In order to make the mobile internet and a high voice quality coexist well on smart phones, all three German operators rely on VoLTE. The acronym stands for Voice over LTE, which means conducting phone calls via LTE-based data packets.

The drivetests and walktests conducted by P3 show that this is working effectively by now. The Samsung Galaxy S7 phones that were installed in the test cars as well as in the backpacks of the walktest teams permanently established voice calls to their defined counterparts. The calls that originated in the test cars were set up to the according smartphones in another car. The phones in the walktest backpacks called stationary ­receivers. In order to simulate common smart phone utilisation, the mobile phones transmitted parallel data streams in the background of the telephony tests.

Close voice race between Vodafone and Telekom

The test drives in larger cities conveyed the same picture that also could be observed in the subsequent disciplines: The race between Telekom and Vodafone was neck to neck, O2 followed at considerable distance. Still, the Telefónica network achieved far better results in the big city walktests compared to the results of the drivetests. This indicates that O2 offers better coverage in inner-city locations where there is a lot of foot traffic.

Compared to last year‘s results, Vodafone managed to considerably improve the call set-up times in its network. In this regard, the Dusseldorf-based provider beats its competitors in all tested scenarios with the only exception of voice calls in railways. Deutsche Telekom holds up with slightly higher success rates – again, with the exception of rail journeys.

In smaller towns and on the connecting roads, both contenders offer high quality as well. Telefónica‘s network, that still suffers from the ongoing integration of O2‘s and E-Plus‘ formerly separate radio cells, falls back considerably outside of the big cities. In those locations, we see a distinct drop in the level of the measured values.

When it comes to conducting phone calls in trains, the performances of neither operator are a glorious chapter – especially when bearing in mind that the results in this discipline looked far better last year. Despite Vodafone being a small step ahead, there is much room for improvement in all considered networks.

We are awarding 60 per cent of the achievable points in the data discipline. This pays tribute to the fact that internet communications and streaming applications nowadays have the biggest share in smartphone usage. The demanding measurements conducted by the drivetest and walktest teams are also reflecting these conditions: The smartphones regularly access the most popular web sites according to the renowned Alexa ranking. Furthermore, they invoke the static ETSI reference web page, also known as “Kepler page“. We evaluate the speed and reliability of data transfers with downloads of 3 MB and uploads of 1 MB test files. Furthermore, we gauge the amount of data travelling over the network in a seven-second period.

Clear ranking order in the data discipline

The data tests in the big cities confirm the results of the data discipline – almost regardless of the number of the cities’ inhabitants. In comparison to the previous year‘s results, the leading duo Telekom and Vodafone succeed in taking their performances up a notch especially in urban areas. We are particularly impressed by the high success ratios of the leading duo. In big cities and smaller towns alike, this year‘s network test confirms the high availability and stability of LTE mobile network coverage.

However, Telekom takes a clear step ahead of Vodafone in the data discipline and builds the foundation of this year‘s overall win on this. The lead is most distinct regarding the upload and download data rates. Above that, the really fast transmission speeds in both networks are a good indication of the advanced stage of completion of the so-called “carrier aggregation“ – increasing data rates by means of combining several LTE frequency bands.

Performance losses at O2

But our test results also expose the problems currently met by Telefónica and its customers. Since O2 acquired its former competitor E-Plus in October, 2014, the technicians have been working hard in order to consolidate the formerly separate cells of both networks. The measurement values at hand clearly indicate that this task is everything but trivial. The O2 network already ranked distinctly behind Telekom and Vodafone in our previous mobile network test (2016/2017). But this year, the gap did actually increase.

O2 manages to keep up its last year‘s level in the drivetests conducted in larger cities. However, the operator massively loses points in the inner city walktests. This suggests that fine tuning the merged networks is especially demanding at locations with high numbers of users simultaneously accessing the mobile network. Considerably lower success ratios and data rates than those delivered by Telekom and Vodafone result in a significant loss of points for Telefónica. Customers who join O2 due to its undoubtedly attractive tariffs must, at his point in time, be somewhat patient especially when they are using the mobile internet.

Vodafone makes up leeway over Telekom in smaller towns

In the drivetest conducted in smaller towns, O2 also ranks substantially lower than in the previous year. At least, the level of results rises a little in this scenario in comparison to the inner city walktests. As was to be expected, the leading duo also shows somewhat weaker results in the smaller towns than in the metropolises. Interestingly, in this category, Vodafone catches up closely to Telekom. Especially the success ratios of the Dusseldorf-based contender are a tiny step ahead of its Bonn-based competitor. Telekom counters this with slightly better data rates as well as an excellent Youtube performance.

Distinct ranking order on connecting roads

After observing the voice performance as well as the data tests in cities and towns, the ranking determined on the connecting roads comes hardly as a surprise: Telekom and Vodafone fight closely and at eye level. O2 follows at a distance, but achieves better results than in the voice discipline.

All in all, Telekom gains the win in this category – but Vodafone hold up very well too. When customers of O2 are travelling on the roads, they should expect lower success ratios when surfing the web, transmitting data or accessing audio/video streams as well as slower data rates. 

Our test results clearly emphasize: For a high level of connectivity on German autobahns and country roads, there is currently hardly a viable alternative to the offerings of Telekom and Vodafone.

“When it comes to connectivity in German railways, there remains a lot of work to be done.“ This was the conclusion of the corresponding section of our mobile network test one year ago. So, this year, our test teams started their tasks with eager expectations and successfully completed more than 30 hours of travelling in various ICE and IC trains. Especially in the ICE flagship trains, Deutsche Bahn has recently made extensive upgrades to their cellular and online coverage.

In the face of these efforts, the results are somewhat disappointing – particularly as all three German mobile operators were further ruffled in comparison to the mobile connectivity results obtained in the previous year. However, for the sake of fairness, we have to mention that the test connections did not make use of the WiFi hotspots that are meanwhile available in almost all ICE trains, but exclusively used the mobile networks. Still, they too should be receivable in good quality due to elaborate repeater technology in the railway waggons. Unfortunately, the result is still indisputable: When looking across the borders to Austria and especially to Switzerland, German railway customers can be only jealous. Both alpine countries are ahead in this discipline at an enormous distance. 

Still need for improvement on German railways

It is not a very high level on which Vodafone beats the overall winner Telekom in this discipline. Success ratios and data rates of web-page downloads and Youtube playbacks as well as file transfers leave a lot to be desired in all three considered networks. The weakest candidate in this category, O2, failed at a quarter of all attempts to use an online connection in trains. When accessing Youtube, this number even rose to about half of the attempts. So this year‘s conclusion sadly is: When it comes to using the internet in German railways, there still remains a lot of work to be done.

Deutsche Telekom managed to grow once more on its results of the previous year. And although its Dusseldorf-based competitor also improved, the Bonn-based operator celebrates its seventh win in a row on the occasion of our network test 2017/2018. Telekom gains the overall win particularly in the data discipline. But also for Telekom, there still remains work to be done. This especially applies to voice and data connections in German railways.

In the voice discipline, Vodafone catches up with Telekom up to a distance of just one point. The final showdown and overall win of the Bonn-based competitor was decided in the data category – even if the Dusseldorfers also deliver a respectable performance in this discipline. So Vodafone fully deserves the overall grade “very good“. In the railways, Vodafone is even a small step ahead of Telekom – but there is still room for improvement in this category as well.

Compared to last year‘s results, O2 falls behind severely. The supposed reason for this are the challenges of the still ongoing network merger with E-Plus. So, in our network test 2017/ 2018, Telefónica again only achieves the overall grade “sufficient“. We send our best wishes to the Munich-based operator and its customers, hoping that this difficult phase may soon be over and that next year‘s test results will reflect true advancements.>>