Vodafone Germany has started improving and expanding its mobile network in the city of Hamburg, and expects to complete the job next month, TeleGeography reports, noting that this program is expected to improve voice quality of Vodafone’s network in Germany’s second largest city, as well as double 3.5G data transfer rates, to 42.2 Mbps through the use of dual carrier (DC)-HSPA+ technology.

The UK-based company, which has about 23,000 base stations nationwide, is spending around 4 billion euros ($5.5 billion) on its mobile network for the next two years.