Читать книгу Mobile Communications Systems Development - Rajib Taid - Страница 108

It was mentioned in Section 4.1.4 that the GPRS RLC/MAC layer messages are encoded/decoded at bit level using CSN.1 [10] method. Even the presence or absence of a single bit of information in a particular communications signaling message matters a lot for the receiver of the message because it may not be able to decode the rest of the received message successfully. Sometimes, if the complete information to be sent does not fit in a single signaling message, the same may be transferred in a segmented way, and this is indicated by a presence of a bit in the first message segment already sent to the receiver.

Similarly, the segmentation of the New Radio (NR) RRC layer messages i.e. RRCReconfiguration or RRCResume, in DL direction, and UECapabilityInformation, in UL direction, has been introduced as part of the 5G system Release 16. This is due to the limitation of the maximum PDU size of 1900 bytes as supported by the NR PDCP layer. The 5G NR air interface control plane protocol layer shall be described later in Chapter 18