High Speed, High Quality, Low Cost IP Links
February 7, 2013 / Broadcast Technology/
I recently had the opportunity to be the tech for an outside broadcast from a live outdoor concert and festival. It was a fairly standard arrangement with a split from the PA, stereo pair of Rode NT5‘s as atmos mics, and a pair of Rode Procasters for announcers and interviewees.
In the past I’ve used 3G, 4G, ISDN, and even POTS links to get the audio back to the studios. The unique thing about this broadcast was that we were located about 200 meters from the station’s studio complex. This mean that I had the opportunity to try out a pair of Ubiquiti NanoStation Loco M5‘s as the backlink for the IP audio. These are really nice little units, and provided a very solid IP connection directly into the station’s LAN. Not only could we run IP audio over this, but we could also directly access the playout server and computers.
If you are unfamiliar with the Ubiquity range, you should acquaint yourself with them immediately. These products are both brilliant and cheap (cheap as in price, not cheap as in quality). My particular model cost about AU$70.00 each, plus shipping and the local power cable. They operate on the unlicensed 2.4Ghz or 5Ghz range. If you’re after more serious point to point links, they also offer dish antennas for highly directional coverage. I am aware of stations using these as their main studio-transmitter link in a sizeable Australian east-cost city (this was discussed at the Technorama conference in 2012).
I was able to attach one unit to the station’s tower outside the studio at about roof level. The other one was cable tied to one corner of the marquee we operated out of. In between were a couple of trees and at least one large marquees. Despite this, I was able to get a consistent 70Mbps across the link. Given that I only really needed 2Mbps for the audio, this was more than enough. Oh, and I should mention that I didn’t really have to perform any antenna alignment, which proved this to be one of those rare situations where near enough is good enough.
There were absolutely no configuration tricks to get these units working. I just followed Ubiquit’s video instructions. I let it automatically select a channel and channel width, and manually set the correct IP addresses. Doing a channel scan revealed nothing else happening on any of the 5Ghz channels (it seems most consumer equipment in the area is only running in the 2.4Ghz range).
This setup worked extremely well, and I was pleasantly surprised (although not shocked – testing the day before was very positive). We connected the Tieline G3 iMix using PCM as the codec with very low error correction and buffering. Over the six hours or so we were connected, I only experienced a single audio ‘glitch’. Thankfully we were playing content from the studio’s computer at the time so no artefacts were broadcast, and the Tieline got back up to speed within seconds. I’m unsure as to the cause of this momentary loss of connection, as it could have been issues anywhere on the LAN or the Ubiquiti links.
Doing some extra driving around the surrounding streets revealed exceptional coverage. I could get reception at about 180° off the front panel. I was able to drive about 600 meters down the road and get decent speeds from the antenna sitting on my passenger seat before it dropped out. This is with a substantial amount of trees and power lines in the way. If I was needing to, I could mount the main panel further up the 25 meter high tower and perhaps even get a telescopic pole at the other end to get line of sight between the two units.
I’m hoping to test this with Axia Livewire audio running over it (as multicast data) at some point in the near future. Having a full 8×8 node available at an OB could be incredibly useful.
Get the Broadcast Technology Newsletter
Sign up for the email newsletter about media and technology. Sent irregularly. No spam.