Dicas para construir melhor uma rede wi-fi municipal

Um artigo publicado no PC World dá quatro dicas para construir uma boa rede Wi-Fi municipal. São elas: Instalar mais pontos de acesso que o necessário; Não colocar transmissores muito distante um do outro; Evitar partes aglomeradas do spectrum; e Considerar uma arquitetura centralizada WLAN. Abaixo trechos do artigo. A dica veio do Observatório das Cibercidades.

"1. Install more access points than you think are needed.

Having more access points improves reliability, throughput and capacity, says Craig Mathias, principal of Farpoint Group. "People try to get as much range as possible out of access points, and that's the wrong thing to do with any radio-based device," he says. "Back when access points cost a couple thousand bucks, it was a good [money-saving] strategy. But now that they're pretty cheap," usually $400 to $600, that strategy no longer is warranted.(...)

2. Don't place transmitters too far off the ground.

Too often, a network designer takes a transmitter designed to be placed 18 feet to 20 feet above the ground and figures, why not put it 50 feet up and see if it works better, says Leonard Scott, an IS manager for the city of Corpus Christi, Texas. That's not a good idea, and it can cause a number of problems, he says: "When a device is elevated far above the ground, the receiver has difficulty picking up the users on the ground." Twenty feet is about the height of a short utility pole, notes Scott, who has deployed a wireless network that covers Internet access for Corpus Christi residents and the applications used by city employees. (...)

3. Avoid crowded parts of the spectrum.

Even though major chipset suppliers are phasing out support for the 802.11a WLAN standard, Newman recommends using that standard when possible. "If you have enterprise-class gear today, there's a pretty good possibility it supports [802.11a]. If you can do it, turn it on," he says.The 802.11a standard helps with optimization because it operates in the little-used 5GHz band and therefore suffers less from interference than the newer 802.11g standard, which operates in the very crowded 2.4GHz band. "Not only is wireless LAN stuff using that band, but so are some cell phones, microwave ovens, cordless phones. There's not enough spectrum for all the devices licensed to use those frequencies," Newman says.(...)

4. Consider a centralized WLAN architecture.

Deciding whether to use a centralized or a distributed architecture is very much "a religious debate," Newman says. A centralized architecture uses a controller to manage all access points, whereas a distributed architecture requires that access points be managed individually."I tend to agree with those who say [centralized is better for optimization], because you can set whatever characteristics you want to set once . . . and they get pushed throughout the enterprise," Newman says. Those characteristics include an access point's radio-frequency settings, as well as QoS mechanisms that prevent delays in voice and video traffic, he says."