Crestron NVX over wireless

  • 9 March 2018
  • 4 replies

Userlevel 6
Has anyone run video from an Crestron NVX over wireless? We have a new building with a room that's going to have some projectors, and then some mobile pods for students, with NVX-350 encoders on the pods and NVX decoders (via a matrix switch) to the projectors, so a students' work can be projected easily. There's also an NVX receiver on each pod so the teacher can push out content. Since they're mobile, the video traffic will have to go over wireless, I'm thinking of putting a mesh AP with Bridge to LAN on each pod.

The challenge comes from two things - bandwidth and multicast. The specs say the video bandwidth can range from 100Mbps to 990Mbps - we'll only be doing 1080p video, not 4k HDR, so it'll probably be at the lower end of that. The video is transmitted as multicast, which might be OK for sending to the pods if adaptable rate multicast is enabled, but I'm wondering about sending from a pod with a mesh AP - will the infrastructure AP have to rebroadcast the multicast out again, doubling the airtime? Or should I get client bridges instead of meshing? 80MHz channels in DFS space (which I don't otherwise use) with 4x4:4 APs/clients and 24Mbit MBR (ie MCS3) should give me a minimum data rate of 520Mbps, which makes 100Mbps real traffic seem feasible, and I would think I should be able to get MCS7 being in the same room, which would push me to 1300Mbps theoretical. And perhaps have two APs, one on each 80MHz DFS channel.

Is this feasible? Does anyone have any experience with doing this?

Relatedly, they also want some more ethernet on the pods for control traffic. For that I was thinking 3912 APs, how do the wired ports on that work when it's being a mesh AP?

4 replies

Userlevel 6
I don't think I can use Identifi APs as a client bridge, but could I use a WiNG AP 8432 or 8533 (which are the only 4x4:4 WiNG APs right?) as in client bridge mode? All I can find is this GTAC KB which talks about 75xx and 76xx, but doesn't mention 8xxx at all.
Did you try this yet? I am guessing latency may be an issue with WiFi. Traditional WiFi is also half duplex, so you may need to look at full duplex WiFi systems.
Userlevel 6
Did you try this yet? I am guessing latency may be an issue with WiFi. Traditional WiFi is also half duplex, so you may need to look at full duplex WiFi systems.I did, using a 7532, however I hit a bug where it was unable to associate at 802.11ac rates and bandwidth in client bridge mode, and 802.11n wasn't fast enough - the image would get about half-drawn then it would start again. GTAC reproduced it, was supposed to fix it but didn't, the case (01707862) is currently escalated to engineering.

My fallback plan is Ethernet over Power - I'm going to get some AV2 2000 adapters, TP-Link TL-PA9020P are apparently the best performing.
If you power crestron NVX units over lan we have used the MicroSemi PD9524GACDCMUS recommended by Crestron in two large scale installs successfully. This poe injector however can only provide power for around 20 nvx devices over lan even though though it has 24 ports. NVX devices draw around 35 watts at the device therefore you will need something that provides 802.3bt Type 3 "PoE++ or 4PPoE" (51.00 watts at powered device)for stable performance. You can power the devices on with standard PoE+ but you will have continual failures and non operations - it will just look like it is working.