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Tools of the Trade / Re: Using VoIP/PBX for Comms + streaming video relays
« on: Apr 03, 2011, 10:58 am »
The main developments in VoIP (or rather SIP) based comms is actually in the higher end, rather than the lower end of the comms spectrum. I am mainly talking about matrix comms systems, like those used in TV and large broadcasts...
The standard coms beltpack forms part of what is commonly known as a "Two-wire Partyline" (yes there, are three wires in the XLR, but only two "matter") - a number of different types of TW-PL's exist, RTS and Clearcom are the major standards, and to an extent you can mix and match some beltpacks with different masters etc (occasionally).
Many theatres run a number of "loops" - and use base stations with the ability to handle 1 or more loops each. Once you get beyond 3 or 4 loops, it starts to get unwieldy, as each loop that a base station can use needs it's own cables.
So the next jump up is a matrix comms system, and it is a big jump. In a TW-PL system whilst there is a master station (which can either be a user station or just a power supply), it can be anywhere along the comms line, and that line can be split in many places and looped through the beltpacks. A matrix system is a lot stricter. You have the matrix "Frame". It sits in the middle and has a whole bunch of outputs on it (ports). A station (panel) connects to a port. 1:1. You cannot daisy chain or anything like that. One panel, one port. So you end up with a big star.
The panels are literally rack panels with a whole bunch of buttons or switches on them. The comms engineer can configure these to allow you to talk to another panel, or to listen to a panel (so you choose who you hear, unless someone has something they want to say to you). They can also set up partylines within the system as well as a number of other features. This is then usually integrated with TW-PL systems, often a couple of phone lines as well, and sometimes two-way radios as well. They are hugely complex beasts.
Since these are often used in broadcast and other multi-site operations, frames often have the ability to link to other frames and do really cool things to make multiple sites able to talk to each other, almost as if they were on the same system - it's called Trunking. This is where they are starting to use VoIP - because by doing this they can allow a one man site (say a guy in a sat truck) to join the net, and suddenly be linked into the studio comms.
A reliable (wireless) VoIP system will cost you more to set up than a wired coms system. Wired... that is possible to do - and if you invest the time, you could make a very usable VoIP system, but it will take a lot of configuration.
The standard coms beltpack forms part of what is commonly known as a "Two-wire Partyline" (yes there, are three wires in the XLR, but only two "matter") - a number of different types of TW-PL's exist, RTS and Clearcom are the major standards, and to an extent you can mix and match some beltpacks with different masters etc (occasionally).
Many theatres run a number of "loops" - and use base stations with the ability to handle 1 or more loops each. Once you get beyond 3 or 4 loops, it starts to get unwieldy, as each loop that a base station can use needs it's own cables.
So the next jump up is a matrix comms system, and it is a big jump. In a TW-PL system whilst there is a master station (which can either be a user station or just a power supply), it can be anywhere along the comms line, and that line can be split in many places and looped through the beltpacks. A matrix system is a lot stricter. You have the matrix "Frame". It sits in the middle and has a whole bunch of outputs on it (ports). A station (panel) connects to a port. 1:1. You cannot daisy chain or anything like that. One panel, one port. So you end up with a big star.
The panels are literally rack panels with a whole bunch of buttons or switches on them. The comms engineer can configure these to allow you to talk to another panel, or to listen to a panel (so you choose who you hear, unless someone has something they want to say to you). They can also set up partylines within the system as well as a number of other features. This is then usually integrated with TW-PL systems, often a couple of phone lines as well, and sometimes two-way radios as well. They are hugely complex beasts.
Since these are often used in broadcast and other multi-site operations, frames often have the ability to link to other frames and do really cool things to make multiple sites able to talk to each other, almost as if they were on the same system - it's called Trunking. This is where they are starting to use VoIP - because by doing this they can allow a one man site (say a guy in a sat truck) to join the net, and suddenly be linked into the studio comms.
A reliable (wireless) VoIP system will cost you more to set up than a wired coms system. Wired... that is possible to do - and if you invest the time, you could make a very usable VoIP system, but it will take a lot of configuration.