Transcript No Slide Title

GSM Data evolution
Functionality
UMTS
GSM GPRS services
upto 160 kbit/s
PDS services low bit rates
GSM HSCSD services upto 38.4
kbit/s (later up to 64 kbit/s)
GSM CS data services
upto 9.6 kbit/s
© Sunrise 16.07.2015
91/92
98
99/00
02
EDGE
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
© Sunrise 16.07.2015
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
© Sunrise 16.07.2015
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
© Sunrise 16.07.2015
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
© Sunrise 16.07.2015
GPRS Logical Architecture
SMS-GMSC
SMS-IWMSC
E
SM-SC
C
Gd
MSC/VLR
HLR
D
Gs
A
TE
MT
R
Gb
BSS
Um
Gc
Gr
SGSN
Gp
Gi
PDN
GGSN
Gn
Gf
EIR
GGSN
Other PLMN
© Sunrise 16.07.2015
Signaling Interface
Signaling and Data Transfer Interface
TE
ISDN/
PSTN
GPRS Logical Architecture
Um
GMSC
MSC/VLR
BTS
Notebook & GPRS mobile
Gb
AUC
Gr
Gs
BSC
Gf
EIR
HLR
External
IP Network
SGSN
Gn
Traffic & Signaling
Signaling
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
© Sunrise 16.07.2015
IP-Backbone
Network
PTM-SC
GGSN
Gi
External
IP Network
External
X.25 Network
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 Medium
Access Control protocol (RLC/MAC)
• BTS supports new channel coding and interleaving
• HLR supports subscriber data management
© Sunrise 16.07.2015
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).
© Sunrise 16.07.2015
GPRS Mobile Station “Multislot Classes”
Class
© Sunrise 16.07.2015
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
Download
Upload
1
2
2
3
2
3
3
4
3
4
4
4
3
4
5
6
7
8
6
6
6
6
6
8
8
8
8
8
8
1
1
2
1
2
2
3
1
2
2
3
4
3
4
5
6
7
8
2
3
4
4
6
2
3
4
4
6
8
Max.
slots
2
3
3
4
4
4
5
5
5
5
5
5
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
unlimited
GPRS Transmission Plan
Application
IP / X.25
IP / X.25
SNDCP
SNDCP
GTP
GTP
LLC
LLC
UDP/
TCP
UDP/
TCP
RLC
RLC
BSSGP
BSSGP
IP
IP
MAC
MAC
Frame
Relay
Frame
Relay
L2
L2
GSM RF
GSM RF
L1bis
L1bis
L1
L1
MS
© Sunrise 16.07.2015
Um
BSS (PCU)
Gb
SGSN
Gn
GGSN
Gi
GPRS Routing <->Transmission Plane
© Sunrise 16.07.2015
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!!)
© Sunrise 16.07.2015
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
© Sunrise 16.07.2015
GPRS Routing and Address Plan
Further necessary Routing Instrument for GPRS
TLLI=Temporary Logical Link ID
Routing Area
Location Area
© Sunrise 16.07.2015
GPRS Routing and Address Plan
Gb Interface
SGSN<->BSC
Gn Interface
SGSN<->GGSN
Handset IP
Handset IP
TLLI
Tunnel ID =IMSI
BVCI /LA/RA
© Sunrise 16.07.2015
GTP Address
Avoid Collision at the Air Interface
Data Transmission divided in to Up- and Downlink Data Traffic
Uplink
USF0
USF1
USF2
USF3
USF4
USF5
USF06
USF7
Free
TFI5
TFI6
TFI7
Uplink
TFI0
TFI1
TFI2
TFI3
TFI4
Downlink
© Sunrise 16.07.2015
TFI8
GPRS Multiplexing at RLC/MAC Layer
BCCH
CCCH
SDCCH&
SACCH
CS
CS
CS
CS
CS
PS
USF0
USF1
USF2
USF3
Uplink
USF4
USF5
USF6
USF7
© Sunrise 16.07.2015
TFI7
TFI8
TFI2
TFI4
TFI6
TFI1
TFI3
TFI5
TFI0
GPRS Coding Schemes based on RLC/MAC
Coding Rate
Info
(bits)
CRC
(bits)
Abis
Data rate
unchanged (kbps)
R=1/2
(SDCCH)
184
40
yes
9.05
R=2/3
272
16
yes
13.4
R=3/4
320
16
no
15.6
R=1
440
16
no
21.4
© Sunrise 16.07.2015
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)
© Sunrise 16.07.2015
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
© Sunrise 16.07.2015
GPRS Roaming Direct Interconnect
Operator A
Operator B
Leased Line E1
© Sunrise 16.07.2015
GPRS Roaming using IPSEC Tunnel via Internet
Operator A
IPsec Tunnel via
the Internet
© Sunrise 16.07.2015
Operator B
Internet
GPRS Roaming using GRX
Public Internet
MS
Public Internet
Public Internet
Public Internet
MS
BTS
BSC
BSC
SGSN
BTS
GGSN
SGSN
GGSN
DNS
DNS
Charcing GW
Operator A. GPRS Backbone
as HOME OPERATOR
Operator B. GPRS Backbone
as VISITED OPERATOR
Border GW
Root DNS
Info Base
Inter PLMN Backbone Service
network
© Sunrise 16.07.2015
Border GW
Charging GW
GPRS Roaming Scenario using HGGSN
© Sunrise 16.07.2015
GPRS Roaming Scenario using VGGSN
© Sunrise 16.07.2015
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
© Sunrise 16.07.2015