����PRESENTATION ON �GPRS

• BRANCH-E & TC ENGG
• SUBJECT- ADVANCE COMMUNICATION ENGINEERING
• CHAPTER – 6 – WIRELESS COMMUNICATION
• TOPIC- GPRS
• SEM-6^TH
• FACULTY – Er. UMASHANKAR PANDA(Sr. LECT. E & TC ENGG DEPARTMENT)
• AY-2021-2022, SUMMER-2022

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1. INTRODUCTION TO GPRS

1.1. What is GPRS ?

1.2. GPRS access interfaces and reference points

1.3. How is GPRS seen by external networks and GPRS users

1.4. Air interface resources

1.5. GPRS characteristics

1.6. Applications

1.1. WHAT IS GPRS ?

• Part of GSM phase 2+
• General Packet Radio Service
• General -> not restricted to GSM use (DECT ?, 3rd generation systems ?)
• Packet Radio -> enables packet mode communication over air
• Service, not System -> existing BSS (partially also NSS) infrastructure is used
• Requires many new network elements into NSS
• Provides connections to external packet data networks (Internet, X.25)
• Main benefits
• Resources are reserved only when needed and charged accordingly
• Connection setup times are reduced
• Enables new service opportunities

1.2. GPRS ACCESS INTERFACES AND REFERENCE POINTS

• GPRS provides packet switched connections from MS to packet data networks (PDN)
• Different operator’s GPRS networks are connected through Gp interface

1.3. HOW IS GPRS SEEN BY EXTERNAL NETWORKS AND GPRS USERS?

1.4. AIR INTERFACE RESOURCES

An example of occupied TCH capacity by CS traffic during busy hour with n% blocking

Capacity occupied by CS traffic

Free

Capacity

GPRS "steals" any TCH

capacity not used by CS

traffic

1.5. GPRS CHARACTERISTICS

GPRS uses packet switched resource allocation

• resources allocated only when data is to be sent/received

Flexible channel allocation

• one to eight time slots
• available resources shared by active users
• up and down link channels reserved separately
• GPRS and circuit switched GSM services can use same time slots alternatively

Traffic characteristics suitable for GPRS

• Intermittent, bursty data transmissions
• Frequent transmissions of small volumes of data
• Infrequent transmission of larger volumes of data

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1.6. APPLICATIONS

• Standard data network protocol based
• IP based applications
• WWW, FTP, Telnet, ...
• Any conventional TCP/IP based applications
• X.25 based applications
• Packet Assembly/Disassembly (PAD) type approach
• GPRS specific protocol based
• Point-to-point applications
• Toll road system, UIC train control system
• Point-to-multipoint applications
• Weather info, road traffic info, news, fleet management
• SMS delivery (GPRS as a bearer for SMS)

2. GPRS ARCHITECTURE

2.1. Interfaces, reference points and network elements

2.2. Functional view on GPRS

2.3. Subscription of GPRS service

2.4. New network elements

2.4.1. GGSN

2.4.2. SGSN

2.4.3. Other elements

2.4.4. GPRS backbones

2.5. GPRS Mobile classes

2.6. MS multislot capabilities

2.1. INTERFACES, REFERENCE POINTS AND NETWORK ELEMENTS

2.2. FUNCTIONAL VIEW ON GPRS

2.4.2. SERVING GPRS SUPPORT NODE

SGSN

• Functionally connected with BSC, physically can be at MSC or BSC site
• One for few BSCs or one (or few) per every BSC
• One SGSN can support BSCs of several MSC sites�
• Main functions
• Authenticates GPRS mobiles
• Handles mobile’s registration in GPRS network
• Handles mobile’s mobility management
• Relays MO and MT data traffic
• TCP/IP header compression, V.42bis data compression, error control MS- SGSN (ARQ)
• Collect charging information of air interface usage

3.3. DATA TRANSFER: BASIC RULES (1/4)

• SGSN:
• Does not interpret user data, except
• SGSN may perform TCP/IP header compression
• Does not interpret source or destination addresses
• Sends all packets to specified GGSN that handles the PDP context
• GGSN:
• Performs optional filtering
• Decides where and how to route the packet

3.3. DATA TRANSFER (2/4)

Mobile originated (left when MS in HPLMN, right when in VPLMN, no filtering/screening)

3.3. DATA TRANSFER (3/4)

Mobile terminated (left when MS in HPLMN, right when in VPLMN, with/without filtering/screening)

3.3. DATA TRANSFER (4/4)

Mobile originated and terminated (left MSs in same PLMN, right MSs in different PLMN)

6.2 GPRS SPECIFICATIONS

THANK YOU