LTE Cat 1 bis: The Complete Guide to the Standard Replacing 2G, 3G and Cat 1

What is LTE Cat 1 bis?

LTE Cat 1 bis is a 4G cellular standard for the Internet of Things that delivers the same performance as LTE Cat 1 while using a single antenna instead of two. It was formally specified by 3GPP in Release 13 in 2016, runs on existing LTE networks with no infrastructure changes, and offers peak speeds of 10 Mbps downlink and 5 Mbps uplink with latency below 100 ms.

That single-antenna design is the whole point. Removing the second receive antenna shrinks the board, simplifies RF layout and cuts the bill of materials, which makes Cat 1 bis a natural fit for compact, cost-sensitive devices that still need real broadband-class throughput rather than the trickle offered by low-power standards.

Because it is built on standard LTE rather than a specialised profile, Cat 1 bis inherits the same global network availability, roaming and mobility as any other LTE device. For anyone migrating away from retiring 2G and 3G networks, that combination of broad coverage, mature ecosystem and modest data rates is why Cat 1 bis has moved from niche to mainstream.

Cat 1 bis vs Cat 1: the single-antenna difference

The original LTE Cat 1 standard arrived in 3GPP Release 8 in 2008 as the first LTE variant aimed squarely at IoT. It performed well, but its two-antenna requirement was awkward for small devices such as trackers, wearables and metering endpoints, where a second antenna adds cost, components and precious board space.

Release 8 never clearly stated whether a single-antenna Cat 1 device was compliant, which left designers guessing. 3GPP settled the question in Release 13 by defining Cat 1 bis: a standard that explicitly permits a single receive antenna while preserving Cat 1’s throughput, latency, roaming and robustness. Crucially, a Cat 1 bis device requires no special signalling and connects to existing Cat 1 networks worldwide.

In short, Cat 1 bis gives you the same connectivity as Cat 1 in a smaller, cheaper package. For new designs there is rarely a reason to choose classic two-antenna Cat 1 over Cat 1 bis.

Technical specifications at a glance

Cat 1 bis vs LTE-M vs NB-IoT: how to choose

Cat 1 bis sits in the sweet spot between full-fat LTE and the low-power wide-area (LPWA) standards. LTE-M and NB-IoT win on power draw and deep-indoor penetration but cap out at low throughput. Cat 1 bis trades a little battery life and a slightly higher module cost for genuine broadband-class speed, full mobility and voice. The right choice comes down to how much data you move and how you move it.

Power efficiency: PSM, eDRX and the ON-time advantage

Cat 1 bis supports the same two power-saving mechanisms as the LPWA standards. Power Saving Mode (PSM) lets a device register on the network then go into a deep sleep for hours or days while remaining attached, and extended Discontinuous Reception (eDRX) lengthens the interval between paging checks. Together they let field devices such as meters and trackers sit dormant almost all the time and wake only to transact.

There is a subtler efficiency advantage too. Because Cat 1 bis moves data far faster than NB-IoT or LTE-M, it spends less time in active mode to send the same payload. A transaction that keeps an NB-IoT radio awake for hundreds of milliseconds can be completed by a Cat 1 bis radio in single-digit milliseconds. Shorter active windows mean less energy burned per message, which narrows the battery-life gap for duty-cycled applications that report periodically rather than stream continuously.

Why Cat 1 bis is booming: the 2G and 3G sunset

The single biggest driver behind Cat 1 bis adoption is the worldwide retirement of legacy networks. As operators refarm 2G and 3G spectrum for 4G and 5G, millions of established M2M applications built on GPRS and 3G modules need a migration path. Those applications typically need more than a sensor trickle but less than full LTE, which is exactly the band Cat 1 bis occupies.

Cat 1 bis is attractive as a replacement because it runs on the LTE networks operators are keeping, offers global availability, and drops into device designs with minimal RF rework thanks to its single antenna. The result is a fast-growing installed base rather than a speculative one.

Analyst forecasts reflect the shift. ABI Research has projected that Cat 1 bis will take over the majority of the Cat 1 market by the end of the decade, and firms including IoT Analytics expect double-digit annual growth for the category. For product teams, that momentum matters: it signals a deep, competitive module ecosystem and long-term operator support.

Applications and industries

Cat 1 bis suits any use case that needs dependable, mobile, mid-rate connectivity on global LTE. Common deployments include:

• Asset and vehicle tracking – GNSS-enabled trackers that need mobility, handover and periodic data upload.
• Smart metering – electricity, gas and water meters replacing 2G endpoints, where firmware updates and moderate payloads rule out NB-IoT alone.
• Payment and point of sale – card terminals needing low latency, reliability and roaming.
• Telehealth and connected medical devices – portable monitors transmitting richer data sets.
• Security and alarm systems – panels and cameras needing image transfer and voice.
• Micromobility and fleet – e-bikes, scooters and shared vehicles with continuous location reporting.
• Industrial and smart-city sensing – gateways aggregating data where LPWA throughput falls short.

The Cat 1 bis module landscape

Cat 1 bis is a mature, multi-vendor market rather than a single-supplier technology. Most major cellular module makers ship Cat 1 bis parts, frequently with integrated eSIM and GNSS, in region-specific band variants for EMEA, North America and global deployment. Because the standard is uniform, the practical differences between modules come down to band support, positioning options, integrated SIM and eSIM choices, certification coverage, form factor and the surrounding connectivity or device-management platform.

When you evaluate modules, look past the raw radio spec and weigh the total package: does it cover the bands and regions you ship to, does it offer the GNSS constellations you need, is eSIM or eUICC available for freedom to switch operators, and what management tooling ships alongside it. Those factors, not the LTE category itself, are what separate one Cat 1 bis product from another.

Frequently asked questions

Is LTE Cat 1 bis the same as Cat 1?

Almost. Cat 1 bis delivers identical throughput, latency, mobility and roaming to Cat 1, but uses a single antenna instead of two. It is best understood as a refined, more compact and lower-cost version of Cat 1 that runs on the same networks.

Which 3GPP release defined Cat 1 bis?

3GPP Release 13, finalised in 2016. Some materials incorrectly cite Release 14; the standard was defined in Release 13.

Is Cat 1 bis an LPWA technology?

Not strictly. It is a full LTE standard that is often compared with LPWA options because it targets IoT. It offers far higher data rates than NB-IoT and LTE-M, at the cost of somewhat higher power consumption and module price.

Does Cat 1 bis support voice?

Yes, it is VoLTE capable where the operator supports it, which makes it suitable for alarm panels, intercoms and similar voice-enabled devices.

Will Cat 1 bis work after 2G and 3G shutdown?

Yes. Cat 1 bis runs on 4G LTE networks that operators are retaining and expanding, which is precisely why it is a leading migration path away from sunsetting 2G and 3G.

Should I choose Cat 1 bis or NB-IoT?

Choose Cat 1 bis if you need real throughput, mobility, voice, firmware over the air or reliable roaming. Choose NB-IoT if you have static, ultra-low-data devices where multi-year battery life and deep-indoor coverage matter most.

The bottom line

LTE Cat 1 bis has earned its place as the pragmatic middle ground of cellular IoT. It keeps the performance, mobility and global reach of Cat 1, sheds an antenna to cut cost and size, runs on the LTE networks operators are keeping, and supports eSIM for long-term flexibility. With 2G and 3G disappearing and analysts pointing to it as the successor to the bulk of the Cat 1 market, it is the safe default for mid-data IoT designs that need more than a sensor whisper but less than a broadband firehose.