[moshepupkin]

The issue of seamless mobility between WiFi and cellular seems to be a rather hot topic with operators these days. There are a lof of ongoing activities in various standardization bodies 3rd Generation Partnership Project (3GPP), Wi-Fi Alliance (WFA), Wireless Broadband Alliance (WBA) and GSM Association (GSMA) to name a few. However, in reality, till any of these standards such as Mobile IP get actually deployed in the field by operators the problem of providing uninterrupted experience to the user lies in the hands of mobile app developers.

Some apps, especially these that use HTTP as a transport protocol can cope with this, even though the IP address usually changes when the phone switches to/from Wi-Fi. However, for many apps your mileage can vary.

Hence the question — what the developers can do to ensure seamless experience for the user when the phone moves from WiFi to cellular and vice versa?Are there any tutorials and best practices to follow?

As a user, I hate it when my Skype call drops or streaming audio gets interrupted when I enter my house. As a developer, I'd like to be able to create apps which do not suffer from these issues.

[RudiVisser]

In all honesty I think it's safe to say that if you're developing an always-connected mobile application you should be expecting drops and reconnections (from the same IP or otherwise) within a same user session.

It's not just a problem with switching from WiFi to Cellular, because as far as I'm aware a good OS wouldn't recreate a connection anyway so long as the other one was still open. But it's a problem with everything, mobile networks are unreliable - period.

[moshepupkin]

RudiVisser, on 17 September 2012 - 03:29 AM, said:

But it's a problem with everything, mobile networks are unreliable - period.

I disagree. 3G is pretty reliable, 3G call drops are very rare. In theory, Skype can be as reliable as 3G voice. In theory, again (at least with mobile IP), voice calls can survive switch from Wi-Fi to cellular.

[RudiVisser]

moshepupkin, on 17 September 2012 - 02:23 PM, said:

I disagree. 3G is pretty reliable, 3G call drops are very rare. In theory, Skype can be as reliable as 3G voice. In theory, again (at least with mobile IP), voice calls can survive switch from Wi-Fi to cellular.

It's not that 3G is reliable it's that calls are constantly routed through different things seamlessly.

This is why you don't drop calls when you're moving, even though you're switching towers all the time. It's also why you don't drop calls switching between 3G and 2G networks, and different 3G modes too (Edge, 3G, HSDPA, etc). Mobile internet however, is a different story entirely, and (at least in England) can be unreliable even with a good signal.

This post has been edited by RudiVisser: 17 September 2012 - 06:30 AM