environment, APIs, drivers, and other software stacks besides the application.
So while on the surface, this seemingly wide range of options exists, there are several important nuances to AMCs and MicroTCA, whereby a single vendor who offers a full suite of hardware pre-integrated with software components can maximize the value of a configured system, increase functionality and performance, and guarantee full compatibility directly from the onset. Listed below are several aspects of a fully integrated platform, called an Application-Ready System.
One is configuration. A single vendor who can integrate their components together—and right out of the box, can ensure that these components are configured properly, that the appropriate onboard switches are set, and test to make sure the hardware and software components are compatible and functioning properly.
Another important aspect is unified tech support. If any technical issue arises, a single tech support group can more quickly debug and isolate the issue through all the components that are integrated together. Dealing with disparate tech support groups can lead to delays, as they may not be able to replicate the same configuration, or not clearly understand a third-party board’s specific issues. Or worse, blame another vendor for the problem.
Product uniformity may at first seem superficial, but this can range from the physical appearance, such as the labeling on the faceplates of the AMCs and platform, to functionality on AMC modules, software, or even firmware such as the sensor thresholds and FRU information that are programmed into the MMC management controller.
Management software is an essential element, and several MicroTCA system vendors provide Web-based management portals (Figure 1) that are typically programmed to enable off-site development, systems and module management, as well as monitoring of system-wide status and operations.
Screen Capture - MicroTCA web-based remote management tool, NexusWare Portal.
Finally, compatibility of the operating system suite with hardware must be assured throughout. In selecting a Linux software suite, make sure to consider a solution that provides all the necessary components such as Operating System, IDE, kernel builder, image builder, compliers, linkers, debuggers, cross platform development, hardware drivers, network services, platform management and Web-based system management. In addition, a suite that is developed to be specifically compatible with a suite of hardware not only ensures compatibility, but also provides synergistic features for an overall solution.
In all the application examples below, a 1U MicroTCA platform that houses six AMC slots is a perfect balance between having enough slots to house all the AMCs with room for scalability, but not more slots than will be cost-effective. What is also important to consider are the cost trade-offs between reaching the right level of high availability with going all the way to a fully redundant platform. Components that are most apt to fail, such as power supplies, fans, or hard drives, need to be redundant and easily serviceable. Electronic components on backplanes and/or motherboards have a high MTBF and offer a high level of reliability.
Example: Wireless Base Station
Data overload is already a reality with mobile operators, as consumers are rapidly adopting mobile smartphone devices and using them to download news and information from the Internet. One recent industry study involving millions of mobile device users indicated that these same users doubled their network usage in one year. 4G technologies, such as WiMax and LTE applications, are designed to handle heavy usage of mobile data. MicroTCA and AMC modules are a good fit with these types of applications, as they provide a carrier-grade platform with high-speed fabrics, high reliability, remote platform management and hot-swap functionality in a cost-effective form factor. Even defense departments are keyed in on wireless solutions for Network Centric Warfare communications. Wireless applications require real-time signal processing with high-bandwidth communications on and off the boards.
A 1U platform supports the four major functional blocks: 1) RF, 2) Baseband, 3) Control and 4) Transport. The AMC ecosystem offers AMC modules that support both the RF and Baseband functions on a single card or separate cards with a direct connection to the Remote Radio Head (RRH) for three-sector operation utilizing both a Xilinx FPGA and multiple TI DSP cores. The Control function is handled by a multicore processor AMC. And the transport for the backhaul is accommodated on Ethernet uplinks from the MicroTCA platform, or for legacy deployments, it can utilize a T1/E1 AMC module (Figure 2).
MicroTCA Base Station System of hardware and software components
The 1U MicroTCA platform is an ideal form factor with six AMC slots, as it can house all four functional blocks in a single shelf with room to scale to a second RF/Baseband AMC module if needed. Larger MicroTCA platforms that house 8 to 12 AMC slots are too large and are not cost-effective. For frequency and time synchronization of all the AMCs, the MicroTCA’s clock distribution can deliver a phase-synchronized Stratum 3 signal (e.g. 10 MHz or 30.72 MHz) to all the AMCs derived from an external Stratum 2 GPS Receiver outputting a 1PPS reference signal. In addition, if the GPS reference clock fails or is absent, a crystal oscillator can provide a holdover signal for a limited time until the GPS reference clock is back on line.
Example: Wireless and Media Gateways
A wireless gateway receives traffic from 3G Radio Access Networks or from a Mobile WiMAX Radio Access Network and aggregates traffic from base stations, manages the hand-off between the base stations, and provides quality of service. Here too, a carrier-grade architecture ensures hot-swap scalability, high availability and remote platform management. The two primary functional blocks for this application are packet processing and a control CPU. A high-performance, dual-core processor AMC can handle both functions, and housed in the 1U shelf, can scale up to six processor AMCs. The typical backhaul network is Ethernet to the Connectivity Service Network (CSN), and the quad 1GbE uplinks on the MicroTCA platform provide ample bandwidth (Figure 3).
A Wireless Gateway System
Media Gateways such as the ones that convert media streams from a Public Switched Telephone Network (PSTN) to an IP-based Network can also take advantage of the MicroTCA architecture. T1/E1 Communication Controller AMCs can receive multiple lines and perform high-performance and high-capacity processing via a PowerQUICC controller. These AMCs have onboard FPGA with the ability to transmit TDM traffic as I-TDM packets over the Ethernet fabric. In this example, the Media Gateway can scale up with more T1/E1 AMCs as subscriber traffic grows. Some modern Media Gateways also integrate Session Initiation Protocol (SIP)-based signaling and call control to function as stand-alone units for independent and intelligent SIP end-points. In addition to the operating system, the other software stacks that may be required are a SIP stack and/or SS7 MTP2 (Figure 4).
Another type of application that can take advantage of MicroTCA is carrier-grade, high-reliability, IPMI-based managed service appliances. Service applications can range from IPSec, deep packet inspection, load balancing, Quality of Service, traffic management, IVR and other content-based services. Deploying in a MicroTCA platform allows for hot-swap scalability by adding more blades dynamically as more service processing is required. It can also provide redundancy if one processor fails. Finally, raw processor blades, which have no physical storage medium and no OS or application installed, can be provisioned in real time as they are added to the system. These AMCs can be installed in a platform and undergo a Preboot eXecution Environment (PXE) to boot via the integrated Ethernet fabric in the MicroTCA platform. One of the processors in the system can act as a DHCP server to assign an IP address and send the client AMC a list of Boot Servers. This same AMC can act as the TFTP server to provision the new client AMC module with its operating system, application software and any data files.