While high-speed optical fiber might be the way to go for large national research networks, point-to-point microwave connections have emerged as key links between financial exchanges.  The reason? Ultra-low latency. With widespread interest in sending the timeliest data possible, two separate microwave networks on both sides of the Atlantic are improving their technology: Europe's Persus microwave network, which connects customers to the NYSE Euronext exchange (as well as the Eurex exchange in Brussels and other European locations), along with McKay Bros. in the United States. While reducing latency is the goal of any network, it’s especially critical for ones used by financial institutions. The algorithms used by high-frequency traders must be acted upon within microseconds—a key reason why trading firms build their data centers as close to exchanges as possible, to minimize round-trip latency. (Those that don't depend quite as much on low-latency connections, including branch offices, can build farther away.) The Perseus network has three point-to-point connections: the first connects the NYSE Euronext and Liffe in the London suburb of Basildon to the Deutsche Bourse and Eurex in Frankfurt, Germany; the second links BATS, Chi-X, Turquoise, BOAT, and EBS in Slough, England to the Deutsche Bourse and Eurex in Frankfurt; and finally, there’s a shared connection between the London Stock Exchange (LSE), London Metal Exchange (LME) and Thomson Reuters in London and the Deutsche Bourse and Eurex in Frankfurt. It takes 4.6 milliseconds to traverse the approximately 740 miles between the NYSE facility in Basildon and the Eurex in Frankfurt. That’s roughly 579 million miles per hour. The Perseus network isn't foolproof; wind and weather can degrade it or bring it down. But Persus Telecom says that it maintains 99 percent uptime, with a dedicated fiber network as backup. SLA agreements are balanced against bandwidth-management policies, giving customers guaranteed bandwidth but not preferential treatment. That’s evidently appealing, because Perseus is seeking additional commercial customers. “Perseus has seen a strong demand for high-speed microwave technology since our preliminary launch last year; in fact, that initial capacity quickly sold out,” Jock Percy, the chief executive of Perseus Telecom, wrote in a statement. “Since then, we have provisioned additional capacity to meet customer demand and remain the fastest available microwave service between London and Frankfurt." Meanwhile, McKay Bros. said that it had achieved an 8.27 millisecond round-trip latency between Aurora, IL and Secaucus, NJ, along with 8.23 milliseconds’ round trip between Aurora and 165 Halsey St. in Newark—basically, exchanges in New York and Chicago. The latter is a distance of about 738 miles as the crow flies, or about 323 million miles per hour. McKay didn't say that it offered a backup fiber network, but it did boast 99 percent uptime during trading hours in December and January. To improve reliability, it is installing new ODU600 radios from Aviat Networks, which should boost transmission power by a factor of six, helping to blast through inclement weather. For now, microwave networks are specialized solutions for those operations that require the lowest latency possible. But as financial institutions continue to build out their datacenter infrastructure, these links will become even more critical.   Image: everything possible