A simple Excel-based simulation tool described in earlier papers was developed to simulate the operation and performance of distributed network systems having time-varying data traffic patterns. Such networks use protocols to increase or decrease resources allocated. These resource-allocation protocols can have settable parameters such as numerical thresholds. Improper choices of these parameters can cause undesirable results such as allocations oscillating between higher and lower values. This paper describes modifications to the simulator to analyze the degree to which oscillations occur, to generate and store multiple sets of message-generation data allowing faster simulations, and to present additional message-delivery performance results. Also, the user interface for the simulator has been expanded to clearly show all simulation results and to show them side by side for two protocols that are being compared. The new simulator features and new user interface are presented.

Data-buffering techniques currently used in time-division-multiple-access (TDMA) networks are described, including a short-delay technique called sub-framing. The sub-framing technique produces minimum user-to-user streamed-data throughput delays but results in data-transfer interruptions when TDMA time-slot resources have reassigned positions in the time frame. A simple modification to the sub-framing data-buffering technique is proposed, and it accommodates dynamic TDMA time-slot resource reassignments without data-transfer interruptions. This proposed data buffering technique provides the same minimum user-to-user streamed-data throughput delay, which is approximately equal to the difference between the TDMA frame time and the TDMA time-slot duration, but does not have data-transfer interruptions when TDMA time-slot resources have reassigned positions in the time frame.

An important application of spread-spectrum (SS) in military communication systems is that of making the signal difficult to intercept by unauthorized receivers. Error-correction coding techniques may be employed to reduce the required input signal-to-noise ratio at the receiver, allowing the system to operate at a lower power level, hence resulting in a lower probability of interception. In the absence of error-correction coding, a specified message bit rate, transmitted signal bandwidth, and required bit-error probability at the receiver will yield a required signal-to-noise ratio for each type of spread-spectrum system. When coding is employed, a specified decoder delay time implies a specified code complexity, and can be used to determine bounds on the required receiver signal-to-noise ratio. These performance bounds are evaluated as functions of the specified parameters. In addition, one may specify a burst interference environment in that the system must operate. Presented is the evaluation of the increase in the upper bound on signal-to-noise ratio as a result of the specification of a correctable single-burst time. This increase indicates an antiintercept /antijam tradeoff.