Gsm And Umts Protocols And CallflowPresentation Transcript
GSM,GPRS,UMTS,HSDPA andHSUPA Protocols and Call flow By Kiran Koona
Overview1. GSM Protocols and Call flow2. GPRS Protocols and Call flow3. UMTS Protocols and Call flow4. HSDPA and HSUPA Protocols.
Layer 1 Protocol 3-Layer ModelTDMA – Time Division Multiple AccessG.703 – ITU PCM frame structureMTP – Message Transfer PartLayer 2 ProtocolsLAPDm Link Access Protocol D-channel-mobileLAPD Link Access Protocol D-ChannelLayer 3 ProtocolsRR – Radio Resource ManagementMM – Mobility ManagementCM – Connection managementBTSM – Base Transceiver Station ManagementSCCP – Signalling Connection Control PartBSSMAP – Base Station SubsystemMAP-Mobile Application PartDTAP – Direct Transfer Application Part TUP , ISUP
Physical Layer1. Txn of bits2. Error detection and Correction3. Interleaving4. Burst Formating5. Measurements6. Power Control7. Modulation and DemodulationBTS-BSC: 64KbpsBSC-MSC:2Mbps (32*64Kbps)
Layer-3: RRMProtocols: RR, RSM, BSSAP.• Cell selection and Reselection Control• Handover procedure• Establishing , maintaining, monitoring and releasing the channels• Monitoring and forwarding of radio connections• Introduction of encryption• Change in transmission mode ,Channel coding depending on channel conditions Advise L1 and L2• MS level measurement commands control• Frequency redefinition Downlink Freq hopping• Broadcasting System Information Downlink• Paging
Layer-3:MMProtocols : DTAP,MAP.• Authentication request/response• Ciphering Information/Commands from MSC• Abort from MSC Auth Failure• Normal location Updating request/response• Periodic location update• TMSI Reallocation Procedure• IMSI attach/detach• IMEI request/response
Layer-3:CM1. Call control (CC) - manages call connections,2. Supplementary service support (SS) - handles special services3. Short message service support (SMS) - transfers brief texts.CC:Mobile-originating call establishment Setup messageMobile-terminating call establishment PagingCall clearing initiated by the networkCall clearing initiated by the MobileDTMFSS:Call ForwardingCall waiting ,Call Hold and ConferenceMulti CallCLIP,CLIR ,COLP and COLRSMS:
SS 7To provide General purpose Signaling system to be used globally.CCS , Out of BandITU-T Q.700 series.Elements: SSP,STP and SCP.Access Links: A to FAnalogy: MTP3 IP and SCCPTCPSCCP: GTT, Ext MTP (Supports CL or CO)Message Discrimination & distributionTCAP: Query and Response (CL or CO )MTP 3: Routing within SPCMTP2: Node to node delivery
SS 7 ArchitectureSSP, STP and SCP
SS 7 Logical Network
MAPMAP messages are carried by TCAP when dealing with Database centre.MAP Sessions: Open, Close. Message Types: Request, Response, Notification andConfirmation.
GSM Call flow
GSM Logical Channels
Authentication and Ciphering
Identity (IMSI) checking
Call Origination 2929
MSRN UsageOur HLR Knows where our Customer is,Only our GMSC can inquire our HLR
GPRS Protocol Stack
MAC1. MAC arbitrates access to the shared medium between multiple MSs and GPRS network.• Uplink: Managing limited resourcesSlotted Aloha• Downlink: Queuing and Scheduling of access attempts.• Priority handling between data flows of one UE• Priority handling between UEs by means of dynamic scheduling—Downlink• Channel mapping• Traffic Volume monitoring
LLCProvide a reliable logical link between MS and SGSN.LLC messages are transparent to RAN.Transmission in Asynchronous Disconnected Mode andAsynchronous Balanced ModeCiphering.Transfer of PDUs of Higher LayersC-Plane: attach, authentication and PDP activationU-Plane: carry actual data.Can be AM or UM
SNDCP• Transparent over BSS. Used only in U-Plane•multiplexing of PDPs. Can be AM or UM•compression of user data (including IP header compression) RFC 1154 & 2507•segmentation of data packets to be passed to the LLC layer.
Frame RelayMeshed N/W Frame Relay
Frame RelaySpeed up to 2 Mbps.Simple.Superseded by ATM
BSSGPTransport both control and User data.Provide the required QoS.One-to-one mapping of BSSGP between SGSN and BSS.
BSSGP Data Frames
GTP1. GTP-U and GTP-C.2. Uses TCP for Reliable link3. Uses UDP for non-Reliable link
IP, TCP and UDPIP: IPv4 or IPv6. Datagram Service. Class full or Class lessAddressing.TCP: Connection Oriented.Ack ARQ. Sequence Number Checking.Three-way handshake. Point-to-Point AddFlow Control and Congestion Control.UDP: Connection less.Used for Delay Sensitive applications.Supports Multicast Addressing.
GPRS Logical Channels
PDP Context Activation
Data Transfer from MS
Data Transfer to MS
Web Access in GPRS
PDP Context Deactivation
R99 Protocol Stack
MACLogical to Transport ConversionMac-b located at Node-BMac-c/sh and Mac-d are at SRNC.
MAC functionalities1. Mapping between logical channels and transport channels• Selection of appropriate TF (from the TFCS) for each Transport Channel, depending on the instantaneous source rate• Priority handling between data flows of one UE• Priority handling between UEs by means of dynamic scheduling— Downlink• Identification of UEs on common transport channels• Multiplexing/demultiplexing of higher layer protocol data units (PDUs)• Traffic volume monitoring—Down link• Dynamic Transport Channel type switching• Ciphering—RLC (TM)• Access Service Class (ASC) selection for RACH transmission
RLC1. Transparent mode (Tr) , Unacknowledged Mode (UM) or Acknowledged Mode (AM)2. Tr and UM RLC entities are defined to be unidirectional, whereas the AM-mode entities are described as bidirectional3. Tr—Voice Call Video Call, UM—VOIP, Streaming
RLC functionalities1. Segmentation and reassembly2. Concatenation3. Padding4. Transfer of user data5. Error correction----ARQ6. In-sequence delivery of higher layer PDUs7. Duplicate detection8. Flow control9. SN check (unacknowledged data transfer mode).10. Ciphering is performed in the RLC layer for acknowledged and unacknowledged modes.11. Suspend/resume function for data transfer
RRC1. Broadcast of system information• Paging and notification• Initial cell selection and reselection• Establishment, maintenance and release of an RRC connection• Establishment and release of Radio bearers• Control of ciphering• Integrity protection of signalling messages• UE measurement reporting and control of the reporting• RRC connection mobility functions• Support of SRNS relocation• Support for downlink outer loop power control in the UE• Open-loop power control• CBS-related functions (BMC)• Handovers---preparation and execution• Control of requested QoS• Routing of Higher layer PDUs (Direct transfer)• MBMS control
BMCBMC: Broadcast/Multicast Control ProtocolSMS-CB service4. Storage of CB5. Traffic volume monitoring and radio resource request for CBS6. Scheduling of BMC messages7. Transmission of BMC messages to UE
PDCP PDCP: Packet Data Convergence Protocol3. PS Domain4. PDCP contains compression methods, which are needed to get better spectral efficiency over radio interface.5. IP Packet header compression. Eg: 40 bytes for IPv4 and at least 60 bytes for IPv6. (RFC 2507)6. Transfer of user data
Non Access Stratum
Protocol Interworking architectureTransport : Carry Signaling and User data.Radio N/W : Establish, maintain and Release RB.System: Create Communication with Core network.
HSDPA user plane Protocol ArchitectureFast Node-B SchedulingH-ARQ ,Incremental RedundancySoft Buffer at Node-B and UERetransmission at N/W borders No Soft Handover
HSUPA Protocol Stack
HSUPA user plane protocol ArchitectureMac-es/e : Uplink SchedulingMac-e: Hybrid ARQ , BufferMac-es : In-sequence delivery (Soft Handover)RLC re transmissions may take place if Physical layer retransmissions is exceeded initiated by RNC.
References1. 3G TS 25.321, MAC Protocol Specification.2. 3G TS 25.322, RLC Protocol Specification.3. 3G TS 25.323, PDCP Protocol Specification4. 3G TS 25.331, RRC Protocol Specification5. 3G TS 25.324, Broadcast/Multicast Control Protocol (BMC) Specification6. 3G TS 25.302, Services Provided by the Physical Layer7. 3GPP TS 25.331 RRC specification8. 3GPP TS 25.413 RANAP9. 3GPP TS 25.423 RANSAP10. 3GPP TS 25.433 NBAP11. GSM.System.Engineering.-.Artech BOOK, by Asha Mehrotra.12. GPRS BOOK-MC-HIL by R.J. Bates.13. WCDM for UMTS-Wiley –H.Holma and A.Toskala14. SS7 –MC-HILL by Travel Russel