The main problems of using video communications in meeting rooms and their solution
Last time, we talked in detail about various video conferencing equipment for meeting rooms.
In this article we want to talk about the most common problems that arise when equipping and using meeting rooms. Very often they are the reason for the low productivity of negotiations.
So let's take a closer look at them:
Consider these problems and their solutions in more detail.
The solution of difficulties with the perception of the voice of the interlocutors is the primary task in the design of the meeting room under the videoconferencing. The consequence of these problems may be poor audibility of remote participants and the illegibility of their speech. People have to ask each other more than once and ask them to repeat what was said. This leads to discomfort in communication, unproductive negotiations and quick fatigue of participants.
The most common sound problems:
These include design errors in the meeting room that interfere with the quality of video capture and display.
This includes problems associated with the video channel: insufficient bandwidth, a high level of packet delays, Wi-Fi connection, lack of prioritization of traffic, etc. The more of the following recommendations your network administrator can provide, the better video quality you will get.
It is not always possible to design a meeting room “from scratch” at the stage of its construction. Often, meeting rooms become rooms adjacent to the common office space or vacant utility rooms with all their features. This article talked about ways to solve the most common problems.
We will be glad if in the comments to the article you share your experience or tasks that you would like to solve, and we can advise you on how to solve them.
In addition, you can turn your task directly to the author of this article, Tatyana Usikova
In this article we want to talk about the most common problems that arise when equipping and using meeting rooms. Very often they are the reason for the low productivity of negotiations.
So let's take a closer look at them:
- Acoustic problems - all problems associated with the quality of capture and playback of sound.
- Lighting problems - lighting problems, such as interior decoration, the use of low-quality video cameras.
- Communication problems - lack of prioritization of video communication traffic on network equipment, connection of a video conferencing terminal via WiFi / 4G, load from network users.
Consider these problems and their solutions in more detail.
Acoustic problems
The solution of difficulties with the perception of the voice of the interlocutors is the primary task in the design of the meeting room under the videoconferencing. The consequence of these problems may be poor audibility of remote participants and the illegibility of their speech. People have to ask each other more than once and ask them to repeat what was said. This leads to discomfort in communication, unproductive negotiations and quick fatigue of participants.
The most common sound problems:
- The echo effect is a situation when a conference participant hears a speech along with the speech of remote opponents. The echo effect occurs due to the fact that the participants' speech reproduced in the speakers of the far side is returned through their microphone. To compensate for the echo, there are software and hardware solutions called echo cancellers. Echo cancellation is the process of recognizing the initially transmitted signal, repeated with some delay, in the transmitted or received signal. Once a repeating signal is recognized, it is removed by subtracting it from the transmitted or received signal.
Most video communication software clients (Skype, Trukonf, etc.) have either a built-in software echo canceller or automatic microphone sensitivity correction in their settings to compensate for self-excitation.
Software echo cancellation does not always solve the tasks, because there is a need to use more efficient hardware echo cancellers due to the presence of specialized DSP-processors for processing audio signals.
For small meeting rooms, for example, the Phoenix Audio MT107 professional echo canceller is an excellent solution . For large meeting rooms, when you need to mix several sources of audio signal (from two to four), Phoenix Audio Octopus is ideal , which, among other things, has a built-in audio amplifier for the speaker system.
The general scheme of operation and connection of an echo canceller using the example of Phoenix Audio MT107 is shown in the following figure:
- Noises. In our case, these are extraneous sounds that are not related to the speakers ’speech: man-made noises (air conditioners, equipment fans), paper rustling, chairs moving away, coughing, etc.
Conferencing microphones are focused on the human voice, that is, on capturing sound waves in a certain frequency range. Suddenly arising noise is knocked out of the frequency response of human speech, and the noise reduction system tries to cut it out from the general audio stream.
The solutions described above: MT107 and Octopus , in addition to echo cancellation, are effective noise reduction systems. - Feedback acoustic communication. If in the meeting room the speakers are located above the microphones or directed towards them, then when you turn on several microphones, there is a high probability of sound pickup, because the microphones will amplify the sound coming from the speakers and self-excite.
To combat this local phenomenon, acoustic feedback suppressors are used .
The principle of their work is as follows: the feedback suppressor determines at which level of frequencies pickups begin to occur and as soon as these frequencies “creep” upwards, it cuts them out.
The general scheme of operation and connection of an acoustic feedback suppressor using the DBX AFS2 as an example is shown in the figure:
- Low audibility. It consists of two factors: the use of insufficiently sensitive microphones and sound systems of insufficient power.
Consider the first option with a specific example. A video-conferencing hardware terminal (Polycom, Cisco, etc.) with a standard microphone is installed in the meeting room. Suppose that his sensitivity is not enough to cover all the people present in the room, and the hardware terminal does not support the connection of more than one regular microphone.
A solution to the problem could be to connect third-party microphones to the VKS terminal through the 3.5-mm mini-jack connector, which is even on the very youngest models in each terminal.
It can be a wired or wireless congress system. The congress system is especially relevant when there are more than 10 participants in a room.
Instead of a congress system, an audio mixer can connect a desktop or ceiling microphone system to the VKS terminal.
From desktop microphones , ravens are suitable for this task , which are connected to the hardware terminals through a mixer and an echo / noise canceller [Octopus].
An excellent working option for ceiling microphones is the Biamp Devio CR-1C , which consists of a high sensitivity ceiling microphone and a central unit.
Sound systems of insufficient capacity give poor audibility to distant participants. For example, when using the built-in TV speakers in a large room. In our experience, it is advisable to use the built-in television speakers in rooms with an area of not more than 20-25 sq.m.
In larger rooms, the sound from the TV speakers is scattered as the distance from the TV is between people sitting. In this case, we recommend using:
Ceiling or wall speakers with an audio amplifier. Speakers
built into speakerphones .
In both cases, the sound source is closer to people and, therefore, the interlocutors are heard better. - Adverse acoustic conditions due to the presence of a large number of sound-reflecting surfaces in the room, such as glass walls, tables and other interior elements.
In this case, we recommend using congress systems for the best sound capture . they are equipped with microphones with a narrow pattern. Due to the narrow focus, the microphone picks up only the speaker’s voice, and all extraneous sounds that go beyond the boundaries of the radiation pattern are cut off.
Also in such adverse acoustic conditions, microphone arrays have proven themselves well:- Audio Phoenix Condor with intelligent adaptation of the voice volume level depending on the distance of the speaker from the microphone array.
- Shure Microflex Advance MXA910 with automatic mixing, frequency correction and echo reduction features.
Architectural solutions help to partially absorb the reflected sound - fabric blinds on the windows, sound-absorbing flooring, sound-absorbing panels. - Audio Phoenix Condor with intelligent adaptation of the voice volume level depending on the distance of the speaker from the microphone array.
Lighting technical problems.
These include design errors in the meeting room that interfere with the quality of video capture and display.
- Incorrect lighting. It is not recommended to use fluorescent lamps and spotlights in the premises for VKS. This leads to uneven lighting and flickering of the image received from the cameras. The second is sometimes solved by the flicker compensation functionality built into professional VKS cameras of flicker 50-60 Hz. But it is almost impossible to compensate for the dimming and flare zones with camera functionality. As a result of improper lighting, the camera will try to work out areas that are too dark or now highlighted - this can lead to frequent refocusing and a change in the overall brightness of the picture.
The solution to such problems is the use of scattered light on the basis of LED lamps, evenly distributed over the ceiling of the meeting room in the area of the table for negotiations.
It is also necessary to avoid back or side illumination, sunlight from the windows on the faces and in the camera lens.
Offhand, you can evaluate the quality of lighting by looking at the meeting room through the camera of a mobile phone in the video mode - this will reveal the main problems with flickering light, sharp contrast and focusing. - Non-optimal interior colors and background. The wall opposite the camera is an important detail in the design of the meeting room. It is better to place a company logo and a clock showing the local time on it. In the decoration of the room it is better to avoid colorful colors, black and bright white, complex patterns in the interior. All this can prevent the camera from focusing and distract participants from the speaker.
- Non-optimal video display and capture devices. When designing display tools, it is better to exclude the use of projectors, as they are more suitable for presentations. In order to provide the necessary brightness and contrast, it is necessary to dim the light in the room. Whereas during video conferencing it is necessary to provide high quality images with good illumination of the room, which is required for high-quality video capture. Given these requirements, it is best to use LCD TVs, video walls, or interactive video panels .
- As a means of capturing video, it is recommended to use professional cameras for videoconferencing. They have the necessary qualities for working in meeting rooms and conference rooms. Among these qualities are high photosensitivity, tilt / rotate / zoom functionality, built-in image correction functionality, as well as a function to automatically aim the camera at participants. Webcams are best left for personal use, and even more so you should avoid using cameras built into mobile devices or laptops in meeting rooms. The quality of the picture from such cameras will make communication uncomfortable and unpleasant for your opponents. Those who participated in such a group conference on Skype from a laptop will understand me. It’s almost impossible to understand which group is talking to you right now - the picture is fuzzy, voices are indistinguishable. And this despite the fact that the image was broadcast on a 55-inch panel a meter from the table.
Communication problems
This includes problems associated with the video channel: insufficient bandwidth, a high level of packet delays, Wi-Fi connection, lack of prioritization of traffic, etc. The more of the following recommendations your network administrator can provide, the better video quality you will get.
- Using Wi-Fi wireless. The videoconferencing terminal in the meeting room must have a wired network connection. Although in fact, often under the table in the meeting room there is no network cable or a power outlet for it.
- Video and audio traffic is critical to data packet delays in the communication channel. Therefore, you need to provide a QoS policy by placing VKS traffic on a separate subnet or VLAN. You also need to configure prioritization and labeling of video conferencing traffic so that it is transmitted first of all, and requests from browsers, email clients, and other traffic not critical to delays have a lower priority. For example, configure Priority Queue for real-time RTP traffic, as well as for signaling traffic that uses specific ports: 5060 UDP in case of [SIP] or 4307 [TCP] if you use TrueConf .
- Refuse asymmetric Internet connection in favor of symmetric. An asymmetric connection, including ADSL, when the incoming speed is much higher than the outgoing, can cause poor quality of communication for your interlocutors.
- Provide high availability and better connection speed for a group video conferencing server or MCU. Outgoing traffic on the server during conferences significantly exceeds incoming traffic. Therefore, it makes sense to place the server in a good data center with a gigabit Internet channel, connecting it to your VPN network to guarantee a good connection to the server for all conference participants. By the way, the TrueConf videoconferencing server for these purposes has a special version in the Amazon AWS Marketplace application store.
- Use modern solutions for videoconferencing, as they will be able to quickly adapt to changing connection conditions and will be able to “break through” NAT and Firewall.
conclusions
It is not always possible to design a meeting room “from scratch” at the stage of its construction. Often, meeting rooms become rooms adjacent to the common office space or vacant utility rooms with all their features. This article talked about ways to solve the most common problems.
We will be glad if in the comments to the article you share your experience or tasks that you would like to solve, and we can advise you on how to solve them.
In addition, you can turn your task directly to the author of this article, Tatyana Usikova
usikova@unitsolutions.ru, and get not only professional advice, but also a discount on equipment for the unitfix promotion word .