While major CDMA operators like Verizon Wireless (NYSE:VZ, NYSE:VOD) and Sprint (NYSE:S) are moving directly to 4G, the CDMA Development Group and other CDMA proponents have long stressed there is an alternative, EV-DO Revision B, which would allow operators to boost capacity without building new networks or acquiring new spectrum. ZTE, however, isn’t taking sides in the argument. Instead, it’s splitting difference, annoucing today a new base station that will support both the Rev. B upgrade and LTE on the same platform.
The Rev. B upgrade essentially works by stacking multiple 1.25 MHz EV-DO Revision A channels on top of one another, creating a single wideband high-capacity channel. Rev. B doesn’t improve upon the overall capacity of the individual channels, so technically the total capacity of the overall network does not increase. But by creating a single large carrier, the average transaction time for every user decreases—files download faster, Web pages load more quickly—allowing the network to move more quickly onto the next user and next transaction. The phenomenon, explained by queuing theory, leads to higher capacities available to each individual user, if not in the network overall. ZTE said its trials have achieved over 9.3 megabits per second on the downlink and 5.3 Mb/s on the uplink over 3 bundled carriers, but it has developed a system that could support up 15 carriers, providing download speeds as high as 73.5 Mb/s.
Meanwhile, LTE is a fundamentally different technology using different modulation and antenna configurations to achieve much greater network capacity over the same spectrum. The problem is LTE requires new licenses and a new network, two luxuries not every CDMA operator enjoys. ZTE also predicts that large-scale LTE rollouts won’t occur until 2012, so it’s betting even those operators with the money and the spectrum to deploy LTE will need an upgrade path to hold them over for the next few years.
Many CDMA operators in the US have written off Rev. B, but recently the technology has enjoyed a revival in other parts of the world. Last month, Wana, a CDMA operator in Morocco, completed a Rev. B trial using ZTE gear. Both China Telecom and South Korea’s KDDI have also committed to Rev. B trials, and the CDG claims several other operators have trials in progress or in the works.
By building a dual-mode LTE-EV-DO Rev. B platform into its software defined radio base station architecture, ZTE is targeting both the Rev. B enthusiasts and those that are sitting on the fence. If operators can get both technologies out of the same infrastructure, ZTE seems to be asking ‘what’s the risk?’