I can't Google for this -- I just tried. Broadcast radio, and DirectLink satellite TV, have Really Expensive transmitters to serve lots and lots of cheap receivers, because it minimizes total system cost. "Old style" satellite TV had (fairly) inexpensive transmitters and (until people put them in their back yards) a few big expensive receivers (and antennas). Because -- it minimizes total system cost (at least until everyone put one in the back yard). Is there a name for this sort of economic decision? I'm trying to write some material for training new engineers, to give them an idea of how decisions like this are made. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com I'm looking for work -- see my website!
Symmetric vs. asymmetric radio service
Started by ●September 13, 2016
Reply by ●September 13, 20162016-09-13
Tim Wescott wrote:> I can't Google for this -- I just tried. > > Broadcast radio, and DirectLink satellite TV, have Really Expensive > transmitters to serve lots and lots of cheap receivers, because it > minimizes total system cost. > > "Old style" satellite TV had (fairly) inexpensive transmitters and (until > people put them in their back yards) a few big expensive receivers (and > antennas). Because -- it minimizes total system cost (at least until > everyone put one in the back yard). > > Is there a name for this sort of economic decision? I'm trying to write > some material for training new engineers, to give them an idea of how > decisions like this are made. >Upfront v. recurring? -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix.
Reply by ●September 13, 20162016-09-13
On Tue, 13 Sep 2016 17:25:56 -0500, Tim Wescott <seemywebsite@myfooter.really> wrote:>I can't Google for this -- I just tried. > >Broadcast radio, and DirectLink satellite TV, have Really Expensive >transmitters to serve lots and lots of cheap receivers, because it >minimizes total system cost. > >"Old style" satellite TV had (fairly) inexpensive transmitters and (until >people put them in their back yards) a few big expensive receivers (and >antennas). Because -- it minimizes total system cost (at least until >everyone put one in the back yard). > >Is there a name for this sort of economic decision? I'm trying to write >some material for training new engineers, to give them an idea of how >decisions like this are made.There is also the "ricochet" network, where nodes pass packets to their destination. -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Reply by ●September 13, 20162016-09-13
>I can't Google for this -- I just tried. > >Broadcast radio, and DirectLink satellite TV, have Really Expensive >transmitters to serve lots and lots of cheap receivers, because it >minimizes total system cost. > >"Old style" satellite TV had (fairly) inexpensive transmitters and (until>people put them in their back yards) a few big expensive receivers (and >antennas). Because -- it minimizes total system cost (at least until >everyone put one in the back yard). > >Is there a name for this sort of economic decision? I'm trying to write>some material for training new engineers, to give them an idea of how >decisions like this are made. > >-- > >Tim Wescott >Wescott Design Services >http://www.wescottdesign.com > >I'm looking for work -- see my website!Perhaps "Pareto optimal" is the term you are looking for. https://en.wikipedia.org/wiki/Pareto_efficiency "Pareto efficiency, or Pareto optimality, is a state of allocation of resources in which it is impossible to make any one individual better off without making at least one individual worse off. The term is named after Vilfredo Pareto (1848–1923), an Italian engineer and economist who used the concept in his studies of economic efficiency and income distribution. The concept has applications in academic fields such as economics, engineering, and the life sciences." Ced --------------------------------------- Posted through http://www.DSPRelated.com
Reply by ●September 13, 20162016-09-13
On Tue, 13 Sep 2016 17:25:56 -0500, Tim Wescott <seemywebsite@myfooter.really> wrote:>I can't Google for this -- I just tried. > >Broadcast radio, and DirectLink satellite TV, have Really Expensive >transmitters to serve lots and lots of cheap receivers, because it >minimizes total system cost. > >"Old style" satellite TV had (fairly) inexpensive transmitters and (until >people put them in their back yards) a few big expensive receivers (and >antennas). Because -- it minimizes total system cost (at least until >everyone put one in the back yard). > >Is there a name for this sort of economic decision? I'm trying to write >some material for training new engineers, to give them an idea of how >decisions like this are made. >I'm not sure I follow your satellite TV example, since the earth station expense for U/L and D/L didn't differ that much with the big sites, i.e., the TX wasn't necessarily cheaper than the RX and was probably more expensive. Cellular systems are comparable, though; e.g., handsets are way cheaper than basestations, by many orders of magnitude. So are cable systems and many similar systems. The term "big stick" gets used sometimes in these contexts to refer to a large, expensive central antenna or tower, such as for a broadcast TV/Radio transmitter. I think the terms you used in the title are appropriate. They do apply to and are often used to describe the channel usage as well; e.g., many systems have much more bandwidth and data capacity in the downstream direction than upstream, especially as experienced by a single user terminal, so the term "asymmetric" is often applied, especially if the user terminal uses a different bandwidth, channel, or waveform than the provider. So, since "asymmetric" is used to describe the channels, physical layers, throughput, etc., I don't know why it wouldn't be appropriate to also apply it to the terminal economics.
Reply by ●September 14, 20162016-09-14
On Tuesday, September 13, 2016 at 3:26:04 PM UTC-7, Tim Wescott wrote:> I can't Google for this -- I just tried.> Broadcast radio, and DirectLink satellite TV, have Really Expensive > transmitters to serve lots and lots of cheap receivers, because it > minimizes total system cost.> "Old style" satellite TV had (fairly) inexpensive transmitters and (until > people put them in their back yards) a few big expensive receivers (and > antennas). Because -- it minimizes total system cost (at least until > everyone put one in the back yard).It is actually more interesting. In the days before backyard TVRO antennas, the FCC required them to be fairly big. Partly that was necessary to make sure that they pick up one satellite within the diffraction width. But the FCC requirement was bigger than it needed to be. Those wanting to build home receivers petitioned the FCC to allow for smaller ones. The power per channel for the big antenna satellites is about five watts. It takes a certain size to get enough signal to get above the thermal noise, but that gets smaller as amplifiers get better. When they are owned by TV networks, the cost is a fairly small fraction of the cost of running a network, and a good signal is pretty important. For home use, cost is much more important (and it isn't really the number that matter) and signal not quite as important.> Is there a name for this sort of economic decision? I'm trying to write > some material for training new engineers, to give them an idea of how > decisions like this are made.As someone noted, Pareto is part of the answer, but it seems to me part of what you are asking is economy of scale. Making a lot of them decreases the cost per item. As quantity went up, they got pretty good at making them cheap enough, if you had enough yard to put one in. Mostly that was for rural homes. The small dish system takes about 100W per channel, (in both cases covering the whole US). That allows for a 20 times smaller dish. (I didn't look up the numbers, but I think they are close.) -- glen
Reply by ●September 14, 20162016-09-14
system terms would be broadcast point to multi-point point to point etc. https://en.wikipedia.org/wiki/Point-to-multipoint_communication m
Reply by ●September 14, 20162016-09-14
On Tuesday, September 13, 2016 at 3:26:04 PM UTC-7, Tim Wescott wrote:> I can't Google for this -- I just tried.The symmetric vs. asymmetric reminds me of a different, and currently interesting, point. When WiFi started, it was assumed symmetric, at least in terms of the power requirements for each side. Now we have many portable devices (such as cell phones) that can't really afford the power to reach some stations, but where those stations can afford the power. I only found recently that the original design for the cellular phone system was for car phones, with a good power source, and then someone figured out that the same system would work with battery powered handsets. But I presume that has been included in newer cell phone systems. The OP was asking about cost, but it also comes up in power considerations.
