For industrial IoT applications, cost-effective and energy-saving connectivity is a prerequisite for economically viable implementation. The growth of IoT deployments and the realization of future IoT innovations will be determined by the range of LPWA network technologies. However, LPWA use in practice is currently still very limited. Although there are practicable solutions, these are concentrated in specific coverage areas, mostly in metropolitan areas. In addition to network coverage, there are differences in terms of transmission rate and power consumption, but also in terms of security, scalability and interoperability. Companies' IoT strategies are currently being held back by sometimes significant limitations in terms of coverage and mobility. Network management can also be complex and costs difficult to control.

Existing LPWA technologies

The unlicensed technologies from Sigfox, Ingenu, LoRa and similar alternatives require a large-scale network rollout at national and international level. This will take time - so restrictions must be taken into account for the time being. Licensed LPWA variants such as the two currently competing standards NB-IoT (Narrowband-IoT) and Cat-M1 use the LTE mobile network, but cross-border interoperability has not yet been clarified.

Sigfox: The market for the Sigfox network is limited to certain geographical areas in around 50 countries in which Sigfox operates. At just one euro per month or even per year for each IoT device - depending on the volume of devices - the costs are low. Each device can transmit a 12-byte uplink message up to 140 times per day. This compares to a limited bidirectional communication of four 8-byte messages per day. Roaming is restricted to the coverage areas and availability in rural regions is limited.

Lora: LoRa technology was developed to enable long-distance communication at a low bit rate between 'things' such as battery-powered sensors. The technology is suitable for local coverage in urban areas, for communication at fixed locations. LoRa is used worldwide, but is limited to the countries in which the members of the LoRa Alliance are active. In addition, LoRa is not a stand-alone end-to-end connectivity solution and requires capital investment.

In most deployments, LoRa needs to be connected to a cellular network to actually connect to the Internet to load its data. The frequency is limited to a single provider, which means that the spectrum is not exclusively reserved for a single network. Thus, there is no control over capacity availability. This would be like if the Wi-Fi at home could be used by all the neighbors.

LTE: NB-IoT or LTE-Cat1M: There are already many chipset and hardware providers that are divided into the two camps of NB-IoT or LTE-Cat1M, which creates more complexity in the manufacturer market. Roaming between Cat-M1 and NB-IoT networks is not possible. NB-IoT and Cat1-M are currently only in the test phase in most countries. Some US carriers - Vodafone Spain and Telstra - have already started commercial operation. The global rollout and interoperable roaming coverage across carriers, which still needs to be negotiated, will take many years. Until then, it is not possible to develop solutions that are easy to implement worldwide. As roaming is currently not available, offers are limited to domestic markets. One advantage of both options would be the low power requirement. However, no independent end-to-end connectivity solution is yet available for these two licensed standards either.

Alternative with worldwide coverage

Thingstream positions itself as the connectivity layer between the devices and the IoT platforms.

© Thingstream

When selecting an IoT connectivity solution, it is important to take this into account: How much effort is required to convert the data from the 'things' into a meaningful format so that it can be captured by an IoT platform? And: How can it be ensured that messages from the 'things' reliably reach the IoT platform?

The 'Message Queue Telemetry Transport for Sensor Networks' (MQTT-SN) protocol, which is often used for IoT network traffic, is suitable for this. This is a lean publish/subscribe messaging protocol for M2M telemetry that has been specially developed for low-bandwidth environments. MQTT-SN has integrated quality of service (QoS), which is important for IoT applications. For example, QoS 2 can be used in a critical application such as monitoring HVAC applications (heating, ventilation, air conditioning). The service ensures that the sensor guarantees the transmission of an alarm message by having the protocol handle the retransmission. QoS - 1 is unique to MQTT-SN and primarily used for regular alerts from non-critical systems such as a cargo tracker that can ping every hour. If some messages do not get through, this does not matter. MQTT-SN allows a user to choose the QoS level depending on their network security and application logic.

The combination of communicating MQTT-SN and a global, almost ubiquitous GSM network (available in over 190 countries) is a forward-looking concept for common IoT requirements. Thingstream has entered the LPWA market with this concept. The company offers cost-effective IoT connectivity with international coverage and mobility support - as an end-to-end connectivity solution. The technology is based on GSM connectivity without relying on SMS or a cellular data connection. This approach enables devices to connect to virtually any GSM network worldwide. Using MQTT messaging, small amounts of data can be sent quickly and reliably at low cost - starting at USD 1 for low volumes.

Thingstream also supports unrestricted bidirectional communication. The technology has been developed for use in many vertical sectors, including asset tracking, logistics, supply chain, facility management, energy and environmental monitoring.

Potential to become the future standard

The SIM-based model also promises network operators new revenues in their mobile networks. Thingstream avoids the problem that licensed LPWA technologies such as LoRa and Sigfox have: the need to provide a dedicated network that covers a specific geographical area. In the case of LoRa, users also need technical staff to operate the network. Licensed LTE-based LPWA offerings such as NB-IoT or LTE-Cat1M also already exist, but only on a national level, as roaming issues are still unresolved.

Even though IoT strategies are being propagated in many places and initial projects are being driven forward, everything stands and falls with connectivity. Among the LPWA technologies that have emerged in recent years, there has been no end-to-end connectivity solution that can be used across borders and is still cost-effective. Thingstream provides an alternative here.

Author:
Neil Hamilton is Vice President of Business Development at Thingstream.