O2 Carrier From
Slovakia

The O2 Carrier From Slovakia is denoted by codes: 231 06. The followings IDs are called HNI (Home network identity). This code is created by the combination of two other Mobile Country Code (MCC) and Mobile Network Code (MNC). The first three numbers stand for the MCC and they are used in order to identify the region which the carried comes from (in the following example it’s Slovakia). The last numbers of the HNI code are equal with the MNC and this ID is given for the specific mobile network operator.

Besides O2 Slovakia has assigned country code + 421. This number + 421 is equal with international calling code and it’s simply the telephone dialing prefixes used for calling O2 numbers.
O2 uses 2 GSM bands, 1 UMTS bands, 5 and 0 CDMA bands.. You can read the specific frequency bands in the table below. All bands of the O2 are display in MHz units.
Another important information in O2 Slovakia architectures is the standard of used protocols. It also uses 6 protocols such as GSM, UMTS, LTE, CDMA. The ISO standard code of O2 is SK. You can see more info about this mobile network operator at https://www.o2.sk/. How to check O2 coverage? How to check if your phone will work in Slovakia?