Twenty-first century communications will be dominated by intelligent high-speed information networks. The rapid growth of high-speed networks has led to many technological as well as social developments. As the networks supporting these services shift from the experimental phase to commercial operation, the pricing of limited resources will become an important problem. In this paper, statistical Multiplexer with QOS parameter control is implemented using VLSI design technologies. In communications systems by far the most common form of multiplexing is that of time division multiplexing (TDM). In this technique, the entire capacity of the shared transmission medium is allocated ...view middle of the document...
In the emerging networks, the QoS issue will be much more complicated since the QoS requirements will differ from user to user, so the networks will need to provide heterogeneous QoS. This is an important issue due to the fact that QoS based pricing structures are increasingly being advocated.
One of the challenging problems in networks is to characterize the admissible region of the numbers of connections or flows that can be admitted into the network in order to guarantee a given level of QoS. It is usually specified by packet loss probability constraints or bounds on the delays incurred by the bits as they traverse the network from source to destination.
Performance guarantees in QoS networks are either deterministic or statistical. A deterministic service guarantees that all packets from a flow satisfy the worst-case end-to-end delay bounds and no packets are dropped in the network. A deterministic service provides the highest level of QoS guarantees, however, it leaves a significant portion of unused network resources. A statistical service makes probabilistic service guarantees, for example, of the form: Packet loss probability < Threshold. With this assumption a statistical service can improve upon a deterministic service by (1) taking advantage of knowledge about the statistics of traffic sources, and (2) by taking advantage of the statistical independence of flows .
The proposed model frees network operators from the manual and error-prone bandwidth reservation process which is currently used in practice. Features of this model are, reasonable bandwidth utilization, robustness to traffic uncertainties, simplicity and node architecture independence. This paper presents the technical detail, simulation and analysis for a study of the changing statistical properties of packet traffic.
Computer application generates the data in a bursty manner for transmission. These bursts of information are separated by long idle periods and formatted into packets that contain header which identify the source and destination. The packets are then transmitted over a communication line. If we assigned a dedicated line to each terminal it becomes highly inefficient. In “fig. 1” the first three lines show the times when the packets would have been transmitted if each terminal had its own dedicated line at speed R bps. Last line shows the time when packets are multiplexed. Because the terminal generates the packets in bursty manner, it is possible to combine the packet streams into a single line of speed R bps. Because packet generation time overlap, the multiplexer must buffer and introduce delay in some of the packets. Thus by aggregating the packet flows into a single transmission line, the multiplexer reduces the system cost by reducing the number of lines.
Dedicated and shared lines
In general, packets multiplexer are used in two situations: packets arrive from multiple lines for transmission to a remote site; packets arrive...