| 摘要 |
The possibility of overload (saturation-lockup) condition of an ALPC satellite communication network is avoided by a scheme that grants network entry (allocates TWT power) to each link one at a time. As each link is granted entry into the network, the corresponding TWT probability density function is computed and then integrated to obtain a TWT cumulative distribution function. The required rain margin Mr for a specified availability is determined from the cumulative margin. The computed margin Mr is set equal to the initial satellite TWT operating point change (multiplicative factor) MR1 due to rain fade, MF1=Mr to ensure that network stability considerations and rain fades equally constrain network performance. This result is then used to compute the value of the corresponding multiplicative factor MF2. These two factors, when expressed in decibels, may be added to the nominal (no rain) TWT operating point (also expressed in decibel notation) to predict the maximum TWT operating point value in response to rain stress at the specified system availability. This predicted maximum TWT operating point is then compared to the analytically determined value of the TWT stability point. If the TWT stability point is not exceeded for the current number of links then an additional link may be added, otherwise, the last link requesting entry into the network is denied access. After the maximum permissible number of terminals has been accommodated, the final actual values of TWT stability point, stability margin, and link availability are computed and the allocation process is terminated.
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