Reliable mobile phone reception and super-fast Internet via 5G mobile communications should remain a dream for many rail travelers for the time being. There are currently no plans to equip Deutsche Bahn (DB) long-distance trains with special signal amplifiers for 5G. “As part of the cooperation with the mobile network operators, it was agreed that no 5G upgrade of the repeaters would be promoted at the moment,” explains the federal government in a heise online response to a request from the CDU/CSU parliamentary group. For the time being, the new generation of mobile communications will be left out on many trains.
In the case of mobile phone coverage within a rail vehicle, further precautions such as the installation of repeaters or the use of high-frequency permeable panes are required. For legal reasons, however, the mobile network operators cannot install and maintain components in and on the train themselves and therefore have no direct influence on the implementation of such measures. The providers must be able to supply the rail routes, on which more than 2,000 passengers are transported every day, within the framework of the requirements from the 2019 frequency auction. However, the condition does not refer to ensuring coverage on the train itself.
Bahn checks disc change
For 5G in DB long-distance traffic, everyone involved now swears above all by “mobile phone transparent panes”, as the lead Federal Ministry for Digital Affairs and Transport (BMDV) writes. Such a “technology change” will be examined at the railways. This also applies to updating the WLAN system to 5G. To the knowledge of the government, DB competitor Flixtrain is not planning to upgrade the cars it operates or on its behalf to 5G either. However, this company uses uncoated panes, which do not require a “conversion or upgrade” for frequency transmission.
The situation is different for DB trains. According to the government, these are “provided with an insulating metal layer to enable energy-efficient air conditioning of the vehicles”. In addition to thermal radiation, the additive also shields mobile phone signals and thus causes “a high level of mobile phone attenuation”. With the existing trains in DB long-distance traffic, this is overcome with the help of repeaters. Newly ordered and incoming fleets such as the ICE 3neo (73 trains by 2029) or ICE L (23 trains in stages from 2024) are equipped with mobile phone transparent panes ex works. Such window fillings are currently being retrofitted to the Intercity 2K.
At the same time, almost all traction vehicles and locomotives that operate in the DB network are to be equipped with GSM-R radio systems. With these there is no risk of interference from mobile devices in the high-performance LTE 900 network, in which up to 35 Mbit/s capacity per cell is available even in closed rooms. Originally, this additional 4G radio frequency was to be put into operation in trains with the timetable change in December. In November, however, the Federal Network Agency suspended the obligation to harden the train radio system by switching to GSM-R.
The aim of the federal government is “that the conversion of vehicles not yet equipped with interference-resistant GSM devices be completed as quickly as possible”. The BMDF is “in exchange with the railway industry and the railway companies”. The sticking point is a further conversion requirement of around 1000 vehicles, in particular due to limited resources in the sector, while around 10,000 have already been converted under the GSM-R funding guideline. The federal government therefore sees restrictions on the use of the frequency range around 900 MHz for mobile communications “until the end of 2024”.
With 5G in the dead zone
The CDU member of the Bundestag Thomas Jarzombek rated the 5G train announcement to the “Rheinische Post” as “hammer” and “bad news for all train passengers”. This not only keeps the network significantly slower. Areas that are covered with the new frequencies between 3.7 and 3.8 GHz with modern 5G are even “dead spots” for the old train repeaters.
Possible upgrade for older trains: A diamond pattern is cut into the coating of the window glass with a laser so that cell phone waves can penetrate.
A DB spokesman replied evasively to a question from heise online about the performance data of the signal amplifiers currently in use: Together with Deutsche Telekom and Vodafone, the group is working “on a seamless cell phone network along the rails”. By 2026, the tracks would be continuously supplied by the two network operators with 200 Mbit/s or more. These available data rates could all be piped onto the trains. The spokesman did not comment on the largest local mobile communications provider, Telefónica Deutschland with the o2 brand.
First, repeaters for 2G, later for 3G and since 2016 for 4G mobile communications were installed in the ICE trains, according to DB. The current repeater generation was specified by the mobile network operators and then used in the ICE trains by the long-distance transport division. As a permanent solution one sees cellphone-permeable panes in which the metal layer is “broken by a barely visible grid”. In addition to the correspondingly equipped new trains, windows on an older ICE have now also been successfully “reworked using a laser”.
(vbr)
