The NYSE and the future of Wireless WiFi networks
Quite often you find an organization that pushes a technology to the edge of its capability so as to provide a glimpse into the future of that technology. The NYSE and the wireless network installed across the NYSE trading floor is one of those cases.The requirements at the NYSE pushed the limits of wireless WiFi technology in the areas of reliability, redundancy, roaming and capacity. The trading application being used on the trading floor required zero packet loss and equal performance across all traders. In terms of redundancy, half of the wireless network at the NYSE can go down and still be fully operational. In terms of capacity, it can provide 256kbps to over 100 traders gathered in a couple of 100 square feet. In terms of roaming, typical handoff times had to be on the order of 10’s of msec and occur every 8 seconds for a fast moving trader. I worked for over a year on the wireless network at the NYSE in designing, deploying and testing it. And what is currently operating on the trading floor is an 802.11a picocell network with 4 -6 APs typically covering every square foot of the trading floor and up to 10-12 APs in some areas. Additionally a custom 802.11 client with a preemptive roaming algorithm capable of handling a trader walking across the floor roaming every 8 seconds through APs typically covering 100 to 300 square feet. Many of the technologies needed in the NYSE wireless network such as variable receive sensitivity for creating picocells, secure fast roaming and preemptive roaming are now in Cisco’s unified wireless product. So while the wireless network at the NYSE took a significant amount of effort and a custom client, it demonstrates that wireless LAN networks can and are being used for critical business applications and has the technology deployed at the NYSE becomes productized, wireless networks in most organizations will increasingly move from the status of a convenience network to business critical network.