I travel a lot and having a constantly reliable Internet connection is high on my priority list. Tethering from my phone is often times spotty. Different carriers are good in some areas and poor in others. To further complicate things, sometimes even a good connection can randomly hike packet loss rates and response times.

I'm searching for a solution. Something with much more reliability and consistency to tether my laptop to. I'm willing to pay for multiple carriers. I figure I can set something up with multiple sims that supports multipath tcp and then use a VPN connection to a AWS EC2 instance I setup and control.

So what I'm looking for is a dual active sim device that supports simultaneous LTE on both sims. So the first part of the question is what hardware device supports this?

According to Wikipedia there's a multipath TCP networking layer for Android. Is this standard in the latest version of Android or is this something I have to manually install?

I figure Android is a good way to accomplish this goal, but in the event that the hardware just isn't available, is there a non-Android solution that would accomplish the same thing while being as portable as a phone? I've seen professional units that accomplish this but they're bulky and have external power requirements that wouldn't fit in my pocket.

  • Consider also using speedify for combining wifi hotspots generated from 2 phones, also see this answer: superuser.com/questions/606307/… Dec 5, 2016 at 14:48
  • Hey there Daniel, you've got two answers to this question now! Does either one help? Could you accept the one that's the best?
    – owlswipe
    Jan 22, 2017 at 15:58

4 Answers 4


Android's multipath TCP networking layer is only able to use WiFi and Cellular concurrently and can't use multiple of the same connections at once (as far as I know).

However. You can use a mobile WiFi Router from Huawei for example. To get a seamless LTE and WiFi over LTE connection. The Huawei router is very fast and as big as my phone so very easy to carry. It offers about 8 hours of coverage but they have models that are slightly bigger that offer 20 hours.

This way you can use for example Samsung's download boost to use LTE and Wifi at the same time to get double the speeds/reliability. I would suggest you get sim cards from 2 major different providers for extra reliability so if one is under maintenance/has low coverage you can rely on the other.

I hope this helped if you have more questions feel free to ask.

*If you want to double your speed you might also want to look into NIC teaming I think this only works on windows / pc's though

  • 1) Is the download boost (LTE+wifi simultaneous) only available on Samsung phones or is it available on other modules, such as the Moto G 3rd gen (4g)? 2) Would it be available in future releases? Dec 5, 2016 at 13:27
  • 1
    As far as I know Samsung is the only one to preload it on its devices but it can be installed manually from the google play store have a look at "SuperBoost". - Root may be required Dec 5, 2016 at 13:42
  • I dont know if the app is still on the google play store but multipath TCP is required for it to work. If you do not have multipath TCP you can try flashing a kernel that does support it if you meet the hardware requirements. Dec 5, 2016 at 13:47
  • is this it? It's called Super Download: play.google.com/store/apps/… Dec 5, 2016 at 13:50
  • Yes that's it worked out for me although according to other people (My dad's S6) it does not work. So I'd say try it out first and if it does not work with the apps you need you might need to look for an alternative. Dec 5, 2016 at 14:12

Google's Project Fi is a carrier tailor-made for traveling so you don't need an additional hotspot. It's basically what you're describing above. Fi is less expensive than almost any other US carrier you'll find, aggregates signal from 4 different carriers, doesn't charge extra for international data, and supports voice calling and LTE data in 135 countries. For Project Fi, you'll need a Nexus 5X, Nexus 6P, or Pixel; the Nexus 5X is the cheapest (you can pick one up from Fi for $250 unlocked, with no contract).

Calling & texting is cheap and works from almost anywhere in the world—see the list of 135 countries here—and data comes from US carriers T-Mobile, Sprint, and US Cellular & UK network Three for $10 per GB. Using your phone as a hotspot is free (data costs the same $10/GB), and they'll even send you up to 10 free data-only SIM cards for your tablets (Android or iPad) and phones (Android or iPhone).

All in all, you might want to consider picking up a Nexus 5X for your travels; my 6P with Fi worked great during a recent trip to Canada.

Project Fi Website.

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  • 1
    +1 that's a promising option, thank you. At the moment you have to be a US customer to use it (as a UK resident, I just tried to sign up with my Google account but the page responded "Project Fi is available only for accounts in the US.") Maybe it will come to the UK in the future. For some, there is the privacy issue with Google. I recognise this concern but overcoming the frustration of patchy mobile internet is more important to me. Dec 5, 2016 at 21:52
  • @therobyouknow Pretty sure if you set your address to something in the US, it'll work just fine (weird that they have that restriction, especially since they include signal from UK carrier Three). Also pretty sure that Google won't actually get any more of your data, it only goes to their carrier partners (and besides, can't they just spy through Android if they want?).
    – owlswipe
    Dec 8, 2016 at 2:18
  • @owlswipe Android is open source so any data backdoors would probably have been found by now. The data can of course be taken from apps like gmail, google play store etc. Even if you search on google they can know your IP, Location if you allow it and more. Also the project fi is good because it has multiple carriers to switch between. If it only has one in the UK its kind of useless for the OP. Dec 8, 2016 at 7:30
  • I'm inclined to think that getting 2 (cheap) 4G phones and using speedify to combine their wifi hotspots is the best option for most flexibility albeit cumbersome with more devices 1) you can choose which carriers you want to use 2) it can work in any country 3) you can choose the tariffs offered Dec 8, 2016 at 10:40
  • 1
    @therobyouknow You can manually switch carriers in Fi: android.stackexchange.com/questions/154320/…. But yeah, 2 phones would do the trick too, maybe even better.
    – owlswipe
    Dec 8, 2016 at 12:04

I would suggest the best solution is speedify for the original poster as this service enables multiple internet connections, including LTE/4G, 3G, Wifi etc to be combined.

The original question caught my interest as I had the same issue with variable mobile coverage whilst on the move. In my example, I'm travelling up and down from Southampton to London Waterloo in the UK daily, I wanted better internet than one operator can provide. South West Trains do offer a free WiFi service which I am told bonds the 4 UK operators, however this is shared among all the passenger so can be unusable at peak times but is OK off peak.

I have awarded the bounty to Joost as they directly answer the original poster's question however I would believe that my answer provides the most flexible solution.


For my solution, I'm actually now using Speedify (speedify) - see my write up here: https://apple.stackexchange.com/questions/235813/how-to-use-bluetooth-pan-and-wifi-simultaneously-in-osx/272551#272551


Support for the Multipath TCP (RFC8684) is available for some slightly older Android phones, but it requires that the device be rooted. It allows for simultaneous use of WiFi and Celllular connections by TCP connections.

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