4G vs 5G Industrial Router: Which Suits Your Plant in India

For PLC and SCADA telemetry (tag values, alarms, remote diagnostics) a 4G LTE industrial router with dual SIM failover is usually enough, because the data is small and LTE coverage is wider.

Choose 5G when you have a measured need for high bandwidth (several camera streams, large file transfers) or lower latency, and you have tested 5G signal at the exact panel location on more than one operator.

Whatever you buy for use in India, check its TEC MTCTE certification status.

Who this is for: plant engineers and IT/OT teams choosing a cellular router for remote monitoring of PLCs, SCADA nodes, pump stations, DG sets or solar sites.

Start with the data, not the radio

Estimate what you actually send. A worked example (illustrative):

• 300 tags, each a 4 byte value plus about 50 bytes of protocol overhead, sent every 10 s
• 300 × 54 bytes = 16.2 kB per update, 8,640 updates per day
• About 140 MB per day, roughly 4.2 GB per month, before compression or report by exception

Even this generous case is a small, steady stream, well within LTE uplink capability. Report by exception (send only on change, as MQTT and many SCADA protocols support) can cut it further.

One 1080p stream, by contrast, typically needs several Mbit/s continuously (the YouTube encoding guide recommends 8 Mbit/s for 1080p at 30 fps; H.265 CCTV streams are often lower, so check the camera) (YouTube recommended upload encoding settings).

That is where bandwidth starts to matter.

Measure your own: most routers show data counters. Run a pilot for a week and look at the monthly total and peak.

What 4G gives you

• Coverage: LTE networks in India are much wider than 5G, especially in industrial estates outside city centres. Check operator coverage maps, then test at site.
• Bandwidth: LTE category (Cat 1, Cat 4, Cat 6 and above) sets peak rates; for telemetry even Cat 1 is often enough. Categories are defined by 3GPP in TS 36.306 (3GPP specifications).
• Power and heat: 4G modules generally draw less than 5G modules, which helps in sealed panels and solar powered sites. Compare datasheet figures for the exact models.
• Cost: 4G routers and plans are generally cheaper. We do not quote prices here.

What 5G adds

5G NR is specified by 3GPP from Release 15 onward (3GPP Release 15). For a plant router it can add:

• Higher uplink and downlink throughput, useful for video, large log uploads or remote desktop to many HMIs
• Lower air interface latency, which helps interactive remote work. End to end latency over public networks still depends on the core network and internet path
• Release 17 introduced reduced capability (RedCap) devices for mid range IoT (3GPP Release 17); check operator support before relying on it

What it does not do: make a closed loop control link over a public network safe. Keep control in the PLC; use cellular for supervision and data.

Most 5G routers fall back to 4G when 5G is not available. Confirm the fallback bands too.

Coverage is the deciding factor

Plants are hard RF places: steel sheds, concrete, panels inside panels. Before you buy:

1. Use a phone or a test router at the panel location, not at the gate.
2. Record signal values (RSRP, RSRQ, SINR) for each operator, for 4G and 5G. These are defined in 3GPP TS 36.214 for LTE and TS 38.215 for NR.
3. Test at different times of day.
4. If signal is weak inside, plan an external antenna on the roof with low loss cable. Antenna gain does not fix a dead site.

Check which bands each operator uses in your area and that the router supports them. India’s spectrum assignments are published by DoT (Department of Telecommunications).

Dual SIM failover

For telemetry, reliability usually matters more than speed. Dual SIM lets the router switch to a second operator when the first fails. Ask:

• Is it dual SIM single standby (one active at a time, switch on failure) or dual modem (both active)? Single standby is common and cheaper; switching takes time.
• What triggers failover: loss of registration only, or a failed ping to a set host? Ping based checks catch more real failures.
• Does it fail back to the primary SIM, and when?
• Does the VPN reconnect automatically after a switch?

Pair it with local buffering at the gateway or PLC so data during an outage is sent later, not lost.

Security basics

Whatever the radio, follow the same rules as any remote access to control systems:

• No open ports from the internet to PLCs or HMIs. Use a VPN or an outbound only broker connection.
• Private APN from the operator if available.
• Change default passwords, keep firmware updated, turn off unused services.
• Log remote sessions.

CISA’s primary mitigations for operational technology say to remove OT connections to the public internet and, where remote access is needed, use a private network or VPN with phishing-resistant multi-factor authentication (CISA, Primary Mitigations for OT). The IEC 62443 series is the reference for zones and conduits (ISA/IEC 62443).

India buyer check: TEC MTCTE

Under the Indian Telegraph (Amendment) Rules 2017, the Telecommunication Engineering Centre (TEC) runs the Mandatory Testing and Certification of Telecom Equipment (MTCTE) scheme.

The TEC notice dated 1 July 2024 (Annexure-I) lists Routers under Phase IV, mandatory from 1 August 2024, and IoT Gateway under Phase III, mandatory from 1 January 2024.

There is no separate cellular router category, so ask the seller which category their model is certified under (TEC MTCTE notice). Ask the seller for the MTCTE certificate number for the exact model and check it on the TEC portal (tec.gov.in).

Also ask whether a WPC Equipment Type Approval (ETA) applies to the radio in that model (DoT).

Side by side

If your need is small Modbus telemetry over 4G rather than a general purpose router, see our 4G Ethernet Modbus gateway with Wi-Fi page for its 4G SIM, Wi-Fi and Ethernet options.