Best Wireless Practices
Making several small adjustments can make a huge difference in wireless performace.
Follow these guides as close as possible to ensure a smoothly operating set.
Something to be aware of:
The bigger the film set, the bigger the issues
Large film sets have lots of large departs spread across long distances. More departments are going wireless. And as they do, the license free 2.4GHz band is getting more and more crowded. They also have a lot of human bodies, and bodies absorb wireless signals.
If you are on a large film set, you should recognize you face the largest wireless challenge. Read this guide closely to ensure you're prepared.
Something to do:
Keep All Antennas Vertical
Antennas emit/receive their signal in the shape of a donut. Primarily out the sides of the antenna.
If you place an antenna on a side and then pan camera, you may actually pan your receiver into a dead zone and dramatically reduce reception.
Something to do:
Video Village: Signal Dead-zone
If you operate from video village, you likely have positioned yourself (and the Alpha Link Transmitter) in one of the worst spots. Large monitors and human bodies are two of the most common signal blockers. Add to that: wireless video receivers, sound hops, a nearby AC on a FIZ, and a couple of producers on WiFI.
But you don't need to leave. Elevating the transmitting antenna, as simple as it sounds, can often reduce interference dramatically. For this exact situation, our high-gain antenna kit comes with a movable antenna base and a 6' extension cable. By elevating the antenna above head/monitor height, you can free up the signal.
Also, remember, if elevating multiple antennas in video village—such as a video receiver—try to position them at different heights. For example, put the videos receivers at 7ft, the Alpha Link at 8ft, and the com system at 9ft.
Something be aware of:
THINK ABOUT WIRELESS AT THE START OF THE DAY
Out of sight doesn't mean out of mind. Be aware of how wireless signals work, and hold them in your mind as you start your work day, build your camera, and place monitors. Doing so can mean you avoid the issues in the first place.
It may be tempting to position the operator at a convenient place farther away from the set or behind a wall so you don't have to move all day. But a single ruined take will likely cause more trouble than moving an operator's position between takes.
Something to do:
Separate Antennas from different Systems
Avoid placing antennas, even of different frequencies, next to each other. A wireless video transmitter, even though it runs on 5.8GHz, will overwhelm an Alpha Link Receiver running on 2.4GHz if placed close enough.
Try to place them above and below each other. Imagine their signals like a stack of donuts on top of each other. You are placing the antenna of one system in the weakest part of the field of a different system.
Something to do:
before you roll, Watch the Orange lighT
Many times with wireless signal loss, you can actually see it coming before it ruins a shot. The Alpha Link RX has an orange light on the receiver. If you see it switch from a solid orange light to rapidly blinking, it means it is on the edge of signal loss.
When moving the camera between setups, watch for that blinking light. If you see if blink, even for a split second, it can mean the receiver is right on the edge of signal loss, and now is the time to take action to prevent it from ruining a shot.
Teach anyone around the camera, AC's, even the dolly grip, what that means.
Something to be aware of:
The Alpha Link is Frequency Hopping
This is relatively new technology. Every couple of milliseconds the Alpha Link TX and RX will together jump from one frequency, like 2.456 GHz, to another, like 2.489 GHz. This is very helpful when trying to avoid signal interference as it will generally just skip over bad channels.
But it does mean that if the entire 2.4 GHz spectrum on your film set has something on it (WiFi, Bluetooth, Preston MDR, Alexa Mini WiFi, Alexa WCU-4, Sound Hops), there may be no open frequencies for it to jump to. Think of it like trying to get across a river by jumping on rocks. If one or two of the rocks is flooded, you may get a little wet, but still get across. If the entire river is flooded, you may not make it.
Also, when we say channel (as in the chn,12; command), we really mean, frequency hopping pattern. So when trying to change the "channel" of your Alpha Link, be aware, it's likely not going to help you reduce interference. Your time would be better spent looking at the other practices.
Something to be aware of:
Radio Towers and Solar Events
One customer that was struggling with wireless eventually discovered that their particular shooting location, at high elevation in Canada, was known for experiencing stray radiation from solar activity.
Another time, a customer found out they were near a high power radio tower.
Sometimes, you just can't control the wireless environment.