3 ) Token Passing Ring - a non-contention protocol

Station Latency in bits ...

Ring Latency ...

Delay of packet is ...

4 ) Aloha - a very basic contention protocol

Delay of packet is ...

Note how the protocol saturates and is unusable due to collissions above a traffic intensity of 0.18

5 ) Carrier Sense Multiple Access/Collision Detect - CSMA/CD - a popular contention protocol

Laplace transform of frame

length distribution ....

Delay of packet is ...

6) Simple M/D/1 Queue - used as a performance bound

Bounded minimum time in the queue .....

Queue .

Here we compare all four protocols. Compare .....

Comparison shows the superior performance of CSMA and Token Ring.

Comparative Performance Analysis

- An examination of the performance of some common multi-access protocols

1) Set up some Common Parrameters ...

Frame length bits .....

Number of users (channels) ....

Channel Rate bits/sec ....

Speed of light C....

Permitivity of free space ...

Relative Permitivity of cable ...

Velocity around channel ...

Channel Length .....

Channel Propagation Delay tau ...

2 ) Frequency Division Multiple Access - FDMA - a non-contention protocol

Delay of packet is ....

2 ) Time Division Multiple Access - TDMA - a non-contention protocol

Delay of packet is ....