【正文】 State chartLAP module has a state machine, it has two instances, sapi0 and sapi3. LAP state machine has 8 states as follows：1. LAP_IDLE：LAPDm is in idle state, no connection established.2. LAP_ESTAB_SABM_SENT：A establish SABM has been sent, the LAPDm is waiting for the answer.3. LAP_MFE：The LAPDm is in multiframe operation.4. LAP_SUSPENDED：The LAPDm is suspended. For sapi0 instance only.5. LAP_RESUME_SABM_SENT：A resume SABM has been sent, the LAPDm is waiting for the answer. For sapi0 instance only.6. LAP_RECONNECT_SABM_SENT：A reconnect SABM has been sent, the LAPDm is waiting for the answer. For sapi0 instance only.7. LAP_TIMER_RECOVERY：The LAPDm is in timer recovery, waiting for ACK for I frame.8. LAP_RELEASE_DISC_SENT：A release DISC has been sent, the LAPDm is waiting for the answer. For sapi0 instance only.9. LAP_GENE: LAPDm Generic state which can handle received message LAP_UNIT_DATA_REQ, LAP_RX_UI_FRAME, LAP_LOCAL_RELEASE_REQ, L1_TX_IND. State chart for lap sapi0 State chart for lap sapi38 L1CAGCH Access Grant ChannelBCCH Broadcast Control ChannelBTS Base Transceiver StationFACCH Fast Associated DCCHLAP Link Access Procedures NCH Notification ChannelPAGCH Packet Access Grant ChannelPCH Paging ChannelPDTCH Packet Data Traffic ChannelsPNCH Packet Notification ChannelPPCH Packet Paging ChannelPRACH Packet Random Access ChannelRACH Random Access ChannelRR Radio Resource SACCH Slow Associated DCCHSAPI Service Access Point IdentifierSDCCH Standalone DCCHTA Timing AdvanceTCH/F full rate traffic channelTCH/AFS adaptive full rate traffic channel for speechTCH/EFS enhanced full rate traffic channel for speechTCH/FS full rate traffic channel for speechTCH/H half rate traffic channelTCH/AHS adaptive half rate traffic channel for speechTCH/HS half rate traffic channel for speechTCH/ full rate traffic channel for TCH/ full rate traffic channel for TCH/ half rate traffic channel for TCH/ half rate traffic channel for =TCH/ full rate traffic channel for =TCH/ full rate traffic channel for SummaryAmong the layers of protocol, the L1C layer lies below the LAP and RR sublayers. It is used to transmit the block required by uplayers and receive block from the network. The L1C relationship diagram is below.Figure 1 L1C relationship diagram Object Model Diagram Objects DescriptionL1C functionalities are divided into two parts, the schedule management and cell management. The schedule management function is to receive and transmit the burst, and the cell management function is to measure the power and the quality.L1C functionalities is mainly described in following：(1) Receive the FCCH and SCH data.(2) Receive the BCCH data.(3) Receive the PCH data according to paging mode.(4) Receive the PBCCH data.(5) Receive the PPCH data according to paging mode.(6) Transmit the RACH data if using GSM service.(7) Transmit the PRACH data if using GPRS service.(8) Receive and transmit the SDCCH data at dedicated mode.(9) Receive and transmit the TCH data at dedicated mode.(10) Support TCHF, TCHH, SDCCH4 and SDCCH8 channel in dedicated mode.(11) Support SIG_ONLY, SPEECH_V1, SPEECH_V2, SPEECH_V3 speech service and TCH/, TCH/, TCH/ data service.(12) Receive and transmit the PDCH data in dedicated mode.(13) Transmit the PDTCH data in idle mode.(14) Transmit the RRBP or single block.(15) Transmit a PTCCH/U burst and receive a PTCCH/D burst in dedicated mode.(16) Receive and transmit the CBCH data.(17) Support DRX and DTX in dedicated mode.(18) Establish or release the TBF.(19) Search all RF channels in the system in 5 seconds.(20) Measure the BA carriers when receiving the PCH to minimize the interruptions in idle mode.(21) Measure the BA carriers when receiving the TCH or SDCCH in dedicated mode.(22) Measure the TCH qu