From the course: AI in RAN (Radio Access Network): Transforming Mobile Networks

Legacy radio access networks (RAN): A primer

From the course: AI in RAN (Radio Access Network): Transforming Mobile Networks

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Legacy radio access networks (RAN): A primer

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Building on our previous discussion about telecom networks, three components, we are now focusing on the first component, which is the radio access network. Let's consider one cell site where we have taken an example here of a wooden pool, where the antennas are mounted on the top of the wooden pool, where we have the antennas, which is serving two crucial functions, which is communicating with the user devices within their coverage area. And it is connecting via the black feeder cables to the cabinet below. Now, the cabinet here is having certain components inside it. On the right side, if you see, it has certain important components. One is the baseband unit. So baseband unit is acting as a brain, which is performing heavy processing at layer 2 and layer 3. And there are multiple radio units, which is handling different frequency bands and technologies. This equipment transforms the radio waves into digital signals and vice versa. There's a connectivity framework where we have the jumper cables which is basically connecting the radio modules to the antenna, and we have a SIPRI cables, which is a common public radio interface, which connects the radio modules to the baseband unit. These physical connections enable the network's connectivity overall. The SIPRI here, which is in case of the legacy 4G network, this interface facilitates essential functions like inverse Fourier transform processing or advanced signal modulation or channel coding and interleaving. Think of SIPRI as the network's nervous systems carrying vital signals between the different components. As we transition to 5G, this interface is becoming more open and flexible. A transformation we'll explore in depth later on about the enhanced SIPRI. This evolution will define how networks are built and operated. If you see, the overall communication has happened from the wireless connection to the antennas. Then we have the feeder cables which goes to the radio unit. We have a SIPRI to the baseband processing. We have an Ethernet cables which is connected to the transport network, and then we have microwave or fiber connectivity which takes all the information from the radio access network back to the core network. So next time you make a call or load a web page, remember this incredible system working tirelessly to connect your device.

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