A Skyscraper So Tall Builders Can't Use Walkie-TalkiesIf you want to build a skyscraper 2,275 feet tall, you will face engineering challenges comparable to those of the Space Shuttle just because its sheer size. One of them is communications. When the unbelievable Burj Dubai started to get really high, the construction workers discovered one problem that seems obvious now: their walkie-talkies stopped working as they climbed the structure. The reason was simple: distance. At the beginning of the construction they used walkie-talkies-which are light, durable, and have a long battery life-across the site. However, these stopped working after some time, as the tower kept raising over the desert. With unreliable communications, Samsung Corporation-the main contractor-had to turn to a different kind of link between workers to avoid misunderstandings that may have jeopardized the safety of workers (even more, because plenty of people have had fatal accidents in the tower) and delayed the project. Fortunately for them, they turned to mesh networks, which are similar to the ones used in mobiles, but local. For that they used a company called Firetide, using several Wi-Fi-enabled VoIP phones over a HotPort wireless mesh, which also serves as the transport for the security video in the site.