Which layer of network stack do access points operate? (My question also leads me to wonder https://superuser.com/questions/902820/which-device-can-create-a-new-network).
My question arises when reading Tanebaum's Computer Network:
So far in this book, we have looked at a variety of ways to get frames
and packets from one computer to another. We have mentioned repeaters,
hubs, bridges, switches, routers, and gateways. All of these devices
are in common use, but they all differ in subtle and not-so-subtle
ways. Since there are so many of them, it is probably worth taking a
look at them together to see what the similarities and differences
The key to understanding these devices is to realize that they
operate in different layers, as illustrated in Fig. 4-45(a). The
layer matters because different devices use different pieces of
information to decide how to switch. In a typical
scenario, the user generates some data to be sent to a remote machine. Those data
are passed to the transport layer, which then adds a header (for example, a TCP
header) and passes the resulting unit down to the network layer. The network
layer adds its own header to form a network layer packet (e.g., an IP packet). In
Fig. 4-45(b), we see the IP packet shaded in gray. Then the packet goes to the
data link layer, which adds its own header and checksum (CRC) and gives the re-
sulting frame to the physical layer for transmission, for example, over a LAN.
About access points:
802.11 networks are made up of clients, such as laptops and mobile phones, and infrastructure called APs (access points) that is
installed in buildings. Access points are sometimes called base
stations. The access points connect to the wired network, and all
communication between clients goes through an access point.
In computer networking, a wireless Access Point (AP) is a device that allows wireless devices to connect to a wired network using Wi-Fi, or related standards. The AP usually connects to a router (via a wired network) as a standalone device, but it can also be an integral component of the router itself.
Another source says
In a sense, it's very much like a hub in that it pays no attention to the data that crosses it – it simply sends everything that it receives on a wired connection to the wireless transmitter and everything that it receives wirelessly is sent to the wired connection.