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UMTS. GSM GPRS services upto 160 kbit/s. PDS services low bit rates. EDGE. GSM HSCSD services upto 38.4 kbit/s (later up to 64 kbit/s). GSM CS data services upto 9.6 kbit/s. 91/92. GSM Data evolution. Functionality. 98. 99/00. 02. GPRS evolution towards 3 rd Generation.
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UMTS GSM GPRS services upto 160 kbit/s PDS services low bit rates EDGE GSM HSCSD services upto 38.4 kbit/s (later up to 64 kbit/s) GSM CS data services upto 9.6 kbit/s 91/92 GSM Data evolution Functionality 98 99/00 02
GPRS evolution towards 3rd Generation • HSCSD “High Speed Circuit Switched Data” • 1st step in GSM Phase 2+ that clearly increase achievable data • Rates in the GSM System • 14.4kbps Channel Coding =115.2kbps for 8 Tsl • Maximum data rate is limited to 64kbps due to CN a A-Interface • limitation • Precondition: • Modify GSM Network to support HSCSD in BSC & MSC • Handsets has to support Multislot Capabilities • Today HSCSD (Data Cards)Handsets support 4 Tsl in Downlink • and up to 2 Tsl in Uplink Direction
GPRS evolution towards 3rd Generation • Depending on the Cell Configuration amount of Users is • restricted • Multiple User cannot share a Tsl at the Air Interface • Depending on the Bearer Nature “Circuit Switched” a Tsl • is dedicated to a Subscriber • Amount of Subscriber per Tsl is limited to 1 • Circuit Switched Data has a long access time • Call Charging is based on connection time
GPRS evolution towards 3rd Generation • GPRS “General packet Radio System” • Connections do not reserve resources permanently, which is • Highly efficient for applications with a bursty nature • Short access time to the Network • Charging model can be based on transmitted volume • GPRS brings packet switched bearer services to the existing • GSM System • User can Access Public Data Network directly using their • Standard protocol addresses (IP, X.25) • GPRS Mobile can use between 1-8 channels over the air interface depending on the MS capabilities
GPRS evolution towards 3rd Generation • Resource allocation is dynamic and dependent on demand and • Resource Availability • Packets can be sent on idle time between speech call depending MS class types • Possible traffic types • point to point • point to multipoint (postponed to Release 4&5) • SMS capability • Anonymous access (planned) • Maximum Theoretical throughput per MS using 8 Tsl without Error Correction is 160kbps
GPRS Logical Architecture SMS-GMSC SM-SC SMS-IWMSC E C Gd MSC/VLR HLR D Gs Gc A Gb Gr Gi TE PDN TE MT BSS SGSN GGSN Gn R Um Gp Gf EIR GGSN Other PLMN Signaling Interface Signaling and Data Transfer Interface
Traffic & Signaling Signaling GPRS Logical Architecture ISDN/PSTN EIR Um GMSCMSC/VLR BTS Gf AUC Gr HLR Gs BSC External IP Network Gb Notebook & GPRS mobile SGSN Gn IP-Backbone Network External IP Network GGSN Gi BTS - Base Transceiver Station BSC - Base Station Controller MSC - Mobile Switching Centre HLR - Home Location Register SGSN - Serving GPRS Support Node GGSN - Gateway GPRS Support Node PTM-SC - Point-to-Multipoint Service Centre External X.25 Network PTM-SC
GPRS Network Node Functionality • SGSN and GGSN are IP based packet switching nodes • SGSN supports basic mobility management, session management, subscription checking, charging • GGSN supports session management, charging and provides interconnect points to ISPs (Internet Service Provider) • BSC (PCU) supports the Radio Link- and MediumAccess Control protocol (RLC/MAC) • BTS supports new channel coding and interleaving • HLR supports subscriber data management
GPRS Mobiles • Class A: Simultaneous usage of Circuit- and Packet switched services (2 TRX=Dual Transfer Mode DTM is precondition). • Class B: Automatic choice of service, Circuit- or Packet switched, but only one at a time (1 TRX). Suspension/resumption of GPRS services at setup/release of CS connection. • Class C: Manually selected use of either Circuit- or Packet switched service. Special case is a packet only MS (1TRX).
Class Download Upload Max.slots 1 1 1 2 2 2 1 3 3 2 2 3 4 3 1 4 5 2 2 4 6 3 2 4 7 3 3 5 8 4 1 5 9 3 2 5 10 4 2 5 11 4 3 5 12 4 4 5 13 3 3 unlimited 14 4 4 unlimited 15 5 5 unlimited 16 6 6 unlimited 17 7 7 unlimited 18 8 8 unlimited 19 6 2 unlimited 20 6 3 unlimited 21 6 4 unlimited 22 6 4 unlimited 23 6 6 unlimited 24 8 2 unlimited 25 8 3 unlimited 26 8 4 unlimited 27 8 4 unlimited 28 8 6 unlimited 29 8 8 unlimited GPRS Mobile Station “Multislot Classes”
GPRS Transmission Plan Application IP / X.25 IP / X.25 SNDCP SNDCP GTP GTP UDP/ TCP UDP/ TCP LLC LLC RLC RLC BSSGP BSSGP IP IP Frame Relay Frame Relay MAC MAC L2 L2 GSM RF GSM RF L1bis L1bis L1 L1 MS BSS (PCU) SGSN GGSN Gi Gb Gn Um
GPRS Handset IP Address Assignment • Mobile User connects to specified APN • APN is configured in the GGSN • Kinds of Handset IP address assignment • GGSN pool per APN Subscriber IP Address assignment • external DHCP Server • Intranet DHCP Server • Fixed IP Address Assignment in the HLR per Subscriber and APN (not or!!)
GPRS Routing and Address Plan IPv4 ‣used In GPRS Backbone (public & private) ‣used for Handsets (public & private) IPv6 ‣Backbone can support with Release 99 implementation ‣current used GPRS capable Handsets does not support IPv6 ‣1st steps visible for UMTS Handsets only
GPRS Routing and Address Plan • Further necessary Routing Instrument for GPRS • TLLI=Temporary Logical Link ID • Routing Area • Location Area
GPRS Routing and Address Plan Gb Interface Gn Interface SGSN<->BSC SGSN<->GGSN BVCI /LA/RA GTP Address Tunnel ID =IMSI Handset IP Handset IP TLLI
Avoid Collision at the Air Interface Data Transmission divided in to Up- and Downlink Data Traffic
GPRS Quality of Service Profile • 1)Delay for packets of 128 octets; • Delay class 1 (mean 0.5 sec, 95% < 1.5 sec) • Delay class 2 (mean 5 sec, 95% < 25 sec) • Delay class 3 (mean 50 sec, 95% < 250 sec) • Delay class 4 (unpredicted) • 2) Reliability • Reliable data transfer (retransmission, delay) • Unreliable data transfer (no retrans., small delay) • Unreliable data transfer, erroneous data discarded (no retrans., small delay, data loss)
GPRS Quality of Service Profile • 3) Priority • Priority class 1 (highest priority) • Priority class 2 • Priority class 3 • Priority class 4 (lowest priority) • 4) Mean and 5) Peak throughput
further Steps • Packet Handling (PBCCH/PCCCH) • QoS Negotiation (Air <->GGSN) • Increasing USF Granularity • IPv6 • Network Mode Changes to decrease MS signalling • MS with higher Multislot Capabilities • Extended MAC Modes • Technology • EDGE GPRS with 8PSK modulation • UMTS