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Post by trt on Nov 21, 2012 16:38:56 GMT
Full article at www.theregister.co.uk/2012/11/21/wi_fi_knockout/"Shenzhen Metro is blaming customer Wi-Fi for disruptions to its service. The subway system for the city of Shenzhen in Guangdong province, China, depends on the unlicensed 2.4GHz band to link up its signalling systems. "Engineers trying to keep the network running reckon black-market devices are kicking out three times the amount of official gear. They add that once eight of either kind come into range then the Metro's signalling system stops."
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Post by chrisvandenkieboom on Nov 21, 2012 17:00:16 GMT
Why didn't they license the use of another radio band? I guess a metro system qualifies for a special radio band? I think the safety of passengers is more important than costs...
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Fahad
In memoriam
Posts: 459
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Post by Fahad on Nov 21, 2012 17:13:15 GMT
Interestingly this is the band the Cityflo 650 CBTC system, due to be implemented on the SSL very soon, uses. Why didn't they license the use of another radio band? I guess a metro system qualifies for a special radio band? I think the safety of passengers is more important than costs... The cost difference is pretty massive, though - 2.4GHz and 5GHz equipment is a hell of a lot cheaper, even if we disregard licensing costs EDIT: Furthermore, there's no risk to passenger safety - trains should automatically apply the emergency brakes when they don't know where they are or can't communicate with the SCC, or know there are other lost trains in the area
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