Single channel per carrier

<h2 id="advantages">Advantages</h2>
<ul><li>simple and reliable technology</li>
<li>low-cost equipment</li>
<li>any bandwidth (up to a full transponder)
<ul><li>usually 64 <a href="/facts/Kilobit_per_second/Nv9VoT7T">kbit/s</a> to 50 <a href="/facts/Megabit_per_second/Nv9VoT7T">Mbit/s</a></li></ul></li>
<li>easy to add additional receive sites (<a href="/facts/Earth_station_(communications)/pvVfBAwg">earth stations</a>)</li></ul>
<h2 id="disadvantages">Disadvantages</h2>
<ul><li>inefficient use of satellite bandwidth for burst transmissions, typically encountered with packet data transmission</li>
<li>usually requires on-site control</li>
<li>When used in remote locations, the transmitting dish must be protected.</li></ul>
<h2 id="mcpc">MCPC</h2>
<p>SCPC was the successor multiple channels per carrier (MCPC).
</p><p>With MCPC, several subcarriers are combined or multiplexed into a single bitstream before being modulated onto a carrier transmitted from a single location to one or more remote sites.  This uses <a href="/facts/Time-division_multiplexing/tv7bMh1v">time-division multiplexing</a> (TDM) as well as <a href="/facts/Frequency-division_multiplexing/lgj6TMU1">frequency-division multiplexing</a>. It is a <a href="/facts/Retronym/yBLuNepw">retronym</a> of sorts, as it was the only way <a href="/facts/Radio_network/rp6kCehQ">radio networks</a> were transmitted ("<a href="/facts/Piggybacking_(data_transmission)/1gAGN6We">piggybacked</a>" on <a href="/facts/Television_network/xq32nKxz">television networks</a>) until SCPC.
</p><p>In <a href="/facts/Digital_radio/X0Kp5l8E">digital radio</a> and <a href="/facts/Digital_television/KQCyILQa">digital television</a>, an <a href="/facts/DAB_ensemble/YE7hK8cw">ensemble</a> or other multiplex or multichannel stations can be considered MCPC, though the term is generally only applied to satellites.
</p><p>The major disadvantage of MCPC is that all of the signals must be sent to a single place first, then combined for retransmission — a major reason for using SCPC instead.
</p>
<h2 id="frequency-hopping">Frequency hopping</h2>
<p>SCPC became somewhat obsolete after the invention of <a href="/facts/Frequency-hopping_spread_spectrum/hJS6o3xy">frequency hopping</a>.
</p><p>Frequency hopping (<a href="/facts/FHSS_(disambiguation)/lf0gl0II">FHSS</a>) is a system invented by <a href="/facts/Hedy_Lamarr/j6LwkVeh">Hedy Lamarr</a> in which radio signals rapidly change frequency to avoid interception. FHSS required the use of MCPC, as SCPC cannot change frequency mid-broadcast. FHSS was the basis for many technological advancements like <a href="/facts/Wi-Fi/u94quCsx">Wi-Fi</a>, <a href="/facts/Bluetooth/sWAjpMrj">Bluetooth</a>, and <a href="/facts/GPS/DKVLnzF3">GPS</a>, which could not have been achieved with SCPC.
</p>

Single channel per carrier open-in-new

Single channel per carrier