If you want to change connectivity, when your connected objects already communicate in LoRa or Sigfox, you have to have several elements in mind, including replacing the antenna.
Should we keep our connected objects in LoRa or Sigfox, or should we change their connectivity, given the context of uncertainty that has prevailed in recent months with the end of Objenious’ LoRaWAN network and Sigfox’s receivership? “This is a real strategic question for a manufacturer of connected devices”, says Hatem Oueslati, CEO and co-founder of IoTerop, a French software publisher expert in the LwM2M protocol, which advises customers to move towards the cellular, more durable in his eyes. But to migrate to another connectivity, you have to think about five main elements.
“We cannot make GSM with components initially developed in LoRa”
First to change the antenna. Whether it is to switch to cellular, for example to NB-IoT, to satellite, or to Wize technology, a new module must be integrated. “Designs made for LoRa and Sigfox are not compatible with others,” recalls Thibault Stabat, business development manager at French IoT operator Iowizmi and development manager for the Wize Alliance. Thus, Ubiwan, a French fleet management software publisher that has been offering LoRa products since 2015, had to prepare a new range to integrate LTE-M into its GPS trackers. “We cannot make GSM with components initially developed in LoRa. Changing connectivity requires new products”, testifies David Babin, CEO, who considers multiconnectivity as a long-term guarantee.
But beware, a communication protocol is not equivalent to a single antenna. “There are LTE-M / NB-IoT modems, others in NB-IoT / 2G. The choice has an impact on the time to market”, warns Hatem Oueslati, advising customers to carefully study the offers of the different module builders. To facilitate the choice of customers, the operator and supplier of satellite IoT Kinéis is in reflection with other players to have a synergy between satellite modules and LoRaWAN. Similarly, SFR will discuss with engineering schools to find a solution to make a LoRa object that does not have a SIM card easily insert a SIM card reader.
The layout on the electronic board
The layout of the components on the electronic board follows from this, the second key point to keep in mind. “We will have to think about how to place the module on the electronic board to avoid interference. This may require redesigning the PCB because all the antennas do not have the same ground plane”, warns Guillaume Triquet, project engineer at Kinéis. To simplify customer procedures, Kinéis has “tested different antennas on its frequency bands to promote integration at lower cost without changing the entire design of the object”.
“Each communication protocol has its transmission strategy”
Battery requirements are also to be taken into account. “Each communication protocol has its transmission strategy with different powers, so you have to reassess whether the battery used is suitable with the new communication protocol chosen”, indicates Guillaume Triquet. Hatem Oueslati, at IoTerop, is delighted that the water meter manufacturer Edmi is displaying NB-IoT products that could reach a lifespan of 20 years.
In the software modifications to be made, security is one of the central elements. “On the LoRaWAN, there is a security layer integrated in the data transport which generally allows to encrypt the data sent from the device to the LoRa Network server. In the NB-IoT, this security layer must be planned / implemented directly by the manufacturer of the device since it is generally not directly included in the NB-IoT transport”, warns Hatem Oueslati. Customers must therefore choose a security protocol and implement it themselves on top of the NB-IoT to ensure, in particular, data encryption and end-to-end device authentication, from the device to the cloud. “We must choose appropriate protocols that allow the constraints of NB-IoT transport to be overcome, such as DTLS and Oscore”, adds Hatem Oueslati before specifying: “The advantage is that LTE-M and NB-IoT are directly wired over IP, an interoperable network layer, which allows objects to be operated directly on the cloud platform without going through a third-party infrastructure, whereas with LoRa, you had to go through gateways.”
In parallel with its hardware and software modifications, customers must clearly define the use and position of their connected objects. If the object is located underground, it will therefore be wiser to swap its LoRa or Sigfox technology for NB-IoT rather than for satellite. “Satellite is four to five times more expensive than Sigfox technology, so you have to carefully assess the use for it to be relevant”, warns Guillaume Triquet, at Kinéis, who observes a strong demand for asset tracking and Agriculture. The rise of 5G and the launch of the Kinéis constellation in 2023, with 25 operational nanosatellites, is an additional reason to wonder about a connectivity migration.