Cat-1bis and the Future of IoT Cellular Connectivity

Cat-1bis has emerged as a viable and interesting option for IoT use cases, primarily due the the increasing demand for low-power, high-speed, and cost-effective connectivity solutions. Among the cellular technologies available, Cat-1bis has advantages when compared to incumbent solutions in the market such as Cat-1 or even Cat-M1. In this blog post, we’ll explore the advantages of Cat-1bis over other popular cellular options for IoT designs.

What is Cat-1bis?

Cat-1bis is a newer category of 4G LTE, and to an extent is also considered part of 5G, that has been introduced into the IoT landscape. Cat-1bis is revision, or modernization of the original LTE category 1 – as “bis” means “the second”. Cat-1bis does everything the original version does and adds new features specified in more recent versions of the 3GPP standard. Notable differences include support for low-power modes, such as eDRX and PSM, which allow the radio to go to a very low-power sleep mode for seconds or minutes at a time to save power while remaining “connected” to the network, allowing for incoming SMS, voice or data, with a delay related to the sleep time. It also removes the need for a diversity RX antenna and instead requires only a single antenna for both TX/RX, which can be a major space savings in a small device vs Cat-1 or higher radios which require at least two antennas.

The other major factor for comparison is coverage. Unlike Cat-M1 or NBIoT (NB1/2), Cat-1 and higher radios, including Cat-1bis, use the exact same frequency allocations and base station systems as regular smartphones. M1 and NB have advantages of unit cost for the hardware but they require each tower to be specifically configured to support their functionality. This “coverage parity”, while long claimed by the US MNOs, still isn’t complete. Cat-1 radios are also faster for applications that need more than the 1 mbps of M1 or hundreds of kbps of NB. Cat-1 is 10 mbps

Key Advantages of Cat-1bis for IoT

1. Cost-effectiveness: Compared to higher order LTE categories, Cat-1bis cost less. The solution only requires a single antenna and receiver. It offers a cost-optimized solution for IoT applications that require medium-bandwidth connectivity.
2. Global coverage: Relative to LTE Cat-M or NB-IoT, Cat-1bis offers superior global coverage. This makes it best-suited for IoT applications that require worldwide connectivity.
3. Fast, low-latency data transfer: Cat-1bis offers faster, lower latency, data transfer rates compared to Cat-M. This makes it perfect for IoT applications that require real-time data transfer, such as medical devices, smart grid, or automotive applications.
4. Power efficiency: Cat-1bis is designed to be power-efficient, which is ideal for battery-powered IoT devices. Newer Cat-1bis modules can take advantage of fundamental power saving features of the LTE standard including power save mode (PSM) and extended discontinuous reception (eDRX).

Cat-1bis offers several advantages over other cellular technologies that make it ideally suited for IoT applications. This shows up in our customers choosing Cat-1bis for new developments over M1 and NB radios.
To get a little more detail, check out this blog post from Qualcomm on Cat-1bis.