Wifi/data problems in London

I'm on a good network (O2) and i often have problems getting 4G is certain parts of central London/Zone 1. I live in Zone 5 and have no problems there, but my wife who uses Vodafone sometimes does have issues. It's not just you, the networks in London can be awful. The fix i use is forcing the phone to use 3G, and it works ok if a little slower. Letting the phone select 4G/3G can grind everything to a halt.

On you Iphone's settings screen:
-select Carrier
-turn off the Automatic setting.
-it will then take a few minutes for the phone to generate a list of different carriers you can use. Select a different service it should help with the speed issues.

There is no wifi in the tunnels. Grab it for the moment you are in the station, if it works (not always for me) and expect it to fail as soon as the train reenters the tunnel.

Changing the carrier won't have any effect on the Wi-Fi speeds. When the phone is accessing cellular data, I vaguely recall that T-Mobile only provides 2G service in some areas. That could be part of the problem. I suspect you're aware of this.....

"When you travel abroad you will have unlimited data at up to 128kbps, which is great for web browsing, e-mail, social media and occasional use of certain features like GPS/maps. Some applications like streaming music or video typically requires higher-speed data for optimal functionality. If you frequently travel internationally and require a higher speed you can add T-Mobile ONE+ and get up to 256kbps speeds abroad for $5/mo."

I also came across this information on another forum which covers roaming with T-Mobile.....

"I know what 2G feels like (I previously had an iPhone 6) and it's barely usable--often emails won't even send. The 6s is WAY faster, almost native US LTE speed. So either they've upgraded the 2G speed, or I'm really getting 3G/LTE."

I don't have enough information to explain the information posted above. I'd have to do some further checking.

Changing the carrier won't have any effect on the Wi-Fi speeds

That goes without saying. But changing carriers can make data speeds faster if the carrier in one specific location is overloaded. Not all carriers have the same capacity in all areas.
My personal experience with using Tmobile in London is that data speeds are usually much faster than 2g, without paying anything extra.

I did pay for the higher speed data over here. That was my original point. My data speeds in Portugal, Spain and Germany were great. As soon as I landed in England, it was like my phone was in slow motion the whole time. It doesn't make any sense. I can't imagine the locals live with data speeds like this.

The carrier your phone has selected in the "automatic" mode is likely overloaded, switch to a different carrier with the instructions I gave above.

Thanks, Michael!! I switched to 3 UK and the signal and speed are much better. Not as good as in other countries in Europe, but better than the very sow EE network. My phone won't connect to either Vodaphone or the O2 network, so I guess I'll stick with 3 UK.

Thanks for these tips… I too have experienced slow data on my phone when I n London and didn't know why. I will use this advice on my next trip.

You're very welcome. If my memory is holding up I believe I was able to switch over to O2 as well. Sometimes it takes a few minutes to do a switch.

EE in independent tests comes out as the fastest network on average across the country, although of course there can always be local effects.

thank you everyone for sharing. I showed this post to my hubby cause he is the one who uses data when we are away. He said this will be very helpful when we go there in October.

course there can always be local effects.

There is also the possibility that some providers give priority to there own customers and throttle roaming users on top of the tmobile cap.

London has tons and tons of fast 4g, but it also has tons and tons of people using it.

I was reading, just a few hours ago, about the problems with London in the Which? Magazine, the UK equivalent of Consumer Reports, of how poor the perceived 4g is in London.

Of the 20 major cities in the UK with 4g, London is only 17th. Very poor.

That being said, when I go to London I'm out from the very centre except on weekends and I actually am pretty happy with what I get. I'm on perhaps the best network (O2). My work phone on EE has a lot of trouble keeping up... Then again my personal phone is a recent iPhone and the work phone is a newish but very old design Nokia Windows 10 phone (better than the old decrepit Blackberry I had until recently).

Sorry you didn't get what you needed.

The fact that two networks couldn't be seen at all suggests that there was some limitation on the phone, whether imposed by a lack of a network roam agreement or a technical one in finding the combination of frequencies etc, although I understand that the IPhone 6 should be able to receive all three frequencies used for 4G in the UK (the IPhone 5 on the other hand lacked the 1800Mhz band).

There are a lot of variables - even that the phone can get itself 'preferentially attached' to a distant mast rather than a close in one and it never changes cell.

I can see all four networks on my phone. I can only get service on EE and 3 UK. Maybe it depends on what part of London I'm in. When I tried to connect to Vodaphone or O2, I got "no service". I'm usually trying to get the information I need or get to my next destination, so I'm not exactly standing around London doing a scientific survey of signal strengths, lol. 3 UK has been working fine since I switched so I haven't seen a need to try the other ones. I'll be curious to see what it's like in other parts of England when I start doing day trips next week to York, Oxford and Bath. Thanks for all the input!!