0 2 0 0 4 0 0 6 0 0 8 0 0 1 0 0 0
0
5
1 0
1 5
2 0
2 5
3 0
N u m b e r o f d e t e c t e d o b j e c t s
T e s t d r i v e t i m e [ s ]
r e s i d e n t i a l
r e s i d e n t i a l
r e s i d e n t i a l
u r b a n a r t e r i a l
u r b a n a r t e r i a l
Figure 8: Number of suitable objects detected by the
test vehicle during the test drive on urban arterial roads
(Bergstraße, Zellescher Weg, Teplitzer Straße in Dresden,
Germany) and residential areas. Total test duration is 1150s,
measures were taken for every 0.1s interval.
tion partners, which might themselves detect a similar
amount of objects. This gives rise to the idea to adapt
the CPM generation rules to the current driving en-
vironment, e.g., sending information with 10 Hz on
residential roads and using mitigation techniques on
the larger urban arterial roads as well as on highways.
While this proposal is backed by the initial data, much
more test drives would be required to determine its
actual feasibility. One could also consider if it is use-
ful to use the perceivedObjectContainer to its full ex-
tent allowed by the specification. In particular, giving
only two classification results instead of the allowed
eight would reduce storage requirements in the 29 ob-
jects case by 326 Byte alone, although this is still not
enough to avoid message segmentation. On the other
hand, when only considering information currently
available, all 29 objects can be transmitted in a sin-
gle CPM. On a more general note, inclusion of spe-
cific optional information in the CPM could be made
dependent on the amount of objects sensed by the ve-
hicle. For instance, even when giving complete infor-
mation, about 20 objects (depending on the size of the
other containers) can be included in the CPM without
the need for segmentation. This number increases to
40 objects when considering the information available
at the experimental vehicle. Finally, when sending
only the required data fields, up to 75 objects can be
included.
5 CONCLUSIONS
In this paper, test drives with a real experimental ve-
hicle were conducted to assess the number of objects,
which can be detected by a modern car. Sensors were
chosen such that the equipment of future vehicles (at
least in the near future) could be mimicked. The re-
sults show that even under today’s conditions a seg-
mentation of the CPM might be required.
Future work includes measurements under differ-
ent traffic conditions, e.g., different day times and
street conditions, and on different streets as well as
measurements on highways. Large scale data acqui-
sition, taking into account other probe vehicles with
different sensor setups, is necessary to determine if
the proposed scheme of making the generation rules
dependent on the driving environment is actually fea-
sible. In addition, the derived results can be fed back
into communications network simulations to assess
the necessity of employing CPM mitigation strategies
under the current conditions. This is especially of in-
terest as current research (ETSI TR 103 562 V2.1.1
(2019-12), 2019; Yu, 2020) has shown that the miti-
gation strategies, while reducing channel load, might
also decrease service availability. Finally, the object
fusion algorithm as well as the object choosing al-
gorithm provided by ETSI, which were omitted here,
can be implemented, allowing to generate and directly
evaluate the resulting CPM message size under vari-
ous conditions.
ACKNOWLEDGEMENTS
This research is financially supported by the Ger-
man Federal Ministry of Transport and Digital
Infrastructure (BMVI) under grant numbers FKZ
01MM19003D (ErVast) and co-financed by the Con-
necting Europe, Facility of the European Union (C-
ROADS Urban Nodes). We would like to thank Ina
Partzsch for her valuable suggestions and comments.
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