gsm協(xié)議棧原理ppt課件(已修改)
2025-05-17 12:35 本頁面
【正文】 GSM/GPRS Protocol Stack Architecture Vito Tai Outline ? GSM/GPRS Protocol Stack Architecture ? Introduce the architecture and all modules of Protocol stack ? Common Procedures ? Includes general procedures, like LU, MO call, GPRS ATTACH, and etc., for illustration of the functionality and interaction of modules of Protocol stack. Outline ? GSM/GPRS Protocol Stack Architecture ? Introduction ? L4 ? NAS ? AS ? Data ? SIM ? Common Procedures Introduction: Task . Module ? One Module implements one layer or groups of functionalities. ? Task is the unit of OS scheduling ? The munication between Modules is by Primitives(Messages) ? More overhead in intertask munication ? Put modules into one task ? Share mon memory ? Lousy munications ? Share the same priority ? Other consideration ? General priority arrangement: lower layer higher priority Task1 KAL Module1 Task2 Module3 Module2 SAP MCD TST SAP Introduction: Task main while (1) { receive_msg_ext_q (task_ext_qid, amp。current_ilm)。 process_ilm(amp。current_ilm)。 /*process external ILM */ while (receive_msg_int_q(task_entry_ptrtask_indx, amp。current_ilm)) { process_ilm(amp。current_ilm)。 /*process internal ILM */ } } void process_ilm (ilm_struct *current_ilm) { switch (current_ilmdest_mod_id) { case MOD_CSM: csm_main( current_ilm )。 break。 //…… while (1) { receive_msg_ext_q(task_ext_qid, amp。current_ilm)。 /*process external ILM */ mm_main(amp。current_ilm)。 free_ilm(amp。current_ilm)。 } Multimodule Singlemodule FMIATCIL 4CCSM SMS ALRAC TCMMM/GMMSMSCCSSL2RRLPTDTD a taSMSND CPL4LLCRRRRMMPA LL1NVRAMD riversPPPUARTSIMRMPCL AP D MRL CMACSMUPHBUEML 4ARMIKA L O S a d a p t a t ionREASMSAP headers: define message ids Driver interface ASN file of CC Header file of CC Source file of CC Mcd_parser Generated header file Headers of mon local structure Headers of structures for primitives Headers of mon used enums ASNs of mon used and SS ACT Files Introduction: Directory Structure Layer 4 ? The interface between PS and MMI/AT L4 L4C (1/9) ? L4C ? Layer 4 controller ? Coordinate all L4 modules to perform the requests from AT or MMI ? Interfaces ? There are interfaces between all modules in L4 ? PPP_L4C_SAP PPP ? L4C_ABM_SAP ABM ? Source ? mcu/ps/l4/l4c L4 L4A amp。
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