You can obtain a cell phone number either by signing a contract with a mobile phone provider or by purchasing a pre-paid card. A contract with a mobile phone provider usually lasts 24 months. It is possible to pay off a new cell phone together with the monthly standard charge. A prepaid means more freedom and flexiblity, but the connection rates are usually higher compared to the contract option. Doctoral researchers should enquire about special offers for students.
In order to have a landline at home, you need to sign a contract with a telephone company. You can compare the prices and services of various providers on the Internet by entering search terms such as "Handytarife" or "Telefontarife vergleichen". Before you sign a contract please enquire whether it accepts the use of call-by-call prefixes with which you can make international calls at particularly cheap rates. You can check on the Internet which provider of call-by-call prefixes is currently the cheapest.
If you do not have a landline, you can use public telephone booths or telephone cafes. In telephone cafes you can phone abroad at relatively cheap rates or alternatively purchase special telephone cards.
You can access the internet either through a telephone line or the cable network. Please look up providers on the internet for the area where you live and compare their conditons. The contract usually lasts 24 months. The period of notice is often three months to the end of the contract period.
By purchasing a mobile internet stick you are not bound by any contract and can go online anywhere. The rates are however considerably more expensive than with a landline or cable network connection.