However, wireless networks do have their vulnerabilities, as numerous recent disasters have made all too clear. The most recent example is the devastating series of earthquakes in Gujarat, one of India's most industrialized states, on January 26 this year. The strongest quake measured 7.9 on the Richter scale and killed over 20,000 people, making it India's worst quake since 1956. The other cellco, Fascel, suffered similar outage problems. The story is more or less the same in other earthquake disasters, from Turkey to El Salvador to Taiwan, the latter of which saw 4,000 base stations between six mobile operators knocked out of service when the island experienced its worst earthquake of the 20th century in September 1999.
Floods can also wreak havoc on cellular networks.
In flood-prone areas of countries like China, Vietnam and Bangladesh, for instance, flood waters have been known cause damage to base stations, or in some cases wash them away completely. Interestingly, however, base station damage isn't always the problem when cellular networks get knocked out of commission. Indeed, base stations are designed to withstand unusual environmental conditions, to include earthquakes. Most base stations are built to comply with NEBS Seismic Zone 4 requirements, based on Bellcore's earthquake risk zones in the US, with Zone 4 being the highest. Base stations built to that standard are tested by the manufacturer to withstand earthquakes as powerful as 7.1 on the Richter scale, and many equipment cabinets have been known to withstand actual earthquakes that registered even higher.