4 ms·

At first, I wouldn't have thought that they would use encoding to maximize efficiency. But now that I think about it, their goal isn't efficiency but rather con

by pothibo 14y ago

At first, I wouldn't have thought that they would use encoding to maximize efficiency. But now that I think about it, their goal isn't efficiency but rather consistency. So yeah I was wrong. Maybe I thought this was more primitive than what it really is :/

nitrogen 14y ago
You seem to be trying to say something, but it's not coming across. What is primitive? How is it primitive? How do you describe the difference between efficiency and consistency in your usage? Is English not your primary language? My exposure to this stuff is limited to a few exercises in a Matlab class years ago, plus what I read on HN and Wikipedia. Based on what I understand, from a data transmission perspective, there is no difference between efficiency and consistency. There is a theoretical maximum amount of data that can be transmitted using a given medium, bandwidth, and error rate. The only goal is to get as close to that maximum as possible. Also, there's no shame in admitting you're wrong. In fact, every opportunity to be wrong is an opportunity to learn.
- pothibo 14y ago
  Yeah, english isn't my primary language and I haven't spoken it in a long time so sorry if I can't make my point across :) I'm not ashamed for being wrong. If that'd be the case I would have been ashamed my whole life heh. When I said consistency I was referring to low-error rate in the signal. I should have said that but couldn't find the correct word for it. Efficiency meant efficiency in the bandwidth usage. So in that sense, there's always a tradeoff between efficiency (use 100% of the bandwidth to transmit real data) and consistency (make sure that 100% of the sent data is error-free) Now, when I first wrote my comment. I had the feeling that communication was very basic commands. like a 2 bit integer for movement direction (00 up, 01 down, 10 left, 11right). So if you'd use such a scheme to communicate instruction to the rover, there would be an obvious overhead (encoding 2 bit into 4, 10, etc). But now that I really think about it, instruction sent to the rover are probably very complex, which increase entropy, which in the end, made my first assumption wrong, is this clear? I hope it is ;) If not, I can rephrase !
  - vladd 14y ago
    In low-bandwidth environments, the pipeline is like this: 1) plain data initial stream. 2) compress it. 3) encrypt it or/and sign it. 4) add error-checking or even error-correction information. The reason you do encryption (3) after compression (2) is because you don't want encryption to affect the compression rate of the initial stream. If you were to do it in the reverse order (first encryption and then compression) then yes, the resulting message could be bigger.

by pothibo 14y ago

nitrogen 14y ago

You seem to be trying to say something, but it's not coming across. What is primitive? How is it primitive? How do you describe the difference between efficiency and consistency in your usage? Is English not your primary language? My exposure to this stuff is limited to a few exercises in a Matlab class years ago, plus what I read on HN and Wikipedia. Based on what I understand, from a data transmission perspective, there is no difference between efficiency and consistency. There is a theoretical maximum amount of data that can be transmitted using a given medium, bandwidth, and error rate. The only goal is to get as close to that maximum as possible. Also, there's no shame in admitting you're wrong. In fact, every opportunity to be wrong is an opportunity to learn.

pothibo 14y ago
Yeah, english isn't my primary language and I haven't spoken it in a long time so sorry if I can't make my point across :) I'm not ashamed for being wrong. If that'd be the case I would have been ashamed my whole life heh. When I said consistency I was referring to low-error rate in the signal. I should have said that but couldn't find the correct word for it. Efficiency meant efficiency in the bandwidth usage. So in that sense, there's always a tradeoff between efficiency (use 100% of the bandwidth to transmit real data) and consistency (make sure that 100% of the sent data is error-free) Now, when I first wrote my comment. I had the feeling that communication was very basic commands. like a 2 bit integer for movement direction (00 up, 01 down, 10 left, 11right). So if you'd use such a scheme to communicate instruction to the rover, there would be an obvious overhead (encoding 2 bit into 4, 10, etc). But now that I really think about it, instruction sent to the rover are probably very complex, which increase entropy, which in the end, made my first assumption wrong, is this clear? I hope it is ;) If not, I can rephrase !
- vladd 14y ago
  In low-bandwidth environments, the pipeline is like this: 1) plain data initial stream. 2) compress it. 3) encrypt it or/and sign it. 4) add error-checking or even error-correction information. The reason you do encryption (3) after compression (2) is because you don't want encryption to affect the compression rate of the initial stream. If you were to do it in the reverse order (first encryption and then compression) then yes, the resulting message could be bigger.