It’s been about two years since 3GPP, the Standards Developing Organization that defines mobile communication standards, froze its 14th release. The release includes a number of improvements to NB‑IoT and LTE‑M, two cellular technologies that enable the cellular Internet of Things. Now that many of the features are supported by mobile network operators, cellular module manufacturers are announcing the first generation of Release 14 compliant low power wide area cellular modems.
Defined in 3GPP Release 13, NB‑IoT (also referred to as LTE Cat NB1) and LTE‑M (LTE Cat M1 or eMTC) are optimised to communicate small amounts of infrequent data with minimal power consumption and maximum coverage – common requirements in IoT applications, from fleet management and asset tracking in logistics to smart parking and water and gas monitoring in smart cities. With 3GPP Release 14, NB‑IoT and LTE‑M transfer data faster (at higher data rates) while consuming less power.
NB‑IoT and LTE‑M cellular modems designed to meet all 3GPP Release 14 features can also be referred to as LTE Cat NB2 and LTE Cat M2 modems.
Here are some of the enhancements that 3GPP Release 14 brings to LPWA modems:
Even lower power consumption for NB‑IoT
From day one, NB‑IoT was designed to enable battery‑powered IoT devices offering up to a decade of connectivity on a single battery. 3GPP Release 14 introduces a new, lower power class for NB‑IoT. Tailored to the needs of modems powered by small batteries, it allows devices to transmit messages with a maximum transmit power of 14dBm. This translates into more relaxed requirements on the external battery, which no longer needs to deliver the high current spikes typical for transmissions at 23dBm.
The new specs also increase the size of the transport blocks. This means that data can be broken down into larger data packages, reducing the time needed to send transmit a given amount of data. Reduced transmission time directly translates into reduced power consumption.
As a result, battery‑powered IoT devices such as smoke detectors, smart meters, and other distributed sensors can run for longer, requiring less maintenance.
Even better cell capacity
To increase the number of IoT devices that can operate within a single network cell, 3GPP Release 14 brings enhancements in the cell capacity and usage of NB‑IoT network resources via two features called Non‑Anchor Paging and Non‑Anchor Random Access Procedure (RACH). These are extremely useful in smart home and connected buildings applications, where the density of IoT devices is expected to increase enormously in the coming years.
Higher data rates
Under Release 14, LTE‑M significantly increases data rates by expanding data packet sizes almost threefold. With peak data rates around 4Mbps in DL and 7Mbps in UL at a bandwidth of 5MHz, LTE‑M becomes an interesting technology for a greater range of applications that require greater data throughput or lower latency, like in smart cities and remote monitoring devices.
Improved mobility for NB‑IoT
Release 14 brings RRC Connection re‑establishment to NB‑IoT devices, allowing modems to move from one network cell to another without having to renegotiate a new connection. Not only does this deliver continuous communication for mobile applications, it also reduces overhead data, with subsequent reductions in power consumption.
NB‑IoT then becomes a more obvious and cost‑effective choice for tracking of assets that do not require rapid exchange of location information (which would still be restricted by the lower data rates). For example, it is ideal for tracking construction equipment that may spend some time at a given job site before being relocated to another.
Improved LTE‑based positioning
This improvement comes with a disclaimer: while 3GPP Release 14 improves attainable positioning accuracies using LTE‑M and NB‑IoT network infrastructure, this is a feature that needs to be implemented by mobile network. Once implemented, however, modems will be able to use Enhanced Cell‑ID (E‑CID) and Observed Time Difference of Arrival (OTDOA) positioning methods.
Because the attainable accuracies depend on the configuration of nearby cellular base stations, this enhancement will reliably deliver course positioning estimates. A common application is asset tracking.
Another step on the road to 5G
3GPP Release 14 is another stepping stone on the road to 5G, paving the way for low power wide area technologies that will be part of the next generation of mobile network technology, enabling IoT device makers to bring products to market today that will be able to support the network technologies of tomorrow.
Guest blog written by Samuele Falcomer, Product Management Cellular, u‑blox Italy.