Gizmocoding Forums

Hi

1.
Short answer = No that is not possible.

Basically each camera is completely seperate thread and there is no communication between. They all run completely independently - so one signalling the other to start etc. isn’t really going to be possible, without destroying this aspect which is pivotal.

2./
There is something else going on with your setup.

The bandwidth of wifi is not saturated until the 866Mbps is reached - so I would be gathering something else is going on.

Few thoughts would come to mind:

- Setup a different SSID (same AP) for each camera on a different channel. This would overcome any of the issues you describe if real. Most APs enable multiple SSIDs.

- Change one of the Dashcam’s to 2.4 ghz wifi - whilst max is slower may not see much difference and would overcome any wifi issues.

- Check the current SSID channels for interference from other networks and change the channel for it.

- Block both cameras from connecting to cloud at router/ip level. We have found that this competes with wifi transfers (obviously) and considerably slows down because of SD-card hammering.

- Check your storage media that is saving files to - presumably the same HDD is used for both camera and this may be the point of difference between running one camera and running 2.


Glenn


Sent from my iPad using Tapatalk

The bandwidth of wifi is not saturated until the 866Mbps is reached - so I would be gathering something else is going on.

The “bandwidth of WiFi” is rather an abstract concept that NEVER gets utilized 100% by any device, even a single one.

In order to fully saturate an 866 connection, you would need at a minimum two AC-866 capable devices connected and transmitting at 100% rate (they can only upload at 433Mbits each). Whenever the radio switches from one device to the other, there is a performance loss and time is wasted. An AC radio can only talk to a single device at the time and takes time switching from device to device to serve all. The airtime fairness (how much time the router dedicates to each client) is not normally a configurable option in any device and is done automatically by the device and following the applicable Wi-Fi standard.

Any AC 866Mbits capable device will in fact connect to the AP at a max theoretical speed of 433Mbits per direction because the bandwidth is symmetrical and gets split equally between download and upload. It may say “connected at 866MBits”, but that’s not what really happens. You don’t get the whole 866 in a single direction.

It would be awesome if we could adjust those ratios to 90% download and 10% upload, but that’s not how wireless technology works. If the device is not uploading, that bandwidth is “wasted”, cannot be reassigned to the download portion.

When I finished installing all the setup and found myself with speeds of no more than 25MB/s I also thought something must be wrong but in fact, that wasn’t the case. The speeds I’m getting are the typical speeds.

AP 866
Device: 433 ---> 216.5 UP/216.5 DOWN = 27MB/s theoretical in either direction.

If you add a second device, also 433, those speeds get halved automatically. Now I have 13.5MB/s for each device.

Now the AP has to distribute bandwidth equally between two devices. Each device will get no more than 216.5Mbits in either direction, regardless of how much extra “room” the AP may have.

There is nothing else using the extra bandwidth that the AP can handle. That extra capacity is “wasted” and cannot be used by devices not equipped to use it.

- Setup a different SSID (same AP) for each camera on a different channel. This would overcome any of the issues you describe if real. Most APs enable multiple SSIDs.

This is technically impossible. An AP may have one or several SSIDs, but the RADIO those SSIDs are operating on will be exactly the same. You cannot setup one SSID to work on one channel, and then a second SSID to work on another channel, on the same band. You would need a multi radio router or AP for that and one that would have a radio for each channel. Normally, a router or AP will have one radio per band, and that radio will be working on ONE or several combined channels in the case of AC or AX.

Whatever channel the AP radio is set to, that’s the channel that all SSIDs will share, even though logically separated. Your main SSID and your guest SSID are both working on the same channel and there is no way to split them.

- Change one of the Dashcam’s to 2.4 ghz wifi - whilst max is slower may not see much difference and would overcome any wifi issues.

This one is a valid proposal. I could try that.

- Check the current SSID channels for interference from other networks and change the channel for it.

I did that at setup. Chose the best channel available with least interference.

- Block both cameras from connecting to cloud at router/ip level. We have found that this competes with wifi transfers (obviously) and considerably slows down because of SD-card hammering.

Not sure I follow you on this one. I don’t upload anything to the cloud. There should be one single read thread coming from the SD when I’m downloading the footage.

- Check your storage media that is saving files to - presumably the same HDD is used for both camera and this may be the point of difference between running one camera and running 2.

This wouldn’t be a factor. Data is transferred to an NVME drive that can sustain astronomical write speeds.

The bottleneck here is the factory WIFI card inside the cameras that is restricted to single channel Wireless AC. A single channel AC device cannot benefit from the MIMO of 866. The SD card itself can handle 85MB/s read/write on a USB3 reader. I honestly don’t know why Blackvue decided to cripple their flagship product with such a hideous sub performing wireless interface. A 4K camera needs all the speed it can get, and more.