求助各位英语好的高手～ rescued, 高手, 文章

If reassignments are employed and new calls that would be blocked are rescued and accepted in the system, an average increase of 20% in system throughput is achieved and code tree utilization is determined by the offered traffic load only.

这个句子中：rescued 怎么解释？在文章中还有rescued call、rescued code出现，我实在不明白这个rescued 是什么意思
谢谢各位高手的解答

文章题目是：减小WCDMA下行链路中由DCH重配置引起的呼叫建立时延
主要说的是用改变编码的方式来减少这个rescued call的建立时延