What is a transparent bridge, and why can’t we use them in a wireless network to reduce congestion?


Back in the early days of the telephone, customers had what was called a party line. In this setup, the phone company strings  one common phone line into a neighborhood, and when
a phone call was intended for your house, the operator would ring the line with your designated number of rings. You were on the honor system to pick up
and listen only when the ringing was intended for your house. It takes little imagination to understand that only one person could be on the phone at the same time with this shared configuration.

antique phone and generator oak box 1920's 1930'?

Flash forward to 2013, and a modern computer network . Believe it or not the local  (ethernet) network works much the same as a party line.  All computers on the network listen and are only supposed to answer when being talked to. The idea of ethernet bridge came along when somebody figured out you could have a device on the wire that would prevent unwanted Ethernet packets ( analogous to rings) from traversing a segment of the wire they are not intended for. The benefit of the bridging device is to segment of the transmissions on a wire and reduce a good bit of the overhead from data not intended for your  network segment.

Wireless networks, based on 802.11 technology also could benefit from  a transparent bridge. They share the property that all shared devices must listen for their address and only answer when spoken to. Unfortunately there is no good place to insert a bridge device on a wireless network.  There is no wire containment of transmissions.  For the most part, once broadcast, transmissions spread out in all directions ,and thus nothing can stop a wireless transmission from reaching unintended devices. The only thing a network operator can do to relieve congestion is to divide the network up in geographic segments and limit the power at each tower from encroaching on neighboring segments.

Related Article: More ideas on how to improve wireless network quality.

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