RFRing Network vs. Bus Network: Key Differences
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There are many ways stations (i.e., nodes) can be interconnected to form a network. However, some configurations are more popular and frequently used than others. These are known as network topologies, with star, ring, and bus being among the most common.
This article explains the basics of ring and bus networks and highlights the key differences between them.
Ring Network
Figure 1: Ring Network
Figure 1 illustrates a typical ring network configuration. Unlike some networks, there’s no central controller station. Instead, each station performs some control functionalities. All stations are connected end-to-end, forming a continuous loop. This means each station connects to two other stations: one on its left and one on its right. Stations in the ring network can both send and receive data.
Each node in the ring network can recognize its assigned address and retransmit the received signal. When a node wants to send a message, it starts with the destination node’s address, followed by the actual message.
Here’s how message transmission works in a ring network:
- The originating node sends the message to the next node in the ring.
- Communication in the ring is unidirectional. If the receiving node determines that the message isn’t for it (by checking the address), it simply forwards the message to the next node.
- When a node identifies its own address as the destination address, it receives/decodes the message, completing the communication.
Example: Token Ring (from IBM)
Bus Network
Figure 2: Bus Network
In a bus network, all stations share a common cable, referred to as the “bus.” Communication is bidirectional, meaning any station can communicate with any other station.
Here’s how message transmission works in a bus network:
- The sending station broadcasts the message onto the bus.
- All stations receive this message.
- The station for which the message is intended decodes the message.
- This completes the communication.
Difference between Ring Network and Bus Network
Here’s a comparison of the differences between ring and bus networks:
| Feature | Ring Network | Bus Network |
|---|---|---|
| Reliability | Failure of one node can disable the entire system. | More reliable, as the “highway” (bus) is passive. Failure of one or more nodes doesn’t interrupt service for other nodes. |
| Adding Nodes | Requires bringing the network offline to add extra nodes. | Extra nodes can be added without disrupting network operations. |
| Cable Type | Uses specific types depending on implementation (e.g., twisted pair, fiber optic with unidirectional couplers). | Uses coaxial cable or twisted pair due to the need to transmit in both directions. Bidirectional optical couplers are used to tap in optical fiber bus network. |
| Signal Issues | Less susceptible to signal reflections. | Susceptible to signal reflections at impedance irregularities. Impedance mismatches at nodes and ends need to be carefully avoided. |
| Fault Isolation | Fault isolation is easy and straightforward. | Isolation of faults is difficult. |
| Speed of Access | Provides slower speed of access since nodes are accessed sequentially. | Provides faster speed due to direct access. |
| Cost | Generally lower cost compared to other topologies. | - |
| Communication Method | Data passes through each node until it reaches the destination. | Any two stations communicate directly without interference or assistance from other stations/nodes. |
