# On the Needs and Requirements Arising from Connected and Automated Driving
## 4 Technical Requirements: from Automotive to Network Perspective
### 5 GCAR Use Case Technical Requirements
#### 4.3.2 Cooperative Perception Based on See-Through  
An overtaking scenario is considered as a motivation for the see-through use case, where we consider, as illustrated in Figure 2, two vehicles [PERSON]\({}_{1}\) and [PERSON]\({}_{3}\) driving in the same lane, with a speed of 50 km/h and a legal headway of two seconds. A third vehicle ([PERSON]\({}_{2}\)) is moving in the opposite direction, with a speed of 100 km/h. [PERSON]\({}_{1}\) wants to overtake [PERSON]\({}_{3}\) and it requests a real-time video from [PERSON]\({}_{3}\). [PERSON]\({}_{1}\) needs to change its lane, increase its speed with an acceleration limited to 2 m/s\({}^{2}\), to complete the overtaking maneuver. With a lateral speed of 2 m/s, approximately two seconds are needed to change the lane of four meters width. In this configuration, it takes 6 s and 120 m to have [PERSON]\({}_{1}\) and [PERSON]\({}_{3}\) at the same level, and an additional two seconds to regain the correct headway at the end of the overtaking. During the total eight seconds, [PERSON]\({}_{2}\) has traveled 220 m. An additional 160 more meters are considered to provide safety buffer for avoiding the collision, resulting in a total overtaking distance of around 400 m.  
Based on this scenario, the following automotive requirements have been identified: completion time, minimum inter-vehicle distance, relevance area, and mobility. The completion time is equal to \begin{table}
\begin{tabular}{c c c c c c} \hline
**RequirementUse Case** & **Lane Merge** & **See Through** & \begin{tabular}{c} **Network Assisted** \\ **Vulnerable** \\ **Pedestrian Protection** \\ \end{tabular} & \begin{tabular}{c} **High Definition** \\ **Local Map** \\ **Acquisition** \\ \end{tabular} & \begin{tabular}{c} **Remote Driving** \\ **for Automated** \\ **Parking** \\ \end{tabular} \\ \hline Communication Range & \textgreater{}350 m & \textless{}100 m & \textgreater{}70m & \textgreater{}1 km & several kms \\ \hline Latency & \textless{}30 ms & 50 ms & \textless{}60 ms & \textless{}30 ms & 5 to 30 ms \\ \hline Reliability & 99.9\% (high) & 99\% (medium) & 99\% to 99.99\% & 99.9\% (high) & 99.999\% \\ \hline \multirow{3}{*}{SDU Size} & \
\begin{tabular}{c} 12,00-16,000 \\ bytes per message \\ \end{tabular} & 41,700 bytes per frame & 1600 bytes per message & Up to 60 bytes & UL: 41,700 bytes & DL: 16,000 bytes \\ \hline \multirow{2}{*}{Data Rate} & \multirow{2}{*}{1.28 Mbps} & from 14 to 29 Mbps & \multirow{2}{*}{128 kbps} & DL: 960 kbps + & from 6.4 to \\  & & & Mbps & 1920 kbps & 29 Mbps \\ \hline \multirow{2}{*}{Availability} &
\begin{tabular}{c} 99\% \\ (medium) \\ \end{tabular} & 99\% (medium) & 99.9\% (high) & 99\% (medium) & 99.999\% (ultra-high) \\ \hline \end{tabular}
\end{table} 
Table 2: Network requirements for the 5 GCAR use cases. 10 s. As the vehicle transmitting the video and the vehicle receiving are driving in the same direction, a relative mobility between 0 to 30 km/h is considered. Although the relevance area is highly dependent on the speed, based on the calculation above, between 300 and 500 m is judged as being needed for a safe overtaking maneuver. From a network perspective, the required communication range can be derived from the minimum inter-vehicle distances. The communication range of 50 to 100 m is sufficient at 28 m of headway, as the two vehicles Veh\({}_{1}\), Veh\({}_{3}\) involved in the video exchange are driving in the same lane. The amount of data to be transmitted is proportional to the camera resolution and the processing capabilities. We assume a high definition video with a resolution of \(1280\times 720\) pixels, a frame rate of 30 Hz, 24 bit color depth, and a typical compression of 1:30 (e.g., with H.264 codec, extended profile [19]), as we need advanced capabilities for the extraction of video features in real time. This results in a data rate of up to 10 Mbps (cf. Table A-1 in Annex A of [19]). Only the relevant sections of the video are transmitted, resulting in an expected data rate of 2 Mbps, in order to reduce the data rate.