Free WiFi at all MRT stations by 2020
By Teo Kai Xiang | Yahoo Newsroom – 4 hours agos
sigh.. • Report Abuse
I don't see the necessity in having free Wi-Fi in MRT station as one will only spent few minutes in there waiting for train unless the Wi-Fi still works while we are in the train. I think the ones whom benefit are those working in the station.1 Reply
i iskandarS • Report Abuse
i think its more practical to instal are wifi in trains rather than stations. But oh well....
- ricky l • Remove
How can wifi be install in train?
wifi are using access-point that need to connect by copper wire to LAN switches (poe or non-poe) that in turn require connectivity to Internet which again is wired.
When a train is moving, the wifi access point connected to LAN will snap.
It is not like 4G, or 3G where everything is wireless with long range rf signal. Wifi is a short range signal that do not exceed 100m which in turn need wired connection - and definitely not on a moving train. -
ricky l • Remove
If you can't visualize how wifi are installed in mrt, imagine your home :-
(1) You will have a fiber optics connector that are connected to Telco internet service by fiber - a wired connection to Internet.
(2) At home, you will have an Wireless internet gateway (Access Point) with wired connection to the fiber optics connector plus wifi which can be IEEE802.11a/b/g/n.
(3) Your home notebook, PC or mobile devices will have wifi adapter - for wireless access via wifi - using either radio frequency of 5Ghz or 2.4Ghz with the Access Point.
(4) You can walk around your home with your end devices within 100 meter or less - as long as your signal strength with your Access Point is strong - and this Internet gateway will route its traffic to the Internet via your Internet service provider. -
ricky l • Remove
Now at MRT, many WiFi Access Points will be planted throughout the MRT station - to ensure the RF signal overlaps to maintain signal strength and the authentication with the Access Points will not drop - when commuters sign-in an maintain connectivity with the wifi access points as the commuters walk in the MRT station.
L
All the MRT wifi Access Points will be connected by copper wire to the LAN network switches (using power-over-Ethernet or power injector). All the LAN network switches will in turn be connected to the router at the MRT command centre or data centre. The router at the command centre or data centre will have connectivity to Internet, so that commuters can access the Internet via this Internet connectivity.
The distance between the wifi access points to commuters mobile devices cannot exceed 100 meters. The LAN switches to the router in data centre cannot exceed 100 meters.
But on a moving train, if wifi access point is planted in the train, how does the wifi access point connect to the LAN switches using copper wire of 100meters? And how does the LAN switches connect to the router at data centre via copper wire to access the Internet service provider?
Unless there is an elastic copper cable that can stretch from the train to the MRT station as the train move - and when it reach 100 meters, the train have to stop. Then all commuters will have to board another train and travel another 100 meters and stop and go on and on until they reach the destination.
Then wifi on the train is possible.
Lau • Report Abuse
Ricky L, you made it very completed, Wi fi is possible inside a train without using a cable or wire. The same principle that employs to your mobile phone. The Wi Fi router can connect to a service provider using the mobile telecommunication network, sometimes called Wireless Wide Area Network.
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