Based on the speed of light, the theoretical limit for sending information between New York and Chicago is 7.96 milliseconds. Right now, the state-of-the-art among microwave service providers is about 8.5 milliseconds, Persico said, noting how different providers are trying to secure the fastest rights-of-way and are developing technologies with the lowest latencies, all in an effort to offer the fastest sub-millisecond services for financial firms.
"We've been looking at [microwave technologies] for about a year now, in both Europe and the U.S.," said Ian Jack, head of the U.S. infrastructure business for the New York Stock Exchange, during a panel discussion on the topic. "We're looking at what the vendor community is doing and trying to leverage that as much as possible."
Performance is still a big factor, Jack said. Performance "is one of our big challenges as a potential buyer. If you look at the actual uptime for services, it's not brilliant. Every vendor has a new change, a revelation just around the corner, but we have yet to see that."
Rain can hamper performance with microwave technologies. So can low-lying clouds. "Interference can bring an entire network down, and you don't have that with fiber-optic networks," Persico said. He noted that, eventually, microwave technology vendors will compete more on how robust their networks are, once they offer approximately the same latency times.