MicroTCA User Interview with Alok Shah of Vanu.

Conducted by Lance Leventhal, Technology Editor

Vanu provides wireless infrastructure solutions that enable operators to access new markets and develop new revenue streams. Vanu’s software radio access network (RAN) solutions utilize Software Defined Radio (SDR), providing tremendous flexibility. The Vanu Anywave basestation is the first FCC-certified, commercially available software RAN solution, whereby a single reusable hardware platform can support multiple wireless services and standards simultaneously. Each standard is entirely developed in high level languages that run on high volume, high performance commercial off-the-shelf (COTS) processors, allowing customers to choose the best and most cost-effective one for their application.

1. Why did you choose MicroTCA?
Because it meets all environmental and regulatory requirements for best current basestation practices and also ensures high levels of availability and performance. Hardware scalability and the available interconnects allow for higher capacity provisioning and provide full scope for longer-term serviceability. The architecture’s failover mechanisms, hot-swap functions, and manageability layers all adhere to open standards, allowing us to meet uptime goals and adapt open interfaces to our remote management software suites. Lastly, the large number of vendors building AMC cards provides access to many processing platforms and external interfaces.

2. What platform were you using previously and why did you decide to change?
Instead of using proprietary hardware, such as ASICs, DSPs, and FPGAs, the entire GSM and CDMA2000 standards, including the physical layer, are writ­ten completely in high level C++ software running on general purpose processors. The multi-standard basestation  can then run on industry-standard servers. MicroTCA provides a more scalable offering in a smaller footprint.

3. Are you using a vendor-supplied platform or developing one in-house? Why did you make this choice? If you are using a vendor-supplied platform, whose is it?
We are using a vendor-supplied platform cost-optimized for our application. The platform conforms to and retains all the advantages of the open standard MicroTCA specification while meeting our stringent cost goals. The ability to optimize the platform to provide 12 full-size payload slots in 3U was crucial to meet our multi-sector, multi-standard support needs. The platform is from Advantech who demonstrated to us previous capabilities in design-to-cost system development for Tier-1 TEMs.

4. Did you face cooling and power distribution problems?
In the design phase with Advantech, customized cooling and power designs were key to reaching our overall 3U footprint goal. However, most challenges were met then, and we had no significant problems with the initial prototypes. To remain within a 3U envelope with 12 payload slots, we decided to implement rear access power modules and extend the carrier’s depth. Power was implemented with Advantech-designed MicroTCA compliant modules hosting an enhanced module management controller (EMMC), power switching, monitoring, and control circuitry for both payload and management power. Input power was derived from half-brick based modules that convert -48V to 12V. In addition, two power modules needed to be connected on a unit to provide 1+1 redundant conversion. In that way, each power unit can supply two MCHs and four fan units (shared between both power units for failsafe operation), as well as six AMC slots.

For optimum cooling, we grouped two 80mm fans which are hot swappable from the front. Each fan cools one MCH and 6 AMC slots. Each unit has a dual fan controller which monitors speed and control supply voltage. At power on, the fans run at maximum speed until the MCH sets the level. In normal operation, the MCH will control the levels as required to keep operating temperatures for the AMCs within range. However, the controller on the fan unit also has an autonomous background control mode which activates if the MCH fails.

5. Have you implemented shelf management? If so, what software did you use?
Advantech’s latest MCH implements full shelf and carrier management. Remote management is implemented using RMCP (IPMI over Ethernet), using the IP backhaul interface.

6. How do you interconnect your MicroTCA boards?
The processor AMCs are interconnected to Advantech’s next generation MCH which provides a switched gigabit Ethernet network to all boards on the base fabric.

7. How did you debug and test your MicroTCA system?
We debugged the system using our own in-house test software suites and test harnesses. Final debugging was completed during internal network trials.

8. Did you find any interoperability issues?
So far there have been none whatsoever. Interoperability between the MCH switch and a full payload of 12 processor AMCs (PrAMCs) has been fully tested. IPMI is working well with the power modules and fans, as well as with the PrAMCs. Advantech has also performed extensive interoperability testing with selected suppliers whose products provide future connectivity options. Failover support between MCHs was initially a concern, but is now functional and meets our requirements.

9. How large is your system and how much throughput does it provide?
It is a 3U MicroTCA chassis with 12 useable AMC slots. The system provides bottom-to-top cooling in 3U. With a special sloped air-duct design, it also provides front to rear cooling in 4U when stacked. The system is designed for gigabit connectivity on the base fabric, and Advantech is currently investigating a 10 GbE upgrade.

10. Are you using middleware? Is it Service Availability Forum-compliant?
We are currently investigating several third-party HA middleware options for the platform, all of which are SAF-compliant.

11. Do you use AdvancedTCA also or are you planning to use it?
Vanu has tested AdvancedTCA-based solutions successfully, so we can deploy that technology if necessary. However, MicroTCA is a better fit for cellular basestations, given their cost and environmental requirements. The performance levels obtained with MicroTCA and Intel–based PrAMCs are sufficient to meet current customer needs, we can adjust PrAMC density to raise basestation capabilities over time.

12. What is your opinion of MicroTCA? Will you use it in other products?
MicroTCA provides significant performance ,and meets the processing requirements for Software Defined Radio (SDR) while providing advanced levels of reliability. We think that it will mature into a leading open standard technology in the wireless basestation market.

13.  How has MicroTCA worked out in terms of effort and return on investment?
It’s too early to tell. Vanu’s SDR Anywave basestation lowers CAPEX and OPEX costs as it can run a GSM and CDMA basestation over a common hardware platform, partitioning the two diverse systems in software. With this system, many rural operators can increase their roaming revenues without incurring additional CAPEX while ensuring that their OPEX remains relatively low over the longer term.

Commercial-off-the-shelf MicroTCA pricing was originally perceived as prohibitive when compared to rackmount server solutions. However, when designed to cost, as Advantech did here, the lower price premium for the extra value makes a compelling business case for MicroTCA.

It’s important to note that the key differentiating factor for Vanu is the company’s perception of itself as a software firm rather than a hardware OEM. Vanu develops software applications  can run on many commercial off-the-shelf hardware platforms. We believe that the wireless infrastructure industry is transitioning from vertically integrated suppliers to an ecosystem with component specialists and system integrators. value shifts That can be achieved only if the software is decoupled from the hardware, allowing it to run on multiple platforms. Vanu can then take advantage of Moore’s Law, have an open architecture, and provide hardware-based price-performance improvements. As long as MicroTCA hardware costs continue to track standard server hardware and its delta does not increase, the ROI will be highly positive.

14. What is the single most importance piece of advice you would give to those planning similar projects?
When selecting vendors, look at their past performance and their customization expertise. Check out their past and present interoperability roadmap and embrace open discussions with their ecosystem. Where possible, use COTS hardware, but remember that some vendors are more flexible on cost-optimization than others, so challenge them on their past projects and insist on customer references wherever possible.

Alok Shah is Principal Technology Analyst at Vanu. You can contact him at abshah@vanu.com.