A video conference is a live, visual connection between two or more people residing in separate locations for the purpose of communication…At its most sophisticated, it provides transmission of full-motion video images and high-quality audio between multiple locations.
What is video conferencing and how does it work?
To set the foundations for future elaboration, at the simplest level, a video conference is an online meeting (or a meeting over distance) that takes place between two parties, where each participant can see an image of the other, and where both parties are able to speak and listen to the other participants in real time. The components necessary to make this happen to include A microphone, Webcam, speakers and a display.
A software program that captures the voice stream from the microphone, encodes it, transmits to the other participant, and simultaneously decodes the digital voice stream being received from the remote participant in the video conference (most commonly referred to as a “Codec”).
A software program that bridges both parties together across a digital connection, managing the exchange of voice and video between participants. At either end of the connection, the video and voice traffic is combined and delivered to each participant in the form of a real-time video image and audio stream.
An optional management tool for the scheduling of video conferencing sessions:
At a slightly more advanced level, it is also possible to provide the ability to share content from a device during a video call. The quality and type of content that can be shared depends on the rate of data exchange during the call.
The terminology used by video conferencing users to describe the process of dialing into and participating in a virtual meeting is known as “joining a bridge.” Different virtual meeting rooms are assigned unique “bridge numbers,” and users join a video call by “dialing a bridge number.”
Point-to-point video conferencing:
Point-to-point video conferencing Video-enabled meetings happen in two distinct ways: either point-to-point or with multi-point. In point-to-point, the simplest scenario is where one person or group is connected to another. The physical components (i.e. microphone and camera) that enable the meeting to take place are often integrated into to desktop computing solutions like a laptop or tablet or can be combined into dedicated, room-based hardware solutions.
In multipoint video calls, three or more locations are connected together, where all participants can see and hear each other, as well as see any content being shared during the meeting.
In this scenario, digital information streams of voice, video, and content are processed by a central,independent software program. Combining the individual participant’s video and voice traffic, the program re-sends a collective data stream back to meeting participants in the form of real-time audio and video imagery.
Individuals can participate in a meeting in an “audio only” mode, or combine audio with video images of the meeting on screen. Depending upon the technical capability of the video conferencing system being used, images seen by participants are either classified as “active speaker” or “continuous presence.”
In “active speaker” mode, the screen only provides an image of the person that is speaking at any point in time. In more advanced solutions with “continuous presence” mode, the bridge divides the image on the screen into a number of different areas. The person speaking at any point in time is presented in a large central area, and other meeting participants are shown displayed around the central image.
The language of video conferencing :
As video conferencing technology has evolved, two main protocols have emerged to provide the signaling control for the establishment, control, and termination of video conferencing calls: SIP (Session Initiation Protocol) and H.323.
For the encoding and decoding of visual information, the industry is moving towards the industry standard known as H.264, which was developed to provide high-quality video at lower bandwidth over a wide range of networks and systems. An extension to the H.264 protocol is Scalable Video Coding (SVC), which is established to facilitate the enablement of video conferencing on a wider range of devices, such as tablets and mobile phones.
Bridging architecture and functionality:
The combination of software and the hardware that creates the virtual meeting rooms is called a “video bridge.” Virtual meeting rooms are identified by their “bridge numbers.” With multiple calls taking place simultaneously, software analyses all the different data streams coming into the bridge processors and assigns data streams accordingly.
At the simplest level, the processing workload for bridges is dependent upon four factors:
- The number of locations that dial into each bridge
- The number of conferencing calls that each bridge must handle simultaneously
- The amount of data that is being received on each digital stream: higher resolutions of images and sound (i.e. High Definition) generate more data that needs to be processed
- The degree of transcoding that the bridge must perform while handling calls being received at different connection speeds and utilizing different protocols
Video call management and protocol conversion:
In order to build an architecture that scales, the software platform must be able to provide call signaling functionality, and dynamically manage the set-up and maintenance of a large number of video calls. The software architecture has to be capable of reconfiguring itself and its resources in real-time so that these resources are used to their best ability. In addition, the software architecture has to understand the bandwidth requirements of each call being placed, the policy that is associated with each call (the prioritization and importance of a call), and where the participants of a call are geographically located. By understanding this, the software platform can utilize local resources instead of redirecting data streams and call signaling to resources that are far away, an approach which would eat up large amounts of bandwidth on WAN links that are very costly.
To enable large-scale deployment and management of video conferencing solutions, the software platform provides for the management and maintenance of hardware infrastructure components through a separate functional area: The Device Manager. The Device Manager can help dynamically provision devices and components of the video conferencing infrastructure. Once the component hardware is deployed within the network and its infrastructure, the Device Manager will monitor and help troubleshoot problems with these devices. When software updates are required, the Device Manager will help deploy them.
Many organizations who have invested in video conferencing will inevitably need to be able to assist mobile or home workers wanting to dial into their company network and participate in video calls with colleagues. The software platform must, therefore, provide the capability to enable, and manage this. Likewise, video conferencing-enabled organizations will also want to use the technology to communicate with their partners and customers. This will only be possible if video traffic is able to securely traverse the firewalls from one customer to another. Firewall traversal is a particular challenge to video, as the data firewalls try to reorganize data packets.
Historically, the primary motivating factor for most companies has been to use video conferencing as a way of saving business travel costs. Recently, organizations are beginning to understand that the benefits of video conferencing can impact many different parts of an organization including; training, marketing, education, compliance, internal communications, advertising, PR, to name just a few. As the usage of video conferencing in these fields has begun to grow, customers have discovered the potential to not only use video conferencing to communicate in real-time but also to uncover the possibilities that exist for reusing digital recordings of past events and communications. Moving beyond “meetings,” the same technology is being used to create digitally encapsulated rich media, which can then be edited, enhanced, archived, and broadcast across multiple media. These assets can be made available to target audience’s on-demand.
Live event multicasting–The software platform enables the streaming of recorded webcasts, and supports both the push and pull of video to the streaming servers.
Video-on-demand-The software platform automates the creation of archived versions of any live event webcast so that customers can replay them on demand, as desired.
Media management–The software platform can be used to control how video content will be aggregated, approved, categorized, edited and published.
Storage and archiving–The software platform establish rules for the lifecycle of storage for bandwidth-intensive video content: customers can determine how the content will be retained, transcoded and stored in the Cloud, or across corporate resources without daily, hands-on maintenance.
There are a number of different ways of sharing data and collaborating on applications while taking part in a video conference. Many of these are proprietary, and often have the drawback that they share the data in-band using valuable bandwidth (and computing resources) that would otherwise be available to the video and audio data.