What protocols are used in LTE architecture?
Let me show you how LTE uses specific protocols to handle everything from setting up connections to securing data. When you’re working with LTE, you don’t just need the names—you need to clearly see how each one fits into the system and supports what you’re trying to do.
These are the protocols you’ll deal with in LTE:
- Radio Resource Control (RRC)
- Packet Data Convergence Protocol (PDCP)
- Radio Link Control (RLC)
- Medium Access Control (MAC)
- Non-Access Stratum (NAS)
- GPRS Tunneling Protocol (GTP)
- Internet Protocol (IP)
- User Datagram Protocol (UDP)
- Transmission Control Protocol (TCP)
- IP Security (IPSec)
- Internet Key Exchange (IKE)
- Session Initiation Protocol (SIP)
- Real-Time Transport Protocol (RTP)
- Diameter
- Extensible Authentication Protocol (EAP)
- Mobile IP (MIP)
- Lightweight Directory Access Protocol (LDAP)
- Hypertext Transfer Protocol (HTTP)
- Domain Name System (DNS)
- Simple Network Management Protocol (SNMP)
Here’s how you understand the key ones in action:
Radio Resource Control (RRC):
In LTE, RRC manages how your device connects to the radio network. It sets up, modifies, and releases radio bearers. When your device moves or needs resources, RRC handles it. So whenever you’re establishing a connection or switching cells, this protocol is making those decisions.
Packet Data Convergence Protocol (PDCP):
PDCP takes care of compressing IP headers and securing user data. If you’re sending packets, this protocol strips unnecessary overhead and applies encryption. That way, the transmission stays efficient and protected over the air interface.
Radio Link Control (RLC):
RLC ensures that data gets delivered accurately. If the radio link gets unstable, RLC breaks packets into smaller pieces, reassembles them on the other side, and fixes any errors. You rely on it to keep the data stream smooth and reliable between your device and the base station.
Medium Access Control (MAC):
MAC decides how and when devices can use the radio channel. It schedules transmissions, handles retransmissions, and deals with random access when a device first connects. When multiple users compete for resources, MAC prioritizes and manages access.
Non-Access Stratum (NAS):
NAS works between your device and the LTE core network. It handles signaling that’s not tied directly to the radio interface—like managing sessions, mobility, and authentication. So when your device registers with the network or initiates a data session, NAS is the one doing that work in the background.