GPRS

GPRS : 

GPRS General Packet Radio Service

OVERVIEW : 

GPRS EDGE UMTS OVERVIEW

Contents : 

Contents INTRODUCTION SERVICES ARCHITECTURE MOBILITY MANAGEMENT SESSION MANAGEMENT RADIO RESOURCE MANAGEMENT

INTRODUCTIONWhat is GPRS? : 

General Packet Radio Service a way to extend packet transfer up to the mobile station(MS) Packet switched data on top of GSM network Applies packet radio principle to transfer user data packets in an efficient way between MS & external packet data network Goals of GPRS: Efficient bandwidth usage for bursty data traffic (e.g. Internet) Higher data rates New charging models Initially specified by European Telecommunication Standard Institute (ETSI) Migration Path to 3G Networks INTRODUCTIONWhat is GPRS?

Features : 

Features New Data Services High Speed (Data Rate 14.4 – 21.4*8=171.2 kbps) Efficient use of radio bandwith (Statistical Multiplexing) Circuit switching & Packet Switching can be used in parallel Constant connectivity Radio channels are shared by multiple users Always on, always connected

High Data Rate : 

Radio channel width = 200 kHz Radio channel carries digital data stream = 271 kbps This is divided into 8 time slots each carrying 34 kbps After Correlation data rate per time slot = 14 kbps GPRS can combine upto 8 time slots giving data rate of 114 kbps High Data Rate

GPRS in NEPAL : 

NTC –GPRS, data rate = 153.4 kbps NCELL – EDGE, data rate = 270kbps GPRS in NEPAL

GSM Data Services : 

CSD - Circuit switched data (9.6 kbps) HSCSD - High Speed CSD (n x CSD kbps) GPRS - General packet radio service (up to 171.2 kbps) EDGE - Enhanced Data service for Global Evolution (up to 384 kbps) UMTS – Universal Mobile Telecommunication System (up to 2Mbps) GSM Data Services

GPRS Services : 

GPRS Services Offers end-to-end packet switched data transfer Bearer Services PTP - Point-To-Point service PTM - Point-To-Multipoint service Supplementary Services SMS - Short Message Service CFU - Call Forwarding Unconditional CFNR - Call Forwarding on mobile subscriber not reachable Quality of Service(QoS) GPRS allows defining QoS profiles Service precedence, reliability, delay, throughput

USES : 

Everything you can do on the Internet today but Anywhere, Anytime, Anyplace: eCommerce -> mCommerce WAP and iMode applications (mobile internet browsing) Mobile Corporate Intranet (online publishing, corporate automation, …) File sharing (MP3, MPEG4, …) P2P Messaging (IM, E-mail, SMS) Others: Active Personal Information Management USES

GPRS Terminals : 

Class A – support simultaneous GPRS and GSM voice services with two channels Class B – support either GPRS and GSM voice services with simultaneous network attachment Class C – support only GPRS service GPRS Terminals

GPRS Architecture : 

GPRS Architecture

Acronyms : 

MS: Mobile Station BSC: Base Station Controller BTS: Base Trans-receiver Station MSC: Mobile Switching Controller GMSC: Gateway Mobile Switching Controller PSTN: Public Switched Telephone Network VLR: Visited Location Register EIR: Equipment Identity Register AUC: Authentication center HLR: Home Location Register PLMN: Public Land Mobile Network E.g., GSM network PDN: Packet Data Network E.g., IP network, Internet, intranet Acronyms

Network Interace : 

Network Interace

SGSN : Serving GPRS Support Node : 

Delivers data packets to mobile stations & vice-versa Detect and Register new GPRS MS in its serving area Packet Routing, Transfer & Mobility Management Authentication, Maintaining user profiles Its location register stores location info. & user profiles SGSN : Serving GPRS Support Node

Slide 16: 

GGSN : Gateway GPRS Support Node Interfaces GPRS backbone network & external packet data networks Converts the GPRS packets from SGSN to the PDP format Converts PDP addresses change to GSM addresses of the destination user Stores the current SGSN address and profile of the user in its location register Performs authentication Many-to- many relations among SGSNs & GGSNs

PCU : Packet Control Unit : 

Allow MT & SGSN to exchange data packets Provides dynamic radio resources allocation for GSM CS and GPRS Could be located anywhere between the SGSN and the BTS; usually located at the BTS Segmentation of LLC Frame Automatic Request(ARQ) Physical channel scheduling PCU : Packet Control Unit

GPRS Protocol Stacks : 

BSS elements manage everything related to radio resource, mobility and session management GPRS Protocol Stacks

Mobile equipment – Three Types : 

Mobile equipment – Three Types

Location Management - Mobile States : 

Location Management - Mobile States

Routing Area Update : 

GSM Location Area(LA) is divided into several Routing Areas(RA) RA consists of several cells SGSN is informed when MS moves to a new RA MS sends a “Routing Area Update Request” to its assigned SGSN Types - Intra SGSN Routing Area Update - Inter SGSN Routing Area Update Routing Area Update

Mobility Management : 

Consists of two levels: Micro mobility management : Tracks the current RA or cell of MS It is performed by SGSN Macro mobility management : Keep tracks of MS’s current SGSN Stores it in HLR, VLR, and GGSN Mobility Management

Mobility Management – GPRS Attach : 

Mobility Management – GPRS Attach

Session Management : 

Packet Data Protocol (PDP)context: – set of information stored in mobile, SGSN and GGSN – allow packet data transfer between a certain type of network and the mobile PDP context contains: Session Management

Session Management - PDP Context Activation : 

Session Management - PDP Context Activation

Session Management - Data Transfer : 

Session Management - Data Transfer

Radio Resource Management - Channels : 

Logical Channel - Traffic Channels - Signaling Channels (Control Channels) Physical Channels Radio Resource Management - Channels

Logical Channels : 

Logical Channels

Physical Layer : 

Physical Layer

Logical Signalling for GPRS : 

Logical Signalling for GPRS

GSM VS GPRS : 

GSM VS GPRS Circuit - Switched voice and data service Network nodes are switching centers(MSCs). Each MSC is in Charge of The MTs in its control area. Gateway MSC BSS Packet – switched data services Network nodes are IP routers enhanced with mobility management functionalities GGSN BSS enhanced with a PCU

Slide 32: 

5. User Identified by MSISDN(phone no.) 6. One operation state 7. Location update whenever MT changes LA 8. For voice traffic 9. Physical channels : FDMA/TDMA 10. An MT cam occupy 1 TCH only and that TCH is occupied by the MT for the whole call duration 11.Logical channels; TCHs (1 time slot) and control channels(BCCH etc) 5. User identified by an IP address 6. Three operational states 7. Finer localization( LA divided into Routing Areas composed of several cells) 8. For both data and signaling in the fixed part of the network: L1(e.g. SDH); L2(ATM or Frame Relay):L3(IP) 9. Physical channels: FDMA/TDMA 10. An MT can occupy up to 8 slots. A traffic channel is assigned to an MT just for the time of a packet transmission. Up to 8 MTs can be multiplexed over the same time slot 11. Logical Channels PDTCHs (packet Data TCHs) and new Control Channels (PBCCH, etc)

GPRS Network from the Internet : 

GPRS Network from the Internet

EDGE : 

Enhanced Data rates for Global Evolution Up to 348 kbps Initially developed for operators who failed to get UMTS spectrum Uses different modulation to squeeze more data into same timeslot as GPRS Requires hardware support in both the handset and the BTS and software in the BSC EDGE

UMTS : 

Universal Mobile Telecommunications System Provides: – More of the same as GSM/GPRS/EDGE – Up to 2 Mbps promised data rate – 144 kbps a more realistic bit rate – VoIP instead of PSTN calls? – Video phone, other multimedia services – Global roaming (almost) – Convergence for the operators – More effective radio spectrum usage UMTS

Slide 36: 

GSM Architecture / GSM Radio Local area network Server Router Serving GPRS Support Node (SGSN) Gateway GPRS Support Node (GGSN) GPRS INFRASTRUCTURE HLR/AuC MSC BSC BTS Packet network PSTN Packet network SS7 Network Packet network Data network (Internet) Packet network Inter-PLMN Backbone network Border Gateway (BG) Gb Gr Gd Gi.IP Firewall Firewall Um SMS-GMSC Gr Gd Gs Gs Gp Gn Gn EIR MAP-F A Gc

UMTS Architecture / WCDMA : 

UMTS Architecture / WCDMA Local area network Server Router Serving GPRS Support Node (SGSN) Gateway GPRS Support Node (GGSN) GPRS INFRASTRUCTURE HLR/AuC MSC RNC Node B Packet network PSTN Packet network SS7 Network Packet network Data network (Internet) Packet network Inter-PLMN Backbone network Border Gateway (BG) Iu Gr Gd Gi.IP Firewall Firewall Uu SMS-GMSC Gr Gd Gs Gs Gp Gn Gn EIR MAP-F Iu Gc

UMTS… : 

UMTS…

UMTS Radio Access Network(RAN) : 

UMTS requires a new Radio Access Network – The Wideband CDMA-based UTRAN (Universal Terrestrial RAN) provides the higher data rates – 1885-2025 MHz (uplink) – 2110-2200 MHZ (downlink) – The GSM/EDGE GERAN can be used with UMTS – Might stay for a long time in the less populated areas New names for new components – Radio Network Controller – Base Station – User Equipment New functions – Cell breathing – Soft handover UMTS Radio Access Network(RAN)

4G - after UMTS : 

A combination of UMTS, WLAN, Bluetooth and other similar technologies is often interpreted as 4G No formal definition yet Data rates of 20 - 100 Mbps? WLAN is already coming to the new high end terminals, enabling e.g. VoIP 4G is more about the services than the actual networking technologies 4G - after UMTS