上行扰码主要用来区分用户，但分为长扰码和短扰码，这两个都是2的24次方个，那么有什么区别，数量一样多干嘛还叫长和短?用户如何知道使用哪个?是系统广播来通知吗?

• Answer: You just can say same number of SC but different decoding length. SC is allocated by RNC which also notify Node B, thus, Node B know this.