What is GERAN in LTE?
Let me explain to you what GERAN means in the context of LTE, especially if you’re trying to understand how different generations of mobile networks are connected together. You might have come across the term GERAN while exploring LTE or network integration topics, and it’s essential to know what role it plays.
GERAN stands for GSM EDGE Radio Access Network. It’s the radio access network that includes both GSM (Global System for Mobile communications) and EDGE (Enhanced Data rates for GSM Evolution) technologies. GERAN is basically the 2G radio part of the network, and it includes the base stations and controllers responsible for handling mobile traffic in those older networks.
Now, you might ask – why is GERAN even relevant in LTE, which is a 4G technology? That’s a great question. The answer lies in how networks are designed to work together to provide broader coverage and service continuity. Even though LTE is much faster and more advanced than 2G (GSM/EDGE), GERAN still exists in many regions and continues to be used for voice and low-data services. LTE networks often need to interwork with GERAN, especially in areas where LTE coverage is weak or unavailable.
Here’s how GERAN connects with LTE:
- Inter-RAT (Radio Access Technology) Handover: If LTE coverage drops or if you’re in an area without LTE, your device can hand over to GERAN for basic services like calls and SMS. This handover ensures service continuity.
- CSFB (Circuit Switched Fallback): LTE is based on packet switching and doesn’t natively support voice calls (which are circuit-switched in 2G). So, when you make a voice call in an LTE network, your phone may fall back to GERAN to complete the call.
- Coverage Support: GERAN fills coverage gaps in rural or less developed areas where LTE deployment might not be complete.
To help you visualize this, think of GERAN as the safety net in mobile communication. When LTE isn’t available, GERAN is there to ensure you can still make calls or send texts. From a network perspective, LTE and GERAN are often tightly integrated through the core network components like the MME (Mobility Management Entity) and SGSN (Serving GPRS Support Node), depending on the fallback path.
In our earlier discussions, we talked about how LTE networks interoperate with legacy systems like UMTS (3G). GERAN is another part of that legacy family, and understanding it gives you better insight into how seamless mobile communication is maintained across different technologies.
So when you hear GERAN in the LTE context, remember that it’s all about backward compatibility. Your device and the network work together to choose the best available radio technology to keep you connected, and GERAN is an essential part of that fallback strategy, especially for voice and basic data.