To harness the full potential of inter-connected hardware, there is a growing need to be able to send data from anywhere. This blog looks at advanced cellular solutions that handle all the hard work for you.

Why Cellular?

Whilst there are many competing network solutions battling for a slice of the Internet of Things (IoT) connectivity market, cellular has many attractions for wide area communications. Probably the most significant of these is the existing network infrastructure. A cellular based solution also avoids the spectrum ‘free-for-all’ of competing technologies that are rooted in the licence-free ISM bands. Future development of the cellular network is well planned and the imminent roll-out of NB-IoT promises an attractive solution for the low data rate connections that are the life-blood of many IoT devices.

The u-blox Advantage

Of the many cellular options, u-blox offers a particularly attractive solution with its SARA series of modules. These modules use the space-saving, miniature LGA form-factor and employ a common layout, thus providing a simple drop-in solution when you need to update your cellular technology. In addition, the SARA series is available with a wide range of technology and geographical coverage options. This flexibility allows you to choose the optimum SARA unit for both the desired technology and the intended geography.

SARA Series

The SARA modules are divided into four technology categories covering GSM/GPRS, HSPA, NB-IoT and LTE Cat M1/NB1.


Figure 1: u-blox’s SARA module

The SARA-G3 series focus on providing GSM/GPRS service and offer very low power consumption with a standby current of less than 0.9mA. Within the G3 series, the G300 and 310 variants are particularly suited to cost sensitive applications where a simple bit-pipe is all that’s required.

For high-speed and more sophisticated connectivity requirements, the SARA-U2 series offer HSPA service along with 2G fall-back and are available in automotive grade and with ATEX certification for explosive environments. HSPA data rates for the U2 series provide a fast 7.2Mb/s downlink and a 5.76Mb/s uplink. All modules in this series support GNSS inter-connectivity along with the u-blox licence-free AssistNow and CellLocate® positioning aids.

For NarrowBand IoT links, the SARA-N2 series are the world’s first NB-IoT modules and have been developed for ultra-low power consumption to give a battery life of more than 10 years. This makes them ideal for all manner of smart sensors, smart meters and monitoring systems, where their ability to communicate in poor propagation conditions can be invaluable. The N2 series also include facilities to update the firmware over the air so you can update and add new features remotely.

Finally, there are the R4 series units that provide LTE Cat M1/NB1 communications, with USA, N. America only and global options available. This series also offers very low power consumption and OTA firmware updates using µFOTA client/server with the LWM2M protocol.

Easy to Use

All the SARA units are controlled by easy to use AT commands, whilst the security and protocol management is handled in firmware. One other important feature of the SARA units is their easy integration with u-blox GNSS location modules. Mobile products and those in remote locations often have a requirement for locational information so u-blox have designed selected SARA modules for easy integration with their GNSS receivers. When used together, the commands for the navigation unit can be passed via the same link as the SARA’s AT commands. Additionally, the included u-blox firmware enables enhanced location services such as CellLocate®, AssistNow and eCall.

Development tools

One of the benefits of using a well-established manufacturer such as u-blox, is the excellent range of support that’s available through their development kits, software and documentation.

C027 IoT Starter Kit

A good choice when developing a new IoT product is the C027 reference design which provides a complete IoT starter kit. In addition to the selected u-blox cellular module, the kit features a MAX-M8Q GPS/GNSS receiver and a Cortex-M3 microprocessor with Flash and RAM. To simplify the programming, the C027 kit works with the popular mbed online IDE. This gives easy access to a wealth of free code libraries along with simple drag and drop programming. The C027 has a comprehensive set of I/O connections including dedicated Ethernet and CAN sockets plus a standard header with 22 GPIOs. In addition to the versatile programming and development options, full details of the BOM and reference PCB layout are available and can be used to simplify the design effort for your product.


Figure 2: C027 Starter Kit


Figure 3: m-center

The EVK-G31 and G35 evaluation kits are more traditional boards but still come fitted with a u-blox GPS receiver module. The SARA module plugs into the main board so that the kit can be used with different cellular modules simply by swapping the plug-in units. To support the evaluation board, u-blox supply their excellent m-centre (cellular) and u-centre (GNSS) interactive software tools that facilitate configuration, testing, visualising and data analysis of the cellular and GPS receivers.


The SARA series of cellular modules from u-blox provide a full range of cellular connectivity technology with global reach.  The use of a common and very compact form factor provides a simple drop-in upgrade path so you can add new services and features to your product without costly layout changes.