Powerline Communication (PLC) lets electricity meters talk over the grid wires they are already connected to — no separate radio infrastructure needed. Two competing OFDM-based standards have emerged as the serious contenders for smart grid PLC: PRIME and G3-PLC. Choosing between them is a multi-decade commitment.
Why PLC for Smart Metering?
PLC uses the low-voltage (LV) power distribution network as the communication medium. Advantages:
- No separate radio network to install or maintain
- Meters are always connected to the power line
- Works in dense urban environments where RF can struggle
- No spectrum licensing — the LV network is already owned by the utility
Challenges: the power line is a noisy, variable channel. Household appliances inject interference; impedance changes with load; signal attenuates at distribution transformers.
PRIME: PoweRline Intelligent Metering Evolution
Origins
PRIME was developed by Iberdrola (Spain) and the PRIME Alliance from 2009 onwards. It became the dominant PLC standard in Spain and was adopted for France’s 35-million-meter Linky deployment and other Southern European markets.
Technical Specifications
| Parameter | PRIME v1.3.6 | PRIME v1.4 (ITU-T G.9904) |
|---|---|---|
| Frequency band | 41.992–88.867 kHz (CENELEC A) | 41.992–88.867 kHz |
| Modulation | OFDM, 96 subcarriers | OFDM, 96 subcarriers |
| Modulation schemes | DBPSK, DQPSK, D8PSK | DBPSK, DQPSK, D8PSK, QAM-16 |
| Max PHY data rate | ~130 kbps (D8PSK) | ~500 kbps (with QAM-16) |
| Network topology | Tree-based (Base Node → Switches → Service Nodes) | Mesh-capable (v1.4+) |
| Application layer | DLMS/COSEM | DLMS/COSEM |
| ITU-T standard | G.9902 (v1.3) | G.9904 (v1.4) |
Network Architecture
PRIME uses a Base Node (concentrator at the MV/LV substation) that manages a tree of Service Nodes (meters) optionally via Switch Nodes (meters acting as repeaters). Each substation covers its LV feeder — typically 50–200 meters in European networks.
Key Deployments
- Spain: Endesa, Iberdrola, Naturgy — ~29 million meters
- France: Enedis Linky — 35 million meters (largest single PRIME deployment)
- Italy: E-Distribuzione 2G programme
- Portugal, Brazil, Chile
G3-PLC: Grid Third Generation PLC
Origins
G3-PLC was developed by ERDF (now Enedis, France) and Maxim Integrated in 2009–2011, then standardised through the G3-PLC Alliance. Despite France later choosing PRIME for Linky, G3-PLC gained significant traction in Asia-Pacific and North America.
Technical Specifications
| Parameter | G3-PLC (CENELEC A) | G3-PLC (FCC band) |
|---|---|---|
| Frequency band | 35.9–90.6 kHz | 154.7–487.5 kHz |
| Modulation | OFDM, 36 subcarriers | OFDM, 72 subcarriers |
| Modulation schemes | DBPSK, DQPSK, D8PSK, QAM-16 | Same |
| Max PHY data rate | ~34 kbps | ~200 kbps (FCC band) |
| Network topology | IPv6 mesh (6LoWPAN over PLC) | IPv6 mesh |
| Application layer | DLMS/COSEM or CoAP/LwM2M | DLMS/COSEM or CoAP/LwM2M |
| ITU-T standard | G.9903 | G.9903 |
The IPv6 Architecture
G3-PLC’s most distinctive feature: it is built on 6LoWPAN — IPv6 over Low-Power Wireless PANs, adapted for PLC. Every meter gets a link-local IPv6 address. The mesh network uses LOADng (Lightweight On-demand Ad hoc Distance-vector Next Generation) routing. This makes G3-PLC natively IP-addressable — you can ping a meter. PRIME requires additional adaptation to support IP.
Key Deployments
- Japan: TEPCO, Chubu Electric — largest G3-PLC deployment, ~28 million meters
- South Korea: KEPCO — national smart meter programme
- USA: Several utilities (FCC band)
- India: Major component of RDSS programme smart meter rollout
Head-to-Head Comparison
| Criterion | PRIME | G3-PLC |
|---|---|---|
| Raw data rate (CENELEC A) | Higher (130 kbps) | Lower (~34 kbps) |
| Network topology | Tree (Base Node hierarchy) | IPv6 mesh (self-healing) |
| IP-native | No (requires adaptation) | Yes (6LoWPAN) |
| Robustness on noisy lines | Good | Excellent (adaptive tone masking) |
| Installed base | ~65 million (Europe) | ~35 million (Asia-Pacific) |
| Ecosystem maturity | Very mature | Mature |
| ITU-T standardisation | G.9904 | G.9903 |
| Application layer | DLMS | DLMS or LwM2M |
Which Should You Choose?
- Choose PRIME if: you are a European utility, your HES vendor ecosystem is PRIME-centric, or you need maximum raw data throughput on CENELEC A band
- Choose G3-PLC if: you need self-healing mesh, native IPv6 addressability, or you are deploying in Asia-Pacific where the G3 ecosystem is strongest
- Both: converging on DLMS/COSEM as the application layer — so HES integration is similar regardless of PLC choice
Further Reading
- PRIME Alliance: prime-alliance.org
- G3-PLC Alliance: g3-plc.com
- ITU-T G.9902 (PRIME v1.3), G.9903 (G3-PLC), G.9904 (PRIME v1.4)
- IEC 62056-7-5: DLMS transport over PLC networks