Why is it so hard to create reliable long-range video/audio transmission? In today day and age, I think every piece of software in my smartphone or computer require more or less constant uninterrupted access to the Internet and it works almost flawlessly. But whenever I call my parents that are 500 kilometers away from me in a messenger app, we almost always have some interruptions, connection drops, etc. After certain recent events, I find a lot of my favorite bloggers move away to live in the different parts of the world, and when they try to have some joint episodes on Youtube, it happens almost always that somebody’s connection would drop for a minute or so. Why is it so easy to download stuff from American servers at 100 Mb/s being in Eastern Europe, but almost impossible to have uninterrupted video/audio connection over the same distance?
In: 0
The key word is “uninterrupted”.
The constant access that your cell phone and smart devices have isn’t actually uninterrupted… it’s “always on” but interruptions are commonplace even if you never notice.
Same goes for downloads. Does the download come through at full-throttle for the entire download, or does the progress bar speed up and slow down sometimes mid-download? More often than not, it does have those speed-ups/slow-downs! Those are interruptions! You just don’t notice them!
The issue with **live** audio/video transmission is that all the delays/interuptions become noticeable, not that delays/interruptions are suddenly created.
Realtime video requires a low processing delay to enable people to communicate in real time back and forth without accidentally talking over each other.
Most file downloads can be buffered and retransmitted in case of an error. This is even true for radio streaming, which can have a delay in the order of 15 to 30 seconds compared to an over-the-air transmission. This would not work in a conversation. You can observe the problem with a delay of a few seconds on television during reports from a remote location like a war zone. The person in the studio wants to interrupt the other speaker, but he keeps talking, and then they both may go into a deadlock of waiting on each other. Being professionals, they can recognize this situation and get out of it.
If you transmit from a mobile device, the connection to its wired base station is prone to interference from other users. When you download software, you only experience the speed fluctuating because the Transmission Control Protocol takes care of any errors by asking the other party to resend. It doesn’t matter if the download is a minute “old” because it is updated not that often or at all.
The video quality is usually poor even when reliably working because it costs money for the platform to handle thousands or hundreds of thousands of users, and they select the lowest bitrate that people will tolerate.
Latest Answers