What is the MCC and MNC?
Today, let’s take a closer look at MCC and MNC, two important identifiers used in LTE and all other mobile networks. Since we’ve already talked about topics like Tracking Area and eNodeB, it’s a good time to understand how the network actually identifies where a mobile subscriber belongs. This is where MCC and MNC come in. I’ll explain it to you in a way that makes this concept clear and practical.
MCC: Mobile Country Code
Let me start with MCC. This is a 3-digit code that uniquely identifies the country of the mobile subscriber. Every country in the world has its own MCC, and it’s always used together with MNC to fully identify a network.
- MCC is used during initial attachment when your device connects to a network.
- It helps the device and the core network know which country the SIM card is registered in.
- Even if you’re roaming in another country, your MCC tells the visited network your home country.
MNC: Mobile Network Code
Now, MNC is the Mobile Network Code. It works closely with MCC. While MCC identifies the country, MNC identifies the specific operator within that country. It’s usually a 2-digit or 3-digit number.
- MNC tells the system which mobile operator you’re subscribed to.
- Together with MCC, it forms a unique identity for your operator globally.
- It’s used in network selection, roaming decisions, and billing.
MCC and MNC Together
When combined, MCC and MNC create something called the PLMN ID (Public Land Mobile Network Identifier). This ID is used by the network to recognize which operator and country a subscriber belongs to. You’ll see this being transmitted during the initial network selection phase or in SIB1 (System Information Block 1), as we’ve discussed earlier when we went through the structure of LTE signaling.
| Parameter | Meaning | Example |
|---|---|---|
| MCC | Mobile Country Code | 310 (USA), 404 (India) |
| MNC | Mobile Network Code | 10 (AT&T), 45 (Jio) |
| PLMN | Combination of MCC + MNC | 310-10 (AT&T USA), 404-45 (Jio India) |
Where You See MCC and MNC in Action
You’ll find MCC and MNC in several parts of LTE operation. Let me point out a few cases:
- When a UE powers on, it reads MCC and MNC from the SIM and searches for a matching PLMN in the available networks.
- In the tracking area update, the UE includes its MCC and MNC to tell the network its identity.
- During roaming, the visited network uses this combination to check if your home operator has a roaming agreement.
So now you can see how MCC and MNC are essential for identifying where you belong and how the network routes your services. Since we earlier covered how Tracking Areas are defined, you can connect the dots — because those areas are assigned to PLMNs identified by MCC and MNC.