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London tube WiFi spec - 2Ghz versus 5Ghz?


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Old 21-12-2013, 10:36
brianw100
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The London tube now has WiFi on most platforms in Zone 1.

What is its spec - 2Ghz versus 5Ghz?

I commute from West Hampstead (Jubilee line) to Charing Cross (Bakerloo) and the trains arrive and depart really fast at the stations nowadays.

So the limiting factor in using WiFi now is: how fast does your phone connect, and how fast does it logon so that comms can start before the doors close and you are into the next tunnel!

The capacity of the WiFi is impressive.

I made a Skype call on my mobile from the carriage of a Piccadilly line train stopped at Russell Square the other day! The other passengers thought I was faking!

Questions for the Techheads out there:

1. My current (underspec) Galaxy Ace 2 only has 2Ghz WiFi. If I had a phone with 2GHz and also 5Hz WiFi, would I be better off using the 5GHz frequency? The platform WiFi routers are clearly visible down the platform, so the range advantage of 2GHz would not be a factor, would it? What about curved platforms when the WiFi routers might not be in line of sight aerial to aerial? (Or did TfL and Virgin/EE think of that and place extra routers on curved platforms?)

2. How on Earth does the router on the platform handle a train full of commuters with mobile phones suddenly arriving out of a tunnel? (Crush Standing 137 persons per car x 7 cars = 959 passengers per train. Frequency: One train every 90 seconds!!) OK - so only a small number would have phone WiFi enabled and be setup for TfL WiFi logon, but still...

3. What is the deal on Overground stations where, confusingly, TfL have struck a deal for "The Cloud" to provide the service?

Brian
London
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Old 21-12-2013, 10:46
TheBigM
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Given the very short time you are on the platform, 2GHz vs 5GHz makes little difference at the moment, connecting and authenticating eats up most of the time.

I believe they would be set up with 2.4GHz frequency as that is more common on phones and tablets. They may also have 5GHz I don't know.

Right now, it's more designed for people waiting for a train rather than those already on a train. The other day at a central line platform in the middle of a weekday, there was a 14 minute gap between trains.
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Old 21-12-2013, 13:52
LostFool
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Whenever I've tried to use the Virgin wi-fi at Tube stations I've found that a train has arrived before I've had chance to connect. It's a good idea in principle but I haven't found it very useful in practice. It could do with an auto-connect ability.
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Old 21-12-2013, 13:54
qasdfdsaq
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2. How on Earth does the router on the platform handle a train full of commuters with mobile phones suddenly arriving out of a tunnel? (Crush Standing 137 persons per car x 7 cars = 959 passengers per train. Frequency: One train every 90 seconds!!) OK - so only a small number would have phone WiFi enabled and be setup for TfL WiFi logon, but still...
I've not actually been to London since the system was setup, so I don't know the intricate details. However the Virgin Media setup is a fairly specialized Alcatel Lucent enterprise setup that's been specifically engineered and stress tested exactly for that scenario - hundreds of users arriving per minute.

It's not actually that hard on the "router" anyway, the "router" are just dumb bridges (actually, access points) and don't really do anything, it'll be a centrally controlled LWAP setup.

As for the 2Ghz vs 5Ghz debate, I don't know how mad Londoners are with their phone usage these days but it generally won't be a huge advantage. Maybe slightly better call continuity for voice calls.

I've run wireless networks in the past which had to support upwards of 500 devices in a room (mostly students or conference guests) and rarely hit congestion even without load balancing enabled.
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Old 25-12-2013, 15:09
jonmorris
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I use the Virgin Wi-Fi service quite a bit in the tube and believe it's 2.4GHz only. I can perhaps 60-70% of the time arrive at a station and connect quick enough to do a refresh or send an email before leaving and losing the connection (and repeating at the next stop).

Of course, I've also let a train go and remained on the platform to use it without disruption. I often use it to upload videos to YouTube. As my phone or camera will do 1080p video at a high bitrate, I can easily get files in excess of 100MB. Thanks to Virgin's impressive back haul, I can upload these incredibly quickly.

The Wi-Fi service has to be one of the best I've ever used anywhere. Only a few notable exceptions at events, where high usage was properly planned for.
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Old 25-12-2013, 22:30
qasdfdsaq
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Yeah the general standard of free/public wifi in the UK is fairly low, though there's a few exceptions.

There's a backpacker's hostel in Edinburgh that use Virgin Media's 100Mb business fibre (actual ethernet, not HFC) that means regularly 50Mb+ uploads. I was also mighty impressed in Switzerland where all the hotels I stayed in (granted, all business hotels) easily did 40Mb down, 40Mb up on their wifi.

Here in the UK getting more than 5Mb from a free service is a chore.
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Old 26-12-2013, 01:26
jonmorris
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Well, it does seem that more and more places will likely offer speed capped Wi-Fi and charge for decent speeds. Then they can still appear to offer free Wi-Fi even though it will be next to useless.

Hotels in particular.
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Old 26-12-2013, 01:59
alan1302
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Well, it does seem that more and more places will likely offer speed capped Wi-Fi and charge for decent speeds. Then they can still appear to offer free Wi-Fi even though it will be next to useless.

Hotels in particular.
Even with caps as long as you can surf the next, grab your e-mails and watch a video on YouTube what more do you really expect from a free service?
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Old 26-12-2013, 02:29
qasdfdsaq
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A lot of "inclusive" services I've had at hotels have been capped at between 128k and 2Mbps.

Not always enough for any of the above.
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Old 26-12-2013, 10:31
enapace
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That's true even some Five Star Hotels I've stayed at have been stingy with WiFi speeds. It is understandable though as they do have to provide this service to all the rooms.
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Old 26-12-2013, 10:50
LostFool
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That's true even some Five Star Hotels I've stayed at have been stingy with WiFi speeds. It is understandable though as they do have to provide this service to all the rooms.
Yes, it can be difficult. First of all you have the problem of putting in the infrastructure to provide a signal through large buildings which are often old and with complex architecture. Then you need to make sure that a single user doesn't dominate the bandwidth. Plus you have the cost of providing a commercial internet connection at a reasonable level. There's a huge difference in cost between a domestic 50 Mbps service and a 100 Mbps commercial one.

Too many hotels try to do it on the cheap which is why hotel wi-fi is notoriously unreliable. This is understandable when it's free but when some chains charge over £10 per day then they really should invest in some enterprise standard infrastructure.

However, these days, a good internet connection is as important as electricity and hot water in hotel rooms.
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Old 26-12-2013, 20:26
alan1302
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A lot of "inclusive" services I've had at hotels have been capped at between 128k and 2Mbps.

Not always enough for any of the above.
You can surf the net, check e-mails at those speeds and I know You Tube works at 1.5 Mbps so I'm not sure really what the issue with it is It's a free basic service that lets you do the basics.
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Old 26-12-2013, 20:54
qasdfdsaq
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The 2Mbps was if you paid extra.

The standard service was 128k.

That was so god-awful slow even for web browsing that despite being in Italy I opted to pull out my 3G phone and tether to it.
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Old 26-12-2013, 21:33
enapace
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Yes, it can be difficult. First of all you have the problem of putting in the infrastructure to provide a signal through large buildings which are often old and with complex architecture. Then you need to make sure that a single user doesn't dominate the bandwidth. Plus you have the cost of providing a commercial internet connection at a reasonable level. There's a huge difference in cost between a domestic 50 Mbps service and a 100 Mbps commercial one.

Too many hotels try to do it on the cheap which is why hotel wi-fi is notoriously unreliable. This is understandable when it's free but when some chains charge over £10 per day then they really should invest in some enterprise standard infrastructure.

However, these days, a good internet connection is as important as electricity and hot water in hotel rooms.
Completely agreed I regularly travel and stay over night in various major cities across the UK. Actually will be in Manchester for 6 Days next month. I sort of need a solid connection to do business. For the price I pay for the room/suite I don't think it is much to expect a decent internet connection.

Honestly these days I just use my phone to tether in major cities you can normally get a solid 4-8MB connection on Three when you tether. Might even see faster speeds if 4G is released next month as scheduled.
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Old 26-12-2013, 22:01
Three
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Here in the UK getting more than 5Mb from a free service is a chore.
5Mbps if you're lucky. The Cloud hotspot at Bristol Temple Meads doesn't work at all during rush hour mornings. O2 WiFi hotspots seem to run at around 1-2Mbps in most places I visit, although I've seen as high as 10Mbps on the occasion.

It's quite shocking really that if I visit a McDonald's and hook up to the O2 WiFi I'll get around 1-2Mbps, whereas the WiFi on buses around here which are connected to 3G for their backhaul run at around 6-7Mbps.
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Old 26-12-2013, 23:48
qasdfdsaq
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Hah, the buses around here use Vodafone for their backhaul and rarely get above 1Mbps. I LOL'd the first time I used it this year, spend about two minutes testing it then switched to my 40Mb+ 4G phone tether instead.

As per typical Vodafone fashion, the intercity buses drop to EDGE outside the major population areas and having spoken to one of the guys who looks after the fleet, it's cause they get a good deal on Vodafone and customers just don't give enough of a damn for them to upgrade it.

The trains (also free) I've seen doing over 30Mbps on occasion.
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