Royal Caribbean's Oasis of the Seas houses 2,700 guest cabins and can accommodate 6,300 passengers and 2,160 crew members. The wired has 4,000 extensions including one in each passenger cabin. There are 1,100 IP surveillance cameras to monitor activity aboard ship, and 370 Cisco plasma and LCD IP touch screen signs placed around the ship post notices of daily activities. The screens can also be used by passengers to get directions to other locations on the ship, according to Max Schmidt, associate vice president of IT and operations, and Greg Martin, network manager for the cruise line.

All that gear is complex enough without introducing a that has to function inside spaces defined by metal hulls and bulkheads that wreak havoc with wireless broadcast patterns. "It's a challenging environment," Martin says. The ship is divided into zones that can be shut off with fire doors so impermeable that closing them actually alters the effective range of some of the access points, he says. "We need additional access points for that or the wireless signals will not penetrate," Martin says.

In all, it takes more than 900 access points -- all the gear is from Cisco -- to supply pervasive coverage throughout the vessel. Every cabin has wireless access, for IP phones or for Internet connectivity, and the cabin doors are heavy enough to affect wireless signals, he says.

Planners first designed the wireless network based on best estimates of how signals would be affected by the materials that make up the ship. Then as they were deployed within the ship, each access point was tweaked for power and orientation to achieve full coverage, Martin says.