The next-generation smart meter gateway: LTE-450 and WAN connectivity

What defines the new SMGW generation

New generation is an industry term, not a standard. There is no official SMGW 2.0 norm. What people mean are devices that can do more than the first smart meter gateways, both on the tariff side and on the radio link. The step up comes from extended re-certification rather than from a new specification, so much of it lands on existing hardware as a firmware update rather than as a replacement.

Two shifts mark the difference. On the tariff side the number of normatively available tariff use cases (TAF) grew from four to seven. The first generation could do TAF 1, 2, 6 and 7, and the grid-supportive TAF 9 and 10 plus the high-frequency TAF 14 were added later. On the radio side additional WAN technologies arrived, above all the dedicated 450 MHz network LTE-450 for critical infrastructure. Both are about the device reaching more use cases and more sites.

• Not a standard: there is no official SMGW 2.0, only extended re-certification.
• From four to seven TAF: the normatively available tariff use cases grew.
• Additional WAN technologies: above all LTE-450 for critical infrastructure.
• Basis stays the same: BSI TR-03109-1, installation under v1.1 until the end of 2027, certification under v2.0 with TAF 8 and 15 from 2027.

The basis remains the BSI technical guideline TR-03109-1. Gateways under version 1.1 may still be installed until 31 December 2027. Version 2.0 of 13 December 2024 sets the new state of the art, and from 1 January 2027 certifications under it must also meet the requirements marked MUSS+, including TAF 8, TAF 15 and a unified WAN interface. So the new generation is not a clean break but an expanded capability set on the same regulatory foundation, which is exactly why so much of it can reach the field by re-certification rather than by new hardware.

The tariff use cases in brief

Tariff use cases (TAF) are the rule sets with which the smart meter gateway records metered values, processes them and sends them to authorised recipients. They decide which tariffs and which services are technically possible. The handbook chapter on tariff use cases explains every TAF from 1 to 16 with its name, function and status in versions 1.1 and 2.0 of the guideline. This article keeps to what matters for the device and its connection.

The original catalogue of BSI TR-03109-1 ran from TAF 1 to TAF 14. Since version 1.1 of 17 September 2021 only seven remain, all of them mandatory: TAF 1, 2, 6 and 7 for billing and balancing, TAF 9 for the actual feed-in of generation plants, TAF 10 for grid state data and TAF 14 for high-frequency values. BSI took the other numbers out of the guideline with that version.

Version 2.0 of 13 December 2024 replaces TAF 6 with a general on-demand function. For certifications from 1 January 2027 it also requires a redefined TAF 8, load profile formation with maximum values, and the new TAF 15 for readings from registering meters. In mid-October 2026 BSI listed no gateway certified under version 2.0. Every certificate of the five manufacturers is based on version 1.1.

And TAF 5 and 16? A BSI implementation note of 16 September 2025 describes event-based tariffing as TAF 5 and event-based registration as the new TAF 16. It isn't binding. A gateway may implement these cases but does not have to.

Which TAF is actually active at a metering point depends on the device, its certification and the evaluation profile the gateway administrator installs. For dynamic tariffs, TAF 7 is what matters, as the next section shows.

How dynamic tariffs run via the SMGW

Dynamic tariffs have been mandatory since 2025. Technically they do not need the most exotic TAF but the metered load profile, and getting that right avoids a common misconception.

Since 1 January 2025 every electricity supplier must offer at least one dynamic tariff under Section 41a EnWG. The technical basis is TAF 7 with its 15-minute values, complemented by TAF 2 for time-variable models. TAF 14, the high-frequency use case, serves visualisation and value-added services, not billing. And the precondition on the customer side is a smart metering system, not a simple modern meter. For the price logic and the market mechanics behind these contracts, the article on dynamic tariffs goes deeper.

• Mandatory since 1 Jan 2025: all suppliers, under Section 41a EnWG.
• Technical basis: TAF 7 with 15-minute values, complemented by TAF 2.
• TAF 14: for visualisation and value-added services, not for billing.
• Precondition: a smart metering system at the customer.

The practical upshot is that a supplier does not need every TAF to launch a dynamic tariff. It needs TAF 7 and TAF 2 in the gateway and a smart metering system at the meter point. The high-frequency reading is a nice add-on for an app, but the bill is built on the 15-minute metered load profile.

WAN technologies: LTE, LTE-450 and powerline

The biggest practical hurdle is reachability. Around a quarter of meter points sit where radio is difficult, so the right WAN choice often decides whether a gateway works at all.

At the WAN side the gateway can use several technologies. The mobile network covers most sites via LTE or GPRS. Broadband powerline per IEEE 1901 carries data over the power line itself, and ethernet or fibre serves sites with a fixed line. New in the ramp-up is LTE-450, a dedicated 450 MHz network for critical infrastructure. Its advantages are physical: better building penetration than ordinary mobile bands and 72 hours of backup power at all network elements, which keeps it reachable in a power outage. For radio-less basement locations, powerline and hybrid solutions bridge the gap where no signal reaches.

• Mobile network: LTE and GPRS for the majority of sites.
• Broadband powerline: per IEEE 1901, over the power line itself.
• Ethernet or fibre: for sites with a fixed connection.
• LTE-450: the dedicated 450 MHz network, better building penetration, 72 hours of backup power.

The point is that there is no single best radio. The gateway picks the technology that fits the site, and LTE-450 is the answer where ordinary mobile fails, above all in basements and at critical infrastructure that must stay reachable through an outage. Powerline closes the remaining gaps so that the radio-less quarter of meter points still reports back.

Outlook: LTE-450, new TAF and the ramp-up

The development goes on. New tariff use cases and the LTE-450 build-out shape the next stage, while the rollout itself still has a long way to run.

The next binding step on the tariff side is TAF 8 and the new TAF 15, which certifications under version 2.0 must cover from 1 January 2027. Beyond that, a non-binding BSI implementation note of 16 September 2025 describes the event-based TAF 5 and TAF 16. On the radio side, 450connect reports that LTE-450 coverage rose from 34 percent in early 2025 to around 90 percent in October 2025, with more than 10,000 gateways active in the 450 MHz network by the end of that month. In August 2026 it reported 100,000 active SIM cards across all device types, without a separate figure for smart meter gateways. The rollout overall remains early: by 30 June 2026, 3,172,579 of 54,135,202 metering points had a smart metering system, 5.9 percent. On 21 September 2026 the Federal Network Agency (BNetzA) corrected the earlier figure of around 3.09 million for the end of 2025 to 2,406,454, or 4.4 percent, because of double counting. The neighbouring articles set the wider frame, on the backend side in the piece on scaling the SMGW backend and on the home area network side in EEBUS and IEC 63380.

• TAF 8, 15, 5 and 16: TAF 8 and 15 are binding for certifications from 2027, the event-based TAF 5 and 16 are described in a non-binding BSI note of September 2025.
• LTE-450 coverage: up from 34 percent in early 2025 to around 90 percent in October 2025, per 450connect.
• In the 450 MHz network: more than 10,000 gateways active by the end of October 2025, and 100,000 active SIM cards across all device types in August 2026.
• Rollout status: 3.17 million smart metering systems by 30 June 2026; the end-2025 figure was corrected to 2.41 million.

The picture is one of capability racing ahead of installed base. The framework can already do far more than most meter points use, and the gap between what the device supports and what is in the field is where the next years of work sit. Whoever plans for TAF 8 and 15 now and keeps an eye on TAF 5 and 16 buys headroom for later.

What companies should do now

Whoever plans the WAN strategy per site and lifts existing devices by firmware gets the maximum out of the technology already in place. Dynamic tariffs build on TAF 7.

• Set the WAN strategy per site. Decide between LTE, LTE-450, powerline and ethernet per location rather than rolling out one technology everywhere.
• Plan LTE-450 for hard-to-reach sites. Reserve the dedicated 450 MHz link for basements and critical infrastructure that must stay reachable in an outage.
• Upgrade existing devices by firmware. Lift the installed base to TAF 9, 10 and 14 by re-certification instead of replacing hardware.
• Base dynamic tariffs on TAF 7. Build the tariff logic on the 15-minute metered load profile, plan TAF 8 and TAF 15 for devices certified from 2027 and keep an eye on the BSI note on TAF 5 and 16.

Further reading

Frequently asked questions