Process communication failure! This notification could soon appear on screens in many supervisory control rooms when providers shut down 3G technology and communication with remote stations connected via cellular communication. But when will this scenario become a reality? And what measures should system operators take before then to ensure continuous data?
The Internet of Things (IoT), Industry 4.0, and 5G: Numerous new technologies are currently under discussion. Despite all the advantages they might bring in the future, one problem that will then present itself to system providers is almost entirely ignored: In Germany, 3G cellular communication technology will be shut down first. But why 3G when 2G, an even older wireless technology, is still in use? The capital letter G stands for “generation”, and is used as a generic term to refer to all the stages of technological development cellular communication has gone through. The analog first-generation predecessors, also known as class A, B, and C networks, were characterized by expensive end devices the size of the trunk of a car, incompatible networks, and their lack of suitability for use by the masses. The second generation represented the first cellular network in the current sense. 2G was uniformly specified by a working group called Groupe Spécial Mobile (GSM). It is comprised of the D1 network of Deutsche Telekom (formerly known as Deutsche Bundespost), the D2 network of Vodafone (called Mannesmann, back in the day), and the later E1 and E2 network of Telefónica (formerly known as E-Plus and o2). In terms of technologies, 2G includes GSM (Global System for Mobile Communication), GPRS (General Packet Radio Service), and EDGE (Enhanced Data Rates for GSM Evolution).
With Internet use increasing, data communication has continuously become more important, resulting in telephony and SMS text messaging no longer being the driving forces behind the advancements. To address the new challenges, the 3GPP (Third Generation Partnership Project), a new organization, was created to develop the 3G standard with the UMTS (Universal Mobile Telecommunications System), HSPA (High Speed Packet Access), and HSPA+ technologies. Finally, LTE (Long Term Evolution), more widely known as 4G, with its even higher data rate, heralded the last giant leap in this technological development. Strictly speaking, it needed to be called 3.9G in the beginning, because not all of the specifications were met until LTE Advanced and LTE Advanced Pro appeared. Additionally, the fourth generation includes current technologies such as LTE-Cat-NB1 (NB-IoT) and LTE-Cat-M1 for the Internet of Things, the first to focus on low-data communication in cellular networks.
Poorer network coverage
In order to understand why the 3G network will be the first to be shut down, we need to look at two significant aspects. The first is network coverage. In Germany, the 2G network provides the best coverage, and therefore serves as the backbone of cellular communication without the need for additional investment. Used as a fallback, 2G provides the best solution for telephony (emergency calls and SMS) and already-existing M2M applications. The second aspect is the data rate. The 4G network provides the consumer market with the required bandwidth, while 3G, with HSPA+, only delivers 42 Mbps. In 2014, the German government set a goal to provide every household with a 50 Mbps Internet connection. Because 3G couldn’t comply with these requirements after the Federal Network Agency’s spectrum auction in 2015, the providers decided not to expand the network.
But even before 2014, 3G network expansion had been lagging. This was due to the licensing costs that arose during the spectrum auction of the UMTS frequency bands. The 100 billion German marks paid back then were lacking for the later network expansion. This explains why money is only being invested in the 4G network, with LTE coverage already outperforming the 3G network today. Ultimately, the 3G network has lost its importance, and its frequency bands can be used more effectively by network operators in the 4G network.
With this in mind, the term “shutdown” doesn’t actually quite fit. Taking into consideration that space is being freed up in frequency ranges, “re-farming” is a more fitting term. Even after the official shutdown date announced by the network operators, no switch will be flipped to stop everything from working. At that point in time, however, customers will no longer be able to use the 3G network. The providers will gradually retrofit the network cells for the newer technologies. So, even shortly after the official shutdown date, system operators may well have the bad luck of seeing their 3G devices fail to connect to the network. More detailed information about the dates must be requested directly from the specific network operators, as dates vary among the providers.
Deutsche Telekom (the D1 network) already addresses network availability in its General Terms and Conditions. Their cellular communication service description states that the listed 3G network technology [...] in Telekom’s cellular network will only be available until December 31, 2020, subject to extension. There is no comparable written statement yet regarding Vodafone’s 2D network. Chief Technology Officer Johan Wibergh announced only that the company was planning for a 3G shutdown in 2020 and 2021. Telefónica’s network technology will have the longest support. In this provider’s 2019 strategy update, the 3G shutdown is scheduled to take place no earlier than at the end of 2022.
The 4G switchover has its advantages
How should system operators proceed to prevent communication to their remote stations from being interrupted? First, it must be checked whether 3G devices are being used for data transmission and whether the current data rate is really necessary. In fact, for simple machines requiring a small communication volume, even a 2G connection may be sufficient. If the cellular device provides an option to prevent connection to the 3G network, a simple field test can be performed to check whether the system remains available via the 2G network.
Even if the application can communicate with the control room via 2G, it is worth considering the newer technologies because modern IoT networks, such as LTE-Cat-NB1, can justify the investment in new hardware in some circumstances due to lower connection charges. It may even be possible to replace a combination of a sensor, a controller, a power supply unit, and a router for a simple pump application with one single battery-powered IoT device. In contrast, a classic 4G router offers additional options, such as the transmission of images from a surveillance camera. Besides the hardware, the cellular service contract should never be overlooked. It is to be expected that German third-party providers such as congstar and Aldi Talk will expand their service contracts through access to the LTE network; however, users will need to inquire about it in advance.
5G availability in the future
Even if most of the talk today is about 5G, this standard doesn’t yet concern today’s system operators. 5G starts with a focus on high data rates (release 15). To achieve them, the network cells become smaller and the enhanced coverage will be limited initially to urban locations. The requirements for mMTC (Massive Machine Type Communications) or uRLLC (Ultra Reliable Low Latency Communications), which haven’t been defined yet, will be implemented no earlier than in 2020, during the next evolutionary stage (release 16), or are already covered by the existing IoT networks. At the moment, it is neither possible to say when serial devices that are suitable for industrial applications will be available at reasonable costs, nor when rural 5G coverage will be complete. Therefore, current legacy applications that do not need to use the new 5G functions don’t need to address the topic of 5G in the context of the 3G network shutdown.
With all this said, users don’t need to anticipate sudden interruptions of process communication. After the official dates that start at the end of 2020, the providers won’t shut off all 3G network cells throughout Germany, but they will remove them step by step. It is therefore not possible to say exactly when which station needs to be retrofitted for the newer technologies. Nevertheless, every system operator should draft an appropriate schedule, taking into account the specific priorities of data, and considering whether an IoT approach or a classic LTE connection would best fit their application.
Comprehensive 4G portfolio
Phoenix Contact’s 4G cellular product portfolio offers the right solution for every demand: From simple alert and switching tasks and classic remote control applications through to global remote maintenance services for machines and systems. Since fault notifications should be the exception, it is recommended to use an event-oriented communication approach implemented using the TC Mobile I/O product family. These devices inform the control room or employee in the field by SMS, e-mail, or app. SMS technology remains a cost-effective alternative for small data volumes, and therefore will remain a fixed part of the LTE network.
For continuous, economical data exchange with remote stations via VPN and remote control protocol, the devices from the TC Router series are the most well-suited. Last but not least, the focus of the TC Cloud Client and TC mGuard product families is on the remote maintenance of machine building facilities, which are constantly becoming more and more automated. In addition to more servicing by the machine building company’s experts, these applications require routine software updates due to increasing security requirements (IEC 62443 or ISO/IEC 27001). For these purposes, the IT networks of the machine building and operating company must be securely connected, and the numerous global VPN connections must be managed.
Dennis Lüttge, Communication Interfaces Product Manager, Phoenix Contact Electronics GmbH, Bad Pyrmont, Germany