A tree network acts to combine at least two star networks together as a single interconnected system of computers. The interconnection of star networks occurs via a bus, which is a main cable that links together the central computers of each of the star networks. This places each workstation computer on each star network in indirect communication with one another, resulting in a network that, on paper, resembles a trunk with branches growing out on all sides, hence the appropriate name of "tree network."
The star networks that comprise the different nodes of the tree network are all autonomous local area networks (LANs) that are fully capable of standing on their own. The tree network topography begins when each central computer of each star network is brought together on the same system via either physical cabling, such as optical fiber or traditional wire cables, or an overarching wireless network that envelops the entire area where the star networks are located. The ideal time and place to utilize a tree network configuration is where the computer workstations are located in tight-knit groups, such as on a college campus where computers are clustered together in different university buildings. Linking the computers together in star networks and then combining the star networks into a larger tree network affords flexibility in network design, allowing entire clusters of computers to be added or removed from the tree network without excessive hassle by simply connecting or disconnecting the central computer of the star network to the bus.
This flexibility, however, is one of the biggest weaknesses of tree networks. The computers on the different star networks are only loosely and indirectly connected via one central computer in each star network, so any network problems involving that computer or that computer's connection to the bus of the tree network will result in the entire star cluster being dropped from the network. This can result in large-scale network outages fairly easily, making a tree network a fragile thing in the event of common network problems such as degradation in signal strength for wireless tree networks or physical damage to the cabling for wired tree networks. The computers on that "branch" of the tree network will still be able to communicate with each other for the time being, but they will be isolated from the rest of the network until the connection to the central bus is restored.