1. GPRS/EDGE OVERVIEW

2. Course contents GPRS Background and Evolution GSM/GPRS network
GPRS Architecture
IP Addressing in GPRS
GPRS Air Interfaces
MS types and Coding Schemes
Mobility Management
PDP Context Activation Sequence
GPRS Roaming
GPRS Charging
Practical Demonstration of GPRS

3. GPRS BACKGROUND AND EVOLUTION

4. GPRS BACK GROUND
With Mobile penetration reaching its full potential, GPRS gives Mobile operators competitive edge and optimum use of the infrastructure.
SMS is a good example of just how hungry users are for data services.
The main Objective of GPRS is to offer the access to standard data networks, using protocols e.g. TCP/IP and X.25
Transactions such as Credit Card checks and a variety of telemetric applications benefit from the fast session set-ups.
GPRS enables efficient use of radio resources by allowing many data users to share the same interface on a statistical basis.
The main benefits of GPRS are that it reserves radio resources only when there is data to be sent
Mobile users doesn’t have to connect to the network each time he wants to transfer the data, he can stay connected all day.

5. Evolution from GSM to 3G The GSM Growth Phases 3G EDGE GPRS 2.5G HSCSD

6. GSM Evolution 2G 2.5G 3G GSM GPRS EDGE UMTS UMTS 5 MHz carrier
2 Mbps peak data rates
New IMT GHz spectrum
GSM
200 KHz carrier
8 full-rate time slots
16 half-rate time slots
GPRS
200 KHz carrier
115 Kbps peak data rates
EDGE
200 KHz carrier
Data rates up to 384 Kbps
8-PSK modulation
Higher symbol rate
HSCSD
HSCSD
Circuit-switched data
64 Kbps peak data rates

7. MAIN ADVANTAGES FOR OPERATORS
More Revenue :
By providing more than a mobile connection.
Also operator can charge on the basis of type and amount of content accessed.
Huge Potential Market for Data Sevices :
Mobile Phone and Internet, both are fastest growing technologies and GPRS is the merger of two.
Fast Roll-out and Continuous Network Expansion :
GPRS is an integral part of GSM.
GPRS uses excess voice capacity for data :
GPRS Packets are transmitted in short, free periods between busy hour calls.

8. Free GSM Capacity GPRS packets can be transmitted in2 4 6 8 10 12 14 16
1:00 PM
1:15 PM
1:30 PM
1:45 PM
TCH
03:00
06:00
09:00
12:00
15:00
18:00
21:00
00:00 TC H
GPRS packets can be transmitted in
the short free periods between busy
hour calls
2TRX = 14 Speech TS
2% blocking means
8 Erlang speech traffic Ø
On average 6 TS free !

9. GPRS Vs GSM GPRS Vs GSM 1. SUPPORTS BOTH CKT. Only circuit switched.
SWITCHED as well as
packet switched service.
2. MS Utilizes Automatic No re-transmission is
retransmission (ARQ) at provided.
data link layer to re-transmit
error frames.
3. Multiple time slots can be Single time slot per user.
allotted to a single user
4. One time slot can be allotted Single time slot per user.
to several users.
5. Charging/ billing more complex Simple time-based billing.
(Volume based, Q.O.S. based)

10. TYPICAL GPRS SERVICES * Communications- E-mail, fax,
intranet/ internet access.
* Value added services Information services, games,
e-commerce.
* Location-based applications - Navigation, traffic conditions,
airline/rail schedule, location finder.
* Vertical applications Freight delivery, fleet management,
sales-force automation
* Location sensitive A user nearing a cinema hall or
Advertising a restaurant receives flashes of
advertisement

11. GPRS NETWORK ELEMENTS

12. The Main elements of GSM are:
GSM NETWORK ELEMENTS
The Main elements of GSM are:
NSS :
MSC
VLR
HLR (Includes Authentication Center and Equipment Identity Register)
BSS :
BSC
BTS
Transcoder
NMS
Fault Management
Configuration Management
Performance Management

13. GPRS Network Elements Network Element Software Hardware
SGSN SG1 DX Platform
GGSN G1 IP650
Firewall Checkpoint IP650
Ethernet Switch N/A Cisco Catalyst
DNS HP-UX HP 9000 A class
CG HP-UX HP K class
Border Gateway BGP IP650
DHCP HP-UX HP 9000 A class

14. GPRS ARCHITECTURE

15. GPRS Interface

16. SGSN Role Authentication, Authorization GTP tunneling to GGSN
Ciphering & compression
Mobility Management
Session Management
Interaction with HLR, MSC/VLR
Charging & statistics
NMS interfaces

17. GGSN Role Interface to external data networks
Encapsulate in GTP and forwards end user data to right SGSN
Routes mobile originated packets to right destination
Filters end user traffic
Collects charging and statistic information for data network usage

18. GPRS AIR INTERFACES

19. Different GPRS Capacity Types
Circuit
Switched
TRX 1
CCCH TS TS TS TS TS TS TS
Territory
TRX 2
Packet TS TS TS TS TS TS TS TS TS TS TS TS
Switched
Territory
Additional
Dedicated
GPRS
GPRS
GPRS
Capacity
Capacity
Capacity
Territory border moves based
on Circuit Switched traffic load

20. GPRS MS CLASS & CODING SCEMES

21. MS Class
CLASS A: Supports simultaneous attach, simultaneous activation, simultaneous monitor, simultaneous invocation, and simultaneous traffic.
CLASS B: Simultaneous traffic shall is not supported. The mobile user can make and/or receive calls on either of the two services sequentially but not simultaneously. The selection of the appropriate service is performed automatically
CLASS C: Supports only non-simultaneous attach. Alternate use only.
The status of the service which has not been selected is detached, that is, not reachable.

22. GPRS Channel Coding Schemes
GPRS can also increase the data rate in a single timeslot. The coding schemes listed above are based on the current scheme used for GSM signaling channels (notice a single slot rate of 9.05 in CS1 as opposed to the TCH data rate of 9.6 in GSM).
To increase the data rate, some of the error detection and correction bits are removed from the burst. So CS2 has less C&D bits than CS1, and CS4 has no error protection at all. The consequences of this are that to maintain a call in CS4 it is necessary to have excellent signal quality. This can only be achieved at positions closer to the BTS. Therefore, the cell radius is greatly reduced when using CS3 and CS4.
The BSS automatically upgrades and downgrades the connection among the coding schemes based on the number of erroneous packets it receives.
In the first release of GPRS, only CS1 and CS2 are implemented. This is because CS3 and CS4 require structural changes to the Abis interface. These data rates will not fit into a 16kbit/s channel.

23. GPRS MOBILITY MANAGEMENT

24. Mobility Management State
GPRS
Attach
/ Detach
Idle
Ready
READY
Timer Expiry
Packet
Standby
STANDBY
TX/RX
Timer Expiry
MS location known to
MS location known to
cell level.
MS location
SGSN level.
MS is transmitting or has
not known.
MS is capable of receiving
just been transmitting.
Subscriber is not
Point-to-Multipoint data
MS is capable of receiving
reachable by the
and being paged for
Point-to-Point data and
GPRS NW.
Point-to-Point data
Point-to-Multipoint data.

25. Routing Area
RAI = MCC+MNC+LAC+RAC

26. GPRS Mobility Management
Routing Area :
The RA is a new concept for tracing the MS location.
Cell =< RA =< LA served by one SGSN
RAI = MCC + MNC + LAC + RAC
Every time the MS sees the new RAI is has to initiate the RA
update procedure.

27. GPRS Mobility Management
Mobility Management States :
The IDLE State is when the MS is not connected.
The Standby State is when the MS is connected to the GPRS Network
The Ready State is when the MS is ready to connect to the external IP Network.
Changing between states can be initiated from the MS, from the network and from the timers set.

28. PDP CONTEXT ACTIVATION

29. PDP Context Activation Accessing the HLR
(1) MS sends "Activate PDP Context Request" to SGSN
Access Point Name
PDP Type (IP)
PDP Address (empty == dynamic)
HLR 2.
BTS
BSC
SS7 1.
(2) SGSN checks against HLR
Access Point Name
Dynamic / static IP address
APN=
"Intranet.Ltd.com"
SGSN
DNS
GPRS
Backbone
IP Network
Access
Point
Intranet
GGSN
Internet
Access Point Name = Reference to an external packet data network the user wants to connect to

30. ADDITIONAL GPRS SECURITY FEATURES ARE
SECURITY IN GPRS
GPRS SYSTEM HAS INHERITED THE GSM PH-2 SECURITY FUNCTIONS
Authentication of the subscriber
IMEI Checking
User Identity Confidentiality (TMSI in GSM, P-TMSI in GPRS)
Ciphering of the data traffic between MS and SGSN
Private IP Addressing in the GPRS backbone.
Ciphered links and authentication between nodes in the GPRS Backbone.
Screening of packets coming from the external networks (Firewall).
(P-TMSI is used to derive the Temp Logical Link Identity (TLLI))
ADDITIONAL GPRS SECURITY FEATURES ARE

31. EGPRS = GPRS + EDGE modulation
The Abbreviation
GPRS = General Packet Radio System
EGPRS = GPRS + EDGE modulation

32. EDGE – Provide 3G services today
Provide 3G services with existing licenses
New modulation optimized for wireless data services
Link adaptation: Take highest possible rate
Covered by existing GSM licenses
Same channel structure, network infrastructure, frequency
planning and protocol as today’s GSM

33. Evolution to EDGE SMS G/IW MSC HLR AUC BTS BSC MSC/VLR EDGE TRU SGSNGd
AUC M S
BTS
PUC
BSC
MSC/VLR Gr
ISP Network Gs Gb
EDGE TRU M S Gi
SGSN
GGSN Gn Gn
CorporateNetwork
Backbone Network

34. EDGE increases capacity
voice
voice
voice
voice
voice
Standard GSM Transceiver
voice
voice
voice
voice
voice
Free TS
Free TS
Data
EDGE Transceiver

35. System upgrade for EDGE
EDGE TRU B S C R B S
BSC Software Upgrade
EDGE enabled RBS

36. What EDGE would mean to subscribers
Streaming Applications
Very high speed downloads
Corporate Intranet connections
Quicker MMS
Video Phone
Vertical corporate applications – Video
Conference, Remote presentations

37. Thank You!