[anothercomment]

How is the network in a foreign country being picked? Here in Germany, we have (at least?) three competing networks, O2, Telekom and Vodafone. Their coverage differs, but afaik I don't get to automatically use another network if my network doesn't cover my location.

So what happens in another country? Free roaming won't be much use if no network covers my location? If on the other hand, I will be allowed any network for the price of my home network, I wonder if it would make sense to get a contract in another country, so that I can use all networks in Germany for free?

[AnssiH]

> So what happens in another country?

You will get a network that has a contract with your operator. The roaming regulations basically require the foreign networks to meet all reasonable requests for roaming: http://berec.europa.eu/eng/document_register/subject_matter/...

> I wonder if it would make sense to get a contract in another country, so that I can use all networks in Germany for free?

There are fair use clauses that allow the operators to charge for permanent roaming: http://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A3... (section 3)

[perlgeek]

I heard [1] that SIM cards have a preference built in for networks, often over 100. But you can override that if your smartphone OS allows that.

[1] in this German podcast: https://www.heise.de/video/artikel/Podcast-c-t-uplink-17-5-D...

[pieterhg]

Operators usually have preferred networks when roaming. If not available I think they fall back to the one with the most reception at time of switching.

[Someone]

Don't German networks have agreements to route traffic for other operators if they don't have coverage somewhere? That would surprise me.

And the rules are made to make it difficult to get that contract in a different country, as you aren't allowed to roam for 12 months a year for free.

[germanier]

They don't. The gaps in coverage are very small at least for basic phone service. LTE is available for at least 93%/90%/80% of the area respectively for the three networks. Good coverage is also the main factor of competition.

[mschuster91]

They did, at least O2 had a inland roaming with Telekom back in its early days; after the merge between O2 and EPlus the networks are still doing inland roaming afaik.

And I'd say with O2 you don't get anywhere next to 90% LTE - not in the countryside (where Vodafone and Telekom often enough also offer EDGE at best), but also in major cities. Berlin is the worst (at Hbf and Gesundbrunnen you're lucky to have actually working HSDPA!), next comes Hamburg and Duesseldorf. Munich is fairly good, also in the subways.

The general problem with O2 is when the network gets congested - e.g. demonstrations, festivals, sometimes on Autobahns even traffic jams! - there is no Internet service at all. The phone may show a "4G" indicator but no traffic goes through. Telekom and Vodafone seem to handle sudden congestions way better, I am not sure how though.

[germanier]

Sorry, I edited my comment while you replied. O2 officially is at 80% LTE coverage according to the latest BNetzA report. But as far as I know they often use cells that can't handle the needed capacity.

When the networks where new, some offered roaming in some areas, I remember that as well. The E-Plus/O2 roaming was more of a technical thing when they merged, it should now be largely gone and a single network.

[mschuster91]

It's iirc their backhaul network that can't keep up, not the technology they use in their BTS. Telekom and Vodafone have large fiber networks (Telekom for DSL, Vodafone for cable-Internet) so they can use existing infrastructure (conduits, electricity lines, right-of-way for houses housing concentrators, routers etc) while O2/Eplus had to build out/rent everything.

In addition O2/Eplus historically got the cheaper but more inefficient frequency ranges which made them the "low cost" players.