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In my Project transmitters constantly transmit some data. I want to receive all the data in single receiver at the same time. I searched about RF transmitter and receiver. But Many to One not possible at the same time in RF. What type of transceivers I can use? I can't use wifi coz in my projects the nodes adds or leaves dynamically and wifi takes a moment to connect.

Is there any type of transceivers can I use? I am new to Electronics and I don't know much about it.

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    \$\begingroup\$ Explain the amount of data that is needed to be sent and how often it has to be sent and how many transmitters might be involved. \$\endgroup\$
    – Andy aka
    Jan 16, 2017 at 14:30
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    \$\begingroup\$ But Many to One not possible at the same time in RF Oh Yes it is, you need something like OFDMA: en.wikipedia.org/wiki/… but that is extremely complex and way beyond what any beginner will be able to use. \$\endgroup\$ Jan 16, 2017 at 14:33
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    \$\begingroup\$ electronics.stackexchange.com/questions/74272/… \$\endgroup\$
    – Andy aka
    Jan 16, 2017 at 14:36
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    \$\begingroup\$ You need to either deal with collisions in communications, use specified times of transmission that don't interfere (time division multiplexing), use different RF bands and a method of simultaneous receiving (Bragg crystal?), or else have a master request transmission one by one in a round-robin fashion. \$\endgroup\$
    – jonk
    Jan 16, 2017 at 14:47

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There are several ways to get many to one reception in RF, and it's usually referred to a X division multiplex.

There's Time Division Multiplex, TDMA. Somehow, each transmitter knows the time (perhaps a clock, perhaps a receiver), and transmits for its individual burst time.

There's Frequency Divison Multiplex, FDMA. Each transmitter is given a relatively narrow channel. The receiver looks at them all wideband, or tunes to one at a time. GSM/PCS uses a combination of these.

There's Code Division Multiplex, CDMA. Each transmitter is given a spreading code. This is how GPS works. At the receiver, the incoming signal is correlated with each code to separate the signals. It does have the so-called Near/Far problem, where two transmitters at different distances from the receiver must power control to be received at a very similar strength. Not a problem with GPS, but was trouble in IS-95.

And then there are all possible combinations of the above.

All of these allow all transmitters access to the medium simultaneously.

Less organised schemes can do Carrier Detect and Collision Avoidance, where each transmitter listens for a quiet time to transmit, and can tell if its transmission got stomped on, and try again.

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