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The author:(作者)qqpublished in(发表于) 2015/6/6 7:30:22 Comprehensive coverage of Shanghai Metro WiFi： free
Mobile is too expensive? Free Metro Wi-Fi has arrived! According to reporter learned exclusively, Shanghai Metro Wi-Fi as early as at the beginning of the end of 2014, a low-key test, at present, the Metro Line 13 line across the open wireless signal, known as the "peanut subway tests Wi-Fi".
A month later, passengers will find Shanghai Metro, Shanghai Metro will be providing free Wi-Fi . Silver Valley contractor South of Shanghai Metro Wi-Fi related sources, already on line Line 13 of the test results will soon be announced, other subway lines will also open in tests. Other lines are tension-building at present, all Shanghai Metro line will ultimately provide Wi-Fi service.
However, another bad news is that different from the Wi-Fi building March, 4G difficult to signal a short time on the subway, ", by the letter of the three operators, General Authority and the shentong Metro company has opened a number of coordination, but there is no progress. "A 4G construction of Metro operator who told reporters that apart from Line 13 new five-line part of the concourse line platforms opened the 4G signal, other old line and 4G when the construction will be started in the tunnel, shentong Metro company, such as" PASS card ".
Measurement: 2M Shanghai Metro Line 13 line wireless rate Wi-Fi low-key test starting from the end of 2014, Metro Line 13 opening of the whole line was named "peanut subway tests Wi-Fi" wireless signal. On June 1, 2nd, reporter on Line 13 line full test Wi-Fi signal, the effect is rather good: from the station Hall after you log on, subway line, did not appear cut off, open the page very smooth, video playback there is little Cottonwood, tachometer software Speedtest shows download speed of 2Mbps, upload speed is 1.38Mbps, connection time is about 10 seconds.
"Peanut Wi-Fi" is not new. 2014 opened in Shenzhen Metro Wi-Fi needed to pass a name as "peanuts" App to connect to the Internet, the contractor for the silver Valley in the South, according to its public information throughout the country have contracted to 2100 km of Metro Wi-Fi line, silver Valley occupies the South 70%.
After the opening of the Shenzhen Metro Wi-Fi, has attracted ridicule: there are no network signal, inexplicably kicked after logging ... ... Cause attributed to low bandwidth. Metro Wi-Fi bandwidth from 4 g signal, but ground 4G signal access to signal the end of natural attenuation, thus affecting Wi-Fi bandwidth has been converted. Construction of Shanghai's Metro Wi-Fi take a different approach, using cable, platform a p 4G signal relay system, dynamic broadband 400M, can at least satisfy 600 users.
Silver Valley in southern sources, Shenzhen Metro Wi-Fi also in accordance with the modification of the original model.
4G there is no timeframe, "Corporation's argument is that no report to prove right now, 4G CBTC signal does not affect Metro's control system and user information PIS, so it cannot be 4G into the tunnel construction. "On line Line 13 of the carriage, when iPad Wi-Fi after a login when playing video, reporter 4G signal on the phone but never came, one operator who is the explanation.
Wi-Fi used to be the largest subway signal system problems, as with the 2.4G band, disturbed, Shenzhen Metro Wi-Fi signal was 3G converted the passengers themselves, "force stop", South of silver Valley technical focus, Wi-Fi and CBTC in the same frequency band is divided into tracks, its relative isolation.
4G with CBTC and is on a different frequency, China Mobile's TD-LTE frequency bands allocated to provide 1880-1900M, 2320-2370M, 2575-2635M, FDD-LTE band 1800M and 2100M for China Telecom, China Unicom's FDD-LTE band 2300-2320M, 2555-2575M, Telecom Taifeng communication laboratory Ling Wei, Deputy Director of the Institute of science and technology told the times of IT Said in an interview, although in theory there may be risk of interference between different frequency bands, but it should be through technical means can eliminate, the subway may be more concerned about users conversion of 4G into Wi-Fi and interference between the CBTC.
"If Metro Wi-Fi works well, user requirements are met, operators may not be good news for the 4G construction. "Operator who some of the above concerns. According to 2012 STO and three home operators signed of Shanghai track traffic new five line public communications facilities resources using contract, Metro in of communications line will has telecommunications operators itself construction (previously mode for Metro company construction, telecommunications operators rental), to 2014 end of, new five line platform station Office of 4G site Basic has construction completed, but tunnel in of 4G construction always not get Metro company of agreed, this means with user in Metro driving process in the cannot using 4G Internet.
However, according to the silver Valley in the South, Chairman of development prior to an interview of the week to disclose information in order to meet the needs of individual broadband, a train holds up to 600 users, after entering the user will not be able to connect. The industry believes that, if you want to ensure passengers can connect to the Internet, 4G, and Wi-Fi still need to complement each other.
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