The media industry is accustomed to plug-and-play devices thanks to technologies like USB and HDMI. These technologies ensure that send and receive functions “just work” when two devices are connected. Plug and play is certainly easier than using serial ports which require you to set the data rate, data bits, parity, stop bits and flow control at each end and also make sure they match before you can connect two devices together. The whole idea of plug and play is to take the burden off of the user and leave it up to the devices to determine how to talk to one another.
Let's explore how plug-and-play benefits different media system workflows, including SDI, media over IP, and SMPTE ST 2110.
SDI systems have some level of plug-and-play support. For example, smarter devices can determine what type of SDI signal they are receiving (i.e., SMPTE ST 259, 292, etc.) and adjust to process the signal appropriately. It is worth noting that an SDI router has no awareness of whether connected receivers are smart enough to auto-detect the incoming signal. Whereas, the routing control system needs to have that awareness.
It would be considerably easier for for media over IP solutions to set up and maintain systems if devices offered plug-and-play behavior. However, there is a fundamental difference between connecting a cellphone and laptop versus connections to a production system that may feature devices from multiple vendors. In the latter case, there is no 1:1 relationship. Media over IP deals with a one to many approach. For example, video, audio and data available as multicast from any number of senders that can be picked up by any number of receivers on the network. So what should you do? Since media over IP is not a 1:1 approach, it requires a certain level of management to keep track of which senders and receivers are available, and what each support.
In the case of SMPTE ST 2110, plug-and-play behavior is not defined. Used in isolation, the control system needs to determine the configuration of each sender and receiver on the network in order to ensure that only valid flows are connected between devices. This results in a laborious, manual process. So, what’s the solution? To help advance the cause for faster setup and error-free connection of devices, AMWA created the IS-04 (discover and registration) and IS-05 (connection management) specifications. These two specifications are gaining traction amongst vendors supporting SMPTE ST 2110. The result is that compliant devices can be found easily on a network and queried about their available flows. The control system can centrally store and access this information. If a device drops off the network, it also drops off a list of available senders/receivers. Since the control system determines which flows are connected between senders and receivers, it empirically knows whether two devices can be connected, thus creating the desired plug-and-play behavior in a complex network of devices.
When you are setting up a system for the first time this approach to plug and play is particularly helpful. It is also extremely useful when you need to take devices offline for upgrades or replacement, or if devices fail. The control system will know when senders and receivers come and go from the network. It also saves you time in environments that change over time — whether through upgrades, expansion or contraction in the number of devices and flows in the system.
The SMPTE ST 2110 suite of standards is a great solution to the complex needs of producing, playing out and delivering video, audio and data in today’s modern world. It's much faster and simpler to integrate when you choose devices with plug-and-play support.