The next new network

Of the two dominant CDMA infrastructure vendors, Nortel Networks is taking the most neutral approach to UMB and its competing technologies. “Is Nortel committed to UMB? I'd say we're invested in OFDM/MIMO,” said Danny Locklear, director of global CDMA marketing. Nortel is currently pursuing all three OFDM/MIMO technologies, and while those product paths will eventually diverge, much of the core radio access development can be shared between them, Locklear said.

Although the UMB standard is scheduled for final 3GPP2 ratification in April, typically a new technology won't see daylight until two or three years after approval. That means the first early adopters of UMB won't be in network trials until 2009, Locklear said. Nortel obviously has to make a decision to fully commit to a UMB product line before then; however, there is still time to see whether the market embraces the technology or not. If it does, the OFDM/MIMO work it has done for LTE and WiMAX can easily be applied to UMB. And if the market doesn't, UMB work can be redirected to a certain extent into LTE and WiMAX. How the market will play out, however, is ultimately out of Nortel's hands and in those of the CDMA carriers, Locklear said.

“It will take a significant number of the Tier 1 carriers to commit to the technology for it to take off,” he said. Traditionally, the CDMA carriers have always been quick to adopt newer network technologies because of the 3GPP2's faster standards and development timelines. In the U.S. in particular, CDMA 1X and EV-DO launched long before their general packet radio services/enhanced data rates for GSM evolution and UMTS equivalents. “For UMB, it would take that same leadership from those operators to drive the market,” Locklear said.

It's those time-to-market advantages that UMB proponents believe will give the technology its edge. Ratification for the final LTE standard is expected in September, only five months after the UMB is finalized. Furthermore, the 3GPP has frozen the physical layer specification for the LTE radio link, allowing vendors to begin radio interoperability testing — something Ericsson said it has already begun.

LTE may seem hot on the heels of UMB, but James Person, chief operating officer for the CDMA Development Group, said it isn't the starting point that counts, but how quickly the contestants get to the finish line. The cultures of the 3GPP and the 3GPP2 are vastly different, Person said, with the 3GPP being a primarily regulatory-body-driven organization that plods through the standards after numerous waves of consensus. The 3GPP2, by contrast, is a much nimbler, industry-driven organization, Person said, demonstrated by the numerous occasions it has brought a better-performing technology to market much quicker than its GSM counterpart.

“You've got different cultural approaches to the standard,” Person said. “Historically, that has given us the time-to-market advantage.”

In addition, to those timing advantages, UMB can provide CDMA operators a continuity path that LTE and WiMAX can't offer, Person said. Although UMB will require new networks and new handsets, they will be built within the same ecosystem that has delivered technology to CDMA carriers for a decade. The availability of dual-mode UMB/CDMA handsets is assured, as well as support for a handoff between the CDMA and UMB networks themselves, Person said. The UMB radio infrastructure may require a new network footprint, but the interfaces to every other aspect legacy network would be built with CDMA integration in mind, he said.

And as for the idea of requiring an entirely new network build, there are steps vendors are taking to minimize the scope and scale of such an undertaking. The world's largest CDMA vendor, Alcatel-Lucent, has invested significant resources in ensuring a UMB network deployment would be as prohibitive to CDMA carriers as the upgrade to EV-DO, said Mike Iandolo, president of Alcatel-Lucent's CDMA/EV-DO business. Those carriers wouldn't just be able to slip in new modem cards and throw up an extra antenna — they would have to deploy new base stations, Iandolo acknowledged. But considering many of these new 4G launches will be over new spectrum, carriers would be forced to build out a new network footprint whether the deployed LTE, UMB or even a CDMA 1X system.

Alcatel-Lucent, however, is designing its EV-DO Rev. A base station with the necessary radio frequency components to support UMB, Iandolo said. The difference between Rev. A and UMB will basically be software and an antenna upgrade; the remaining components of the network, from base station controller on, will be the same gear CDMA carriers have been deploying for the last year, Iandolo said. “We have to design the network so that upgrading the radio infrastructure is no big deal,” Iandolo said.