As more and more stations are added to an Ethernet, the traffic will go up. Eventually, the LAN will saturate. One way out is to go to a higher speed, say, from 10 Mbps to 100 Mbps. But with the growth of multimedia, even a 100-Mbps or 1-Gbps Ethernet can become saturated. Fortunately, there is [...]
With 10Base5, a transceiver cable or drop cable connects the transceiver to an interface board in the computer. The transceiver cable may be up to 50 meters long and contains five individually shielded twisted pairs. Two of the pairs are for data in and data out, respectively. Two more are for control signals in and [...]
We have now finished our general discussion of channel allocation protocols in the abstract, so it is time to see how these principles apply to real systems, in particular, LANs.IEEE has standardized a number of local area networks and metropolitan area networks under the name of IEEE 802. A few have survived but many have [...]
As the number of mobile computing and communication devices grows, so does the demand to connect them to the outside world. Even the very first mobile telephones had the ability to connect to other telephones. The first portable computers did not have this capability, but soon afterward, modems became commonplace on notebook computers. To go [...]
A different approach to channel allocation is to divide the channel into subchannels using FDM, TDM, or both, and dynamically allocate them as needed. Schemes like this are commonly used on fiber optic LANs to permit different conversations to use different wavelengths (i.e., frequencies) at the same time. In this section we will examine one [...]
One particularly simple way of performing the necessary assignment is to use the algorithm devised by the U.S. Army for testing soldiers for syphilis during World War II (Dorfman, 1943). In short, the Army took a blood sample from N soldiers. A portion of each sample was poured into a single test tube. This mixed [...]
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