 Hey YouTube, it's Tosses with RF Elements, and today's episode of Inside Wireless, we're going to talk about MCS rates. MCS stands for Modulation and Coding Scheme. MCS rates are one of the parameters of RF radios for WISP networks, and it tells you how much throughput we can achieve. Let's have a look at how MCS rates work. Radio manufacturers often list their highest achievable throughputs, output power, receipts sensitivities, and MCS rates in their spec sheets. Besides modulation techniques, the MCS rate includes information about the number of spatial streams and coding rate. The modulation technique determines the type of modulation used to encode the data. With QUAM modulation, the number tells us the amount of states the carrier signal can have. The higher the modulation number, the more information we're able to pack into the same bandwidth at the expense of higher required SNRs. If you want to know more about QUAM modulation, check out our previous video by clicking on the link in the corner or in the video description. The fractional number next to the modulation type tells us the part of the data throughput that's useful data. For three-fourths, three out of the four bits are useful data, and the fourth is error protection-related data. Channel size is given in megahertz and tells us the width of the spectrum the signal takes, the larger the channel size, the higher the throughput. The number of spatial streams tells us how many physical separated channels we use for data transfer. Naturally, the maximum throughput increases with every additional channel, but it's also hardware-intensive. For every new channel, takes another antenna and radio. Starting with 802.11a in newer standards, the guarding interval is a short period of time inserted after each symbol, during which a part of the data is repeated to improve the error immunity. The longer the guard interval, the better the error immunity is. It's important to understand that the MCS rates you work with depend on other radio settings such as output power or SNR requirements of the received signal. If you want to know more about this topic, check out our previous video by clicking on the link in the corner or in the video description. In reality, the throughput your link is able to deliver can only approach the theoretical maximum you find in a datasheet. The multi-path propagation of RF signal causes smaller or larger losses to the signal power influencing the received signal strength and eventually the real throughput you can work with. If you find our videos useful, like, leave a comment, or consider subscribing to our channel for more interesting videos.