When we speak of SIM-less Mobile communications in mobile telephony, we talk about a technology oriented to remove the current SIM cards. The Industrial SIM-less concept is applied to Industry, Infrastructure and Smart Cities. We can describe as Industrial SIM-less communications those not depending on GSM/GPRS/3G/4G traditional operator solutions.
In the industry, infrastructure and Smart Cities environment, the amount of points to be communicated is very high. Due to the high number of points to communicate, the cost of hardware and the power consumption of 3G/4G technologies, it’s necessary to find another, or some other technologies to solve this scenario.
Regarding SIM-less Mobile communications, we can say that ETSI and GSMA are working on the standardization of SIM-less technology for mobile telephones. The implementation involves a specific eSIM hardware that replaces the current SIM.
There are several advantages beforehand. eSIM can be reprogrammed, so it would allow an easy network migration. The traditional issues associated to SIM cards, such as mechanical/electrical connection failures, are also removed with eSIM. SIM-less Mobile applies a set of technologies that provide a communication solution for a high number of sensors, with low-cost and low energy consumption. There are two different approaches or solutions for two different scenarios:
A first scenario represents a set of sensors which require data communication usually by exception, programmed and for a specific time, or depending on the event – digital signal, temperature above or under a threshold. In this first scenario, data flow in one direction, from the sensor to the data acquisition system. Only occasionally it’s possible to communicate from the acquisition system to the sensors. In a scenario with a high or very high sensor density, the advisable solution is based on a Global Data Communication network. GSM/3G/4G communication technologies cannot be used in ultra-low consumption devices. By the other hand, the frequencies used in GSM/3G/4G are not suitable for low-power systems.
The Global Data Communications network must use radio-based technologies that enable the communication between sensors placed in hard-to-reach locations, sometimes underground, and at the same time able to work with very low power, since they are low-power devices.
Operator solutions, like the SIGFOX network, offer an international coverage and operate ISM radio bands with UNB technology. Thanks to these features, these networks are able to solve the first scenario.
A second scenario includes a set of sensors and actuators that require data communication with the data acquisition system, which by their side require commands to be sent to actuators. In this scenario the communications flow in both directions – unlike the previous scenario, where communications went from sensors to monitoring or very rarely from monitoring to sensors. In a scenario with a high density of sensors and actuators, which require bidirectional communications, the suitable solution is a short-range Wireless Network. In this scenario, traditional GSM/3G/4G technologies are not valid for the same reasons as in the previous scenario.
A Short-Range Wireless Network must use radio-based technologies for a bidirectional communication between the data acquisition system, and the sensors and actuators placed in hard-to-reach locations. At the same time, a low power should be feasible being low-power devices. The frequencies used must be low enough to enable a good penetration inside manholes, cabinets, buildings, etc.
ISM radio modems, along with ISM wireless sensors and actuators, combined with gateways or Universal Gateways, shape the solution for the second scenario.It should be emphasized the emergence of technologies halfway between operator solutions, like SIGFOX, and short-range wireless private network solutions. Radio-based technologies like LoRa enable the implementation of short- and medium-range wireless communication networks.
The SIM-less concept for industrial communications does not stand for the use of SIM in mobile telephones, but to data communications with sensors and actuators, in low-power environments with a high density of devices. We can use the term Industrial SIM-less for all low-power wireless data communications apart from GSM, 3G, 4G, WiFi, WiMAX, conventional analog radio and conventional digital radio communications.