Cat-1bis Needs Differentiating Features to Avoid a Race to the Bottom

In June 2024, cellular module manufacturers u-blox and Cavli Wireless bolstered their LTE Cat-1bis module portfolios, with new models supporting additional features to target power saving in Internet of Things (IoT) devices. Cavli Wireless launched the C17QS, which is an enhancement to its earlier C16QS design originally released in January 2023. Swiss vendor u-blox launched the LEXI-R10 and SARA-R10, augmenting its LENA-R8 Cat-1bis module series, which first came to market in January 2022.

Each new product provides additional features, many of which have not previously been included in Cat-1bis modules. The most notable feature is support for Extended Discontinuous Reception (eDRX), which optimizes sleep time when a connected device is in an inactive state. Originally developed for use with the Low Power Wide Area (LPWA) technologies Cat-M and Narrowband IoT (NB-IoT), many IoT industry observers are unaware of the potential to support eDRX over Cat-1bis as well.

Cellular modules are the most common path to enabling connectivity in IoT devices, and can include additional features to enhance that role. Value-added hardware features already include support for the Short Range Wireless (SRW) technologies Wi-Fi, and Bluetooth®, as well as Bluetooth® Low Energy (LE). More recently, modules have included support for Wi-Fi Scan, which provides additional location-based data for mobile assets.

Massive Machine-Type Communications (mMTC) is a core service area for 5G networks, wherein a very large number of devices are connected to a single base station, with a long battery life, and at long range. This necessitates a simplified device architecture that consumes as little power as possible. As a User Equipment (UE) standard, Cat-1bis is a primer for mMTC, touted by some semiconductor manufacturers as the best migration path to 5G for the IoT. Cat-1bis reduces the complexity of Cat-1 by decreasing the number of receive antennas required from two to one. The result is simplified and cheaper hardware that consumes less power, while still supporting native Cat-1 data rates of 10/5 Megabits per Second (Mbps) Downlink (DL) and Uplink (UL), respectively.

The growing use of Cat-1bis in asset tracking, metering, and telematics is rooted in the need for higher throughput than LTE-M and NB-IoT, while in the case of asset tracking also minimizing power consumption. Cavli Wireless’ and u-blox’s new Cat-1bis modules are some of the first known to support eDRX. For implementers of IoT systems, eDRX enables a higher level of precision when defining the conditions by which an IoT device is in sleep mode, how long that device stays asleep, and when it is reachable in receive mode. By providing greater customization over these intervals, device Original Equipment Manufacturers (OEMs) can optimize their equipment to minimize power consumption and maximize battery life.

The inclusion of eDRX in the C17QS, LEXI-R10, and SARA-R10 modules brings to light some emerging trends in the Cat-1bis module market. The first is device manufacturers’ clear requirements for improved power optimization. According to u-blox, the SARA-R10 “is ideally suited to a wide range of value-oriented applications that require medium data speed, global coverage, and positioning, [with typical applications being] asset tracking, telematics, healthcare and payment & vending.” Many devices within these segments are likely to remain dormant for much of their life, but still require higher throughput than Cat-M and NB-IoT. As a result, eDRX is likely to be of high value for manufacturers that want to reduce energy consumption for as long as possible.

Second is product differentiation. Since 2022, competition has ramped up with MeiG Smart, Quectel, and SIMCom from China, plus Sequans, Telit Cinterion, and Sierra Wireless launching Cat-1bis modules. The inclusion of additional value-added features such as eDRX provides another layer of differentiation as competition continues to grow. In November 2023, Sierra Wireless launched its RC7110 module, powered by the Qualcomm QCX216 chipset, which included support for eDRX, with u-blox and Cavli now following that approach. With additional power savings seemingly becoming a core issue for device OEMs, it is likely that other module vendors will do the same to deter customers from switching providers.

With more value-added features emerging, module vendors with existing Cat-1bis module lines should consider support for eDRX as a way of enabling further power savings for their customers, and to diversify their module offerings. In IoT market segments where the lowest possible power consumption is vital, eDRX-enabled modules are likely to be in-demand, and may enable a marginal increase in selling price. Indeed, any battery-powered IoT device, including those that will be regularly recharged, will benefit from being more energy efficient, by being able to do more work on a single charge.

Rather than imitating this approach, some may question the wisdom of supporting a technology that was principally developed for LTE Cat-M and NB-IoT. According to some semiconductor manufacturers, there is a 5X improvement in power savings from running eDRX over Cat-M compared to Cat-1. Module vendors will need to calculate the relative power and cost savings of prospective Cat-1bis modules with eDRX support, and collaborate with their device OEM customers to gauge interest. Vendors that opt against support for eDRX may choose to develop Cat-1bis modules with more distinctive technology bundles. For example, vendors may look at Embedded Subscriber Identity Module (eSIM) and Wi-Fi Scan, which are known to have been supported in recent Cat-1bis module launches.

The recently standardized Enhanced Reduced Capability (eRedCap) will eventually replace Cat-1bis once Long Term Evolution (LTE) networks are phased out. eDRX is included in the Release 18 standards for eRedCap, meaning that module vendors may prefer to support eDRX in their Cat-1bis modules now to provide a natural design path from LTE to eRedCap. The first chipsets for eRedCap are expected to arrive in 2026, and vendors should start aligning their design roadmaps with their commercial availability, given that this will be a hyper-competitive space. eRedCap will outlive Cat-1bis, making it a more strategic investment. The Cat-1bis window of opportunity may be shorter, but will still be intensely contested. The most trusted and capable Cat-1bis module suppliers are likely to be a device OEM’s first choice for eRedCap, too; finalizing an innovative Cat-1bis strategy now may pay dividends for module vendors beyond the life span of 4G.