明白。 顺便问个问题,3gpp中44060,IE的记法好像是ASR1,对于非等长编码比较常用。但是读起来有点费劲,老师解释一下这种记法如何jie? 比如CONTROL ACK: Table 11.2.2.1: PACKET CONTROL ACKNOWLEDGEMENT < Packet Control Acknowledgement message content > ::= -- RLC/MAC control block format < TLLI/G-RNTI : bit (32) > < CTRL_ACK : bit (2) > { null | 0 bit** = < no string > -- Receiver backward compatible with earlier version of the protocol | 1 { 0 | 1 < TN_RRBP : bit (3) > } { 0 | 1 < G-RNTI extension : bit (4) > } { null | 0 bit** = < no string > -- Receiver backward compatible with earlier version of the protocol { 0 | 1 < CTRL_ACK_EXTENSION : bit (9) > } < padding bits > } } ; < Packet Control Acknowledgement 11 bit message > ::= -- 11-bit access burst format < MESSAGE_TYPE : bit (9) == 1111 1100 1 > | { < MESSAGE_TYPE : bit (6) == 110111 > < TN_RRBP : bit (3) > } < CTRL_ACK : bit (2) > ; < Packet Control Acknowledgement 8 bit message > ::= -- 8-bit access burst format < MESSAGE_TYPE : bit (6) == 0111 11 > | { < MESSAGE_TYPE : bit (3) == 000> < TN_RRBP : bit (3) > } < CTRL_ACK : bit (2) > ; Table 11.2.2.2: PACKET CONTROL ACKNOWLEDGEMENT |