Free GSM Protocol Stack Introduction

GSM Protocol Stack explained

Protocol Stack

GSM Layer 1 Radio Transmission

GSM900

Upstream : 890 ~915 Mhz

Downstream : 935 ~ 960 Mhz

Duplex Interval : 45 Mhz

Bandwidth : 25 Mhz

Frequency Interval : 200 Khz

TDM / FDMA

Modulation – GMSK

GSM Layer 2 – Data Link Layer DLL

LAPDm Link Access Procedure

GSM Layer 3 Messaging Layer

RR Radio Resource Management

• Channel Allocation
• Handover
• Timing Advance
• Power Control
• Frequency Hopping

MM Mobility Management

• Location Management
• Security

CM Connection Management

• Call Control CC
• Supplementary Services
• Short Message Service

Call Control CC Sub Layer

• Call Routing
• Call Establishment
• Maintenance
• Release

https://www.poplabtelecom.com/gsm-channels/

GSM Components Explained

GEO-Mobile Radio Interface Specifications (Release 3)