Battle for adoption
As the demand for worldwide IoT rapidly rises, so does the need for low power, low-cost and low throughput cellular devices. CAT-M and NB-IoT, the two cellular technologies leading the cellular IoT era, are competing for position and adoption around the world.
When carriers consider which cellular technology to supply, the decision entails more than just determining which option is most suitable to their region’s application needs. Carriers also seek out the technology that satisfies the market’s demand for both a low-cost and power efficient solution – universally the two most attractive features to consumers.
So what is the current situation? Where does the industry stand on these two technologies?
CAT-M vs. NB-IoTNBN
CAT-M and NB-IoT share several crucial beneficial elements over other existing technologies. Both offer a low-cost technology solution and differ in total cost by very little. This cost difference is mainly a result of the processing power required by the application, and the memory required by the application running on top of the LTE technology.
Additionally, both technologies allow a special hardware design that supports most commercial LTE bands with the same hardware SKUs (Stock Keeping Units). This enables all operators around the world to be supported by the same exact hardware, which avoids the overhead of separate SKUs. Altering the band and LTE technology (between CAT-M and NB-IoT) can all be done via software, which allows for better management and coverage.
While both CAT-M and NB-IoT are the leading cellular technologies for IoT and pose similar benefits, they each provide a unique user experience. The differences can be characterized based on the functionality of some key technology features:
| CAT-M | NB-IoT | |
| Data Rate | ~300 Kbps | ~50Kbps |
| Bandwidth | 1.4 MHz | 200 KHz
|
| Power Consumption | Best at higher data rates (100s of bytes/message) | Best at low data rates (10s of bytes/ message)
|
| Latency | This comparison is dependent on use-case, coverage and other factors. Generally, CAT-M latency is orders of magnitude less than NB-IoT, with NB-IoT target latency defined as < 10 seconds
|
|
| Mobility | Full mobility support | No connected mobility
|
| Voice | Yes | No |
In general, NB-IoT is the preferred technology for simple sensor and metering applications, transmitting in short bursts, such as in street lighting and periodic utility readings, among others. CAT-M applications enable additional and more demanding requirements, such as asset tracking, real-time actuation of industrial controllers, among others. This is also enabled by better power consumption for reachable devices, better FOTA support and lower latency. Moreover, CAT-M is the only LPWA technology supporting voice applications.
However, while each technology has its pros and cons, the ultimate decision will usually boil down to local coverage. Let’s take a look at how operators in various geographies are implementing these two technologies, based on initial market availability and maturity, and competitive dynamics.
Global rollout
Currently, the largest carriers in the U.S., China, Europe, Japan and Korea support either CAT-M or NB-IoT. It is expected that operators who exclusively started with NB-IoT will incorporate CAT-M technology within the next two years to leverage some of the maturity features of CAT-M that were created by U.S.-based operators. We also see that operators who started with CAT-M will add NB-IoT to their networks.
The two largest networks in North America, Verizon and AT&T, currently support CAT-M only. Initially, the decision to support CAT-M was driven by its ability to support a wider range of applications, earlier standardization in 3GPP, and its requirement for simpler infrastructure changes. However, since most current infrastructure vendors already support both technologies, North American operators are expected to integrate NB-IoT and adopt the dual-mode concept within the next two years. Additional leading operators in other regions, including Europe, Japan and Australia, are demonstrating similar integration trends as well.
Dual-mode operation
The increasing global demand for integrated CAT-M and NB-IoT chipsets poses several valuable benefits for carriers to support dual-mode operation. Specifically, since dual-mode operation is required by key IoT applications and device manufacturers, integrated chipsets offer substantial commercial value and present profitable market opportunities.
Today, many vendors offer either CAT-M or NB-IoT, targeting their solutions to a specific geography or catering to a specific operator. However, this approach should be modified since the majority of customers are original equipment manufacturers and cannot be segmented by geographical location or operator. OEMs, which ship their devices in volume, target the global market where there is a much more wide variety of CAT-M and NB-IoT coverage demands that need to be met. For this reason, offering both technologies provides logistical and commercial advantages. Indeed, vendors would benefit from selling a device that supports dual-mode operation – one that meets any CAT-M or NB-IoT scenario and is suitable for global distribution.
Similarly, dual-mode operation would be a valuable feature in global roaming devices and applications, such as trackers and smartwatches. Roaming devices that start out in an NB-IoT network have the potential to end up in a CAT-M network. The OneSKU feature is a simple solution to this issue.
Since the same hardware is shared between CAT-M and NB-IoT, the band and LTE technology can be selected via software, which removes the need to run separate SKUs whenever the roaming device or application is used in a different geographical region.
In addition to commercial advantages, there are many use cases that present application-related value for dual-mode operation as well. For example, when an operator is ready to upgrade the firmware of a device that operates on an NB-IoT network, it would be more efficient to design the device to switch to a CAT-M network as this will significantly conserve battery power. Once the upgrade is complete, then the network should be switched back to NB-IoT to resume the device’s normal functionality.
Next generation of cellular IoT
The IoT industry is moving quickly as major providers strive towards the next generation of cellular IoT. The adoption of CAT-M and NB-IoT is creating a new global market for IoT devices and applications — and the demand for a truly end-to-end LTE network solution.
The mature ecosystems of CAT-M and NB-IoT around the world are rapidly overtaking market share of non-LTE technologies and are demonstrating promising market potential for dual-mode devices. It will be interesting to track how dual-mode technologies continue to take center stage over the next 12 months and further propel the ever-growing IoT market.
In the very near future, selection of CAT-M vs. NB-IoT will no longer just be a function of geographical location. Dual-mode solutions will create a new wave of full integration, unlocking even more opportunities for consumer, commercial and industrial IoT services.
Ilan Reingold serves as VP Business Development and Marketing at Altair Semiconductor, a subsidiary of Sony Corporation and a leading provider of LTE chipsets. Altair has shipped millions of LTE chipsets to date, commercially deployed on the world’s most advanced LTE networks including Verizon Wireless, AT&T, Softbank and KT (Korea Telecom). For more information, visit: www.altair-semi.com
