weConnect - Overview of network connections and bandwidth loads

Article number: [2794] - Legacy code: [7706]

Applicable to

This information is important to understand in order to assess the impact on the wireless network and the impact on network bandwidth needs between networks or switches and to/from the internet.

Network traffic between BYOD and Barco components

Data plane

Students who get the live preview option in the student interface will ingest around 1Mbps to their personal device (BYOD).

Media plane

 

For teachers, the average preview bandwidth is higher (Content A in the illustration above) than for students as the update rate is higher.

The bandwidth required for mirroring devices depends on the resolution and the amount of change in the image.  On average the bandwidth for teacher content like presentations is minimal: close to 100kbps with short peaks of several Mbps when content changes.  For full screen video mirroring at full resolution, the bandwidth can peak as high as 15Mbps, but mostly it will average 2-5Mbps.  For network sizing purposes, we recommend to take 4Mbps as the average bandwidth requirement for each concurrent mirroring in the classroom.

To know the average across a range of classrooms in an institute it is best to multiply the 4Mbps with the amount of Display Nodes in the institute to know the average bandwidth requirements across a complete network.

Overflow room scenario

For remote learning scenarios where all content stays on the institute network up to 4 AV streams can go bi-directionally between the classrooms.

For standard remote learning scenarios 2 bi-directional AV streams have to be taken into account when connecting only two classrooms.

Virtual classroom

Calculating the bandwidth for Virtual Classroom setups or for individual remote users connecting over an internet connection.

The virtual classroom use case generates multiple media streams which are available to all participants.  In return each participant sends media streams back to the virtual classroom to support the full bidirectional nature of the use case.

·    Classroom side

  • Upstream bandwidth
    Only one set of streams consisting of the teacher content, teacher audio, all camera streams (teacher cameras and tile cameras) and all preview streams get uploaded into the cloud.  Additionally the individual participant audio mixes get sent to the cloud.
    The total bandwidth for any size of Virtual Classroom stays under 10 Mbps for the teacher content and room camera streams. Per participant an additional 1Mbps bandwidth is used for the individual audio content and tile camera feed.
    For a 24 seat room used at maximum capacity the total upstream bandwidth to be reserved is 10Mbps + 24x1Mbps, resulting in 34Mbps. For an 80 seat room, a bandwidth of 90 Mbps is required for an ideal experience. Note that the tile camera feed is always uploaded, even if there is no student on the tile.
  • Downstream bandwidth    
    Under perfect conditions the downstream bandwidth is between 1 Mbps and 3 Mbps per participant. E.g. a 24 seat room uses up to 72Mbps. This is if no participant is sharing content!     

Participant side

  • Upstream bandwidth
    Between 1 and 3Mbps for participant audio and video, and potentially shared content.
  • Downstream bandwidth
    2-4 Mbps for the various content and camera sources and incoming audio streams.

The system supports internet connections which do not have guaranteed bandwidth availability. Temporary low bandwidth conditions get dynamically absorbed by the system and are causing media streams to be reduced in bandwidth. The system prioritizes audio over video and will as such first reduce video quality and frame rate. On extreme low bandwidth connections the video content can be fully disabled only retaining the audio connections.  As soon as bandwidth limitations are lifted the system recovers to provide the maximum possible media quality at any time.

 Please contact our support team to get a precise estimate of bandwidth usage of your virtual classroom. weConnect has many options & parameters that can make the bandwidth vary quite a lot.

[KB7706]

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Last updated Jun 14, 2022