Figure 1: Automotive BroadR-Reach Ethernet HD cameras from two different manufacturers.
Set-up of network, data traffic and timers
The following three video clips show how the system is setup:
Video clip 1, 2 and 3 (1-2 mins each)
Video clip 4 - run simulation
A look at the colourful Task Gantt Chart gives you an idea of how much data the system is pushing and the order of it.
Second simulation - change cameras
There are different ways we can try to solve this problem; The first alternative in trying to avoid dropped frames is to keep the 100 Mbit/s switch port but instead replace the cameras to a "model B" that uses a more efficient compression method (i.e. H.264) with a lower bandwidth requirement. This is done by simply changing the camera (sensor) type to "custom" and choose a previous recorded video data file from a "model B" camera.
The Task Gannt Chart provides you with the opportunity to drill down and examine the timing behavior.
Third simulation - remove a camera
At least one camera has to be removed in order to avoid too many dropped frames. In addition, one of the remaining cameras might do the job with a lower resolution setting (640*480):
Video clip 6 - remove one camera, change another to low resolution
There are still a few dropped frames. The results indicate that the limit of the 100 Mbit/s switch capability are reached and we must consider changing to another switch with larger switch port memory buffers.
The latency distribution has changed significantly:
Fourth simulation - introduce 1 Gbit/s
If we need to keep four high resolutions cameras, we have the option to use a bandwidth rate of 1 Gbit/s at switch port 5. The following video shows how to change the original topology to a switch port bandwidth setting of 1 Gbit/s.
(Note: This shows the advantage of simulation of not yet released or available real world physical hardware. 1000BASE-T1 technology is not yet available, or at least hard to get hold of.)
Video clip 7 - change switch port settings