Transcript Cisco Presentation Guide

Mobile
Wireless
Exponential Growth of World Wide
GSM Data Users
in million subscriber
 Growth in mobile data is expected to be 70% p.a. in next 5 yrs
90
80
70
60
50
40
30
20
10
0
innovators
early adaptors
early majority
(Merryl Lynch)
Late majority
~ 1%
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
2
Dramatic Increase of Mobile
Data Volume
UMTS study funded by the European Comission
Mbytes per user per month
data will account for up to 75% of total mobile traffic
 by 2005 up to 40% of people in the EU will be using mobile phones
35
30
25
20
Today
0.8 Mb/user/month
15
10
5
0
1995
N+I_2k
1996
© 2000, Peter Tomsu
1997 1998
1999
2000
2001
01_mobile_wirel
2002 2003
2004
2005
3
Wireless Data Network Drivers
• Information access
• PDAs
• Network computers
• Alpha paging,
information
distribution
• Web/WAP
technology
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
4
Services Most Often Requested
After Basic Wireless Telephony Service
Call Forwarding
37%
Paging
33%
Internet/E-mail
24%
Traffic/Weather
15%
Conference Calling
13%
News
Data
Applications
3%
Source: CTIA Web Page
Peter D. Hart Research Associates, March 1997
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
5
Data Services on Cellular
• Standards for packet services on cellular
are already defined
GSM: GPRS - GSM Packet Radio System
CDMA: IWF and MobileIP
• Both utilize bandwidth over the
backhaul/backbone to gateway devices
• A data network built for packet data
transport can reduce the need to expand
the backbone beyond voice requirements
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
6
Wireless Market Segments
Wireless Market Segments & Partners
Wireless Internetworking
Overview
Residential/
Premise/ Campus
Fixed
Mobile
Broadband Multiservice
IEEE
802.11
BLUE
TOOTH
MMDS
LMDS
Cisco/
Bosch
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
2G+
Cellular
3G
Cellular
Data
Services
Packet
Data/Voice
GPRS
Mobile IP
UMTS
7
Residential WLANs
• Found in office environment for wireless
network access
• Either infrared or radio
• Standards are
Bluetooth
IEEE 802.11
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
8
Fixed Wireless
• Provide high speed wireless link to
connect remote sites
• Point-to-point or point-to-multipoint
• Line-of-sight or non-line-of-sight systems
• Two standards
LMDS – Local Multipoint Distribution System
MMDS
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
9
Mobile Wireless Networks
• Usually digital cellular radion networks
• Provide voice and data services
• 1G – analog transmission
• 2G – digital cellular networks (like GSM)
Circuit switched
• 2G+
HSCSD (circuit switched bundeled timeslots)
GPRS (voice CS, data PS)
• 3G – like UMTS
Completely packet switched voice and data
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
10
GPRS and other Mobile Wireless
Technologies
Technology
Type
Throughput
Investment
Std. Body Availability
GSM data
Circuit 9.6 kbits/s
Low
ETSI
Now
HSCSD
Circuit 56 kbits/s
Medium
ETSI
1999-2000
EDGE
Packet 380 kbits/s Medium
Ericsson 2000-2001
GPRS
Packet 150 kbits/s Medium
ETSI
UMTS
Packet
HSCSD
EDGE
GPRS
UMTS
N+I_2k
© 2000, Peter Tomsu
…
…
…
…
2 Mbits/s
High (radio) ETSI
2000-2001
2002
High Speed Circuit Switched Data
Enhanced Data Rate for GSM Evolution
General Packet Radio Service
Universal Mobile Telephone Service
01_mobile_wirel
11
GSM Packet Data Service Options
• Two services as part of "Phase 2+" of the GSM
specification
High Speed Circuit Switched Data
(HSCSD)
General Packet Radio Service
(GPRS)
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
12
High Speed Circuit Switched Data
(HSCSD)
• allows the combination of multiple timeslots
• Channels can be multiplexed together to offer a data rate of
up to 56 Kbit/s when using all four slots (14.4 Kbs/channel)
• because each time slot could carry a conventional
conversation, the use of multiple slots restricts the capacity
for speech traffic, resulting in the handset user specifying a
minimum acceptable data rate and a preferred (and usually
higher) data rate
• will prove particularly useful for applications with highspeed data requirements, such as large-scale file transfers,
advanced fax services and mobile video communications
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
13
General Packet Radio Service
(GPRS)
• available over GSM networks
• Data is packet switched - voice remains circuit switched
• may also be supported as part of other standards, such as DECT and
TDMA
• based on the transportation and routing of packetized data
• Capacity limitation is hence in terms of the amount of data being
transmitted rather than the time of connection
• reduces the time spent setting up and taking down connections
• works with public data networks using Internet protocol & X.25
• "bursty" applications such as e-mail, traffic telematics, telemetry,
broadcast services, and Web browsing
• requires modifications to the GSM system architecture and has
targeted commercial availability in the 1999 timeframe
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
14
HSCSD vs GPRS
• HSCSD is a small market
• HSCD doesn’t do anything to ease spectrum
capacity constraints that operators are facing
• GPRS benefits
ultimately, higher speed data
the packet data element is most important because
it uses the spectrum in a better way
not tying up a whole channel end-to-end for one
user
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
15
Enhanced Data Rate for GSM Evolution
(EDGE)
•GSM Standard bodies are defining data networking
technologies which will build upon GPRS
•One such technology is Enhanced Data Rate for GSM
Evolution (EDGE)
•EDGE will offer a theroretical rate of up to 384 Kbs.
•Beyond EDGE, 3G (UMTS) cellular systems will eventually
offer data rates up to 2 Mbs
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
16
Universal Mobile Telephone Service
UMTS
• 3G mobile system
• Developed within ITU-2000 framework
• Frequency bands
Terrestrial: 1885 – 2025 MHz and 2110 – 2200 MHz
Sattelite:
1980 – 2010 MHz and 2170 – 2200 MHz
• Data rates up to 2Mbps
• Inherent IP support
• Fully packet switched (data and voice)
• Concept of VME (Virtual Home Environment)
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
17
GSM Cellular Packet Data
SSS … Switching Subsystem
VLR … Visitor Location Register
HLR … Home Location Register
AUC … Authentication Center
EIR … Equipment Identity Center
MSC … Mobile Switching Center
BSS … Base Station Subsystem
BSC … Base Station Controller
BTS … Base Transceiver Stations
BTS
BSS
GPRS SGSN and
GGSN provide
packet data
services
VLR
SSS
HLR
AUC
Backhaul
EIR
Internet
BSC
MSC
BTS
MSC
BSC
N+I_2k
© 2000, Peter Tomsu
Transit
Net
01_mobile_wirel
GGSN
Transit
Net
SGSN
GSN … GPRS Support Node
SGSN … Serving GSN
GGSN … Gateway GSN
18
GSM Network Areas
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
19
GSM Network Areas
• GSM network consists of geographical areas
Location Areas – LA
made up of a group of cells served by a BSC
BSC hndles inter cell signaling updates
Keeps track of the cell a user is located
MSC/VLR Service Areas
MSC administers several BSCs
handles signaling traffic of inter LA updates
Public Land Mobile Networks – PLMNs
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
20
GPRS Logical Architecture
SMS-GMSC
SMS-IWMSC
SM-SC
E
C
Gd
MSC/VLR
HLR
D
Gs
A
Gr
Gb
TE
MT
R
BSS
Um
SGSN
Gn
SGSN
Gc
Gi
PDN
GGSN
Gn
Gp
TE
Gf
EIR
GGSN
Other PLMN
Signalling Interface
Signalling and Data Transfer Interface
• PS GPRS uses completely different network architecture as underlying
GSM network
• Thus introduction of two new network nodes GPRS Support Nodes
SGSN … Serving GSN (GPRS Support Node)
GGSN … Gateway GSN (GPRS Support Node)
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
21
SGSN and GGSN Functionality
SMS-GMSC
SMS-IWMSC
SM-SC
E
C
Gd
MSC/VLR
HLR
D
Gs
A
Gr
Gb
TE
MT
R
BSS
Um
SGSN
• SGSN
Gn
SGSN
Gc
Gi
PDN
GGSN
Gn
Gp
TE
Gf
EIR
GGSN
Other PLMN
Signalling Interface
Signalling and Data Transfer Interface
Keeps track of user’s location
Performs security functions and access control
• GGSN
Provides internetworking functions with
external networks
Simply a strong router with IP and X.25
capability
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
22
Further Elements and Enhancements
SMS-GMSC
SMS-IWMSC
SM-SC
E
C
Gd
MSC/VLR
HLR
D
Gs
A
Gr
Gb
TE
MT
R
BSS
Um
SGSN
Gn
SGSN
Gc
Gi
PDN
GGSN
Gn
Gp
TE
Gf
EIR
GGSN
Other PLMN
Signalling Interface
Signalling and Data Transfer Interface
• SGSNs are connected to PCUs (Packet Control Units which are
part of the BSC)
Via Gb interface – with FR links
• GSNs are interconnected over Gn interface via IP backbone
GPRS backbone or GPRS network
• HLR is enhanced with GPRS subscriber information
• SMS components are upgraded to support SMS transmission
via SGSN
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
23
Intra and Inter PLMN Backbone
Networks
• Gp interface
Packet Data Network
Inter-PLMN Backbone
Gi
Gp
GGSN
BG
Intra-PLMN Backbone
SGSN
SGSN
PLMN A
N+I_2k
© 2000, Peter Tomsu
Gi
BG
Connects two
independent GPRS
networks for message
exchange
GGSN
Intra-PLMN Backbone
Message exchange done
by BG (router)
• Gi interface
SGSN
PLMN B
Connection between
operator’s GPRS
networks and external
networks (Internet)
01_mobile_wirel
24
GPRS Support Nodes
• GSN is main element
in GPRS
infrastructure
Mobility router
Provides connection
Enables interworking
with various data
networks
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
25
GGSN
• Used to access external data network
• IP router containing all necessary
routing info for attached GPRS users
• Routing info used to tunnel PDUs to
MS’s current point of attachement
(SGSN)
• Allocation of dynamic IP addresses
Either itself or external DHCP server
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
26
SGSN
• Serves MS in terms of packet data
services
• SGSN establishes connection via GGSN to
requested data network
• Maintains all data structures (contexts) for
Authentication
Routing process
• In case of roaming (SGSN and GGSN in
different PLMNs) – interconnected via Gp
interface
N+I_2k
Provides security and others
© 2000, Peter Tomsu
01_mobile_wirel
27
PCU
• Located in the BSC
• Acts as an interface to the SGSN
• Distinguishes data and voice
• Sends data over FR via SGSN into GPRS
backbone
• Realized in SW or HW
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
28
APN
• Access Point Name
• Defined by ETSI in order to deal with huge
number of IP networks to connect to
• Uniquely identifies the network a user
wants to access
• L3 protocols defined are IPv4 and IPv6
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
29
APN
N+I_2k
Access Point
Name (username)
Type (Ipv4, Ipv6,
X.25)
Access mode
(non/transparent)
DHCP local pool
information
Accept network
initiate PDP
create request
List of PDP
contexts on the
APN
IP for DHCP,
RADIUS …
IP for charging
gateway
© 2000, Peter Tomsu
• Contains
Name of foreign NW
Network access mode
• Stored in HLR
• User may select APN
by himself from the
MS
01_mobile_wirel
30
GPRS Concepts
• APN: targeted network (ISP, intranet)
• PDP context: session id
• 1) reach the SGSN (telecom part)
• 2) reach the GGSN serving the APN
(GTP=moving tunnel)
• 3) reach the APN (dedicated link, tunnel)
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
31
GPRS PDN Interworking Model
GGSN
IP
GPRS Bearer
Gi
IP
L2
L1
• GGSN is access point for internetworking
Seen from outside as normal router
GPRS network seems to be normal IP subnet
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
32
GPRS Transmission Plane
Application
IP / X.25
IP / X.25
Relay
SNDCP
SNDCP
GTP
GTP
LLC
LLC
UDP /
TCP
UDP /
TCP
IP
IP
Relay
RLC
RLC
BSSGP
BSSGP
MAC
MAC
Network
Service
Network
Service
L2
L2
GSM RF
GSM RF
L1bis
L1bis
L1
L1
MS
Um
BSS
Um … radio interface
Uses same PL coding as classical GSM
Thus no HW changes
TE requires up to 8 slots / TDMA frame
N+I_2k
© 2000, Peter Tomsu
Gb
SGSN
Gn
GGSN
Gi
GTP … GPRS Tunneling Protocol
SNDCP … Subnetwork Dependent
Convergence Protocol
BSSGP … Base Station System
GPRS Protocol
01_mobile_wirel
33
Gb Interface
Application
IP / X.25
IP / X.25
Relay
SNDCP
LLC
SNDCP
GTP
GTP
LLC
UDP /
TCP
UDP /
TCP
IP
IP
L2
Relay
RLC
RLC
BSSGP
BSSGP
MAC
MAC
Network
Service
Network
Service
L2
GSM RF
L1bis
L1bis
L1
GSM RF
MS
Um
BSS
Gb
SGSN
L1
Gn
GGSN
Gi
• Link layer is FR
• BSSGP (BSS GPRS) conveys routing and QoS
info between BSS and SGSN
• SNDCP encapsulates IP traffic between terminal
and SGSN
Multiplexing of L3 connections
Ciphering, segmentation, compression
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
34
Gn Interface
Application
IP / X.25
IP / X.25
Relay
SNDCP
LLC
SNDCP
GTP
GTP
LLC
UDP /
TCP
UDP /
TCP
IP
IP
L2
Relay
RLC
RLC
BSSGP
BSSGP
MAC
MAC
Network
Service
Network
Service
L2
GSM RF
L1bis
L1bis
L1
GSM RF
MS
Um
BSS
Gb
SGSN
L1
Gn
GGSN
Gi
• GTP (ETSI) tunnels IP packets between
SGSN and GGSN
One tunnel per active TE
• Runs either over UDP or TCP
Port #3386
IP
N+I_2k
© 2000, Peter Tomsu
UDP
GTP
DATA
01_mobile_wirel
35
MS
R reference point
TE
MT
Um
Gi reference point
GPRS network 1
MS
PDNs or
other networks
Gp
GPRS network 2
• MS could be
Only GPRS phone
User with NW connection via GPRS to
his PC
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
36
Transparent Internet Access
The GGSN is effectively a router
The GPRS network appears to the PDN as another IP subnet
• User who wants to get connected to internet
• MS is given an IP address out of the operators address space
Could be statically or dynamically allocated
May be public or private
• Authentication performed by SGSN via HLR
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
37
Transparent Internet Access
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
38
Non Transparent Access
• Allows user to select SPs of his choice
• Connection to intranet VPN for email access, intraweb, databases
• Has to request IP address and perform authentication in company network
• Realized by SGSN during PDP context activation via selected APN
• MS sends authentication request
• GGSN requests authentication and IP address from specified server (Radius,
DHCP) of customers intranet
• Use of Ipsec and/or L2 tunnel for terminating private IP addresses at GGSN via
Internet
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
39
Interworking Between GPRS
Roaming User’s
BGP (RFC 1771)
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
40
QoS on GPRS
BTS
BSC
H.323
client
FR
FR CoS
SGSN
IP QoS
Priotities CAR
IP QoS
WFQ
CRTP
CRTP
N+I_2k
© 2000, Peter Tomsu
Transit
Net
GGSN
IP QoS
IP
H.323
GW
PSTN
H.323
Gateway
WFQ
WRED
01_mobile_wirel
IP QoS
41
Quality of Service
Mapping between GPRS QoS and IP QoS levels
Delay Class
Precedence
Mean-Throughput Resulting “canonical” QoS
Class
Best Effort
any
any
Best Effort
1, 2, 3
low
any
Best Effort
1,2, 3
any
Best Effort
Best Effort
1,2, 3
normal
specified
Normal
1,2,3
high
specified
Premium
• Use of IP CoS mechanisms in GGSN/SGSN and in the Backbone:
WRED, WFQ, CAR
• Admission Control (GGSN): S traffic < Total BW
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
42
Backbone Issues
• Leverage End-to-End Consistency
• WFQ, WRED, CAR
• MPLS (GGSN as edge router)
• Integrated management
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
43
IP Address Management
• GGSN can hold (local pool/DHCP):
– Operator’s public IP addresses
– Operator’s private IP addresses (NAT)
– Other’s public IP addresses (local pool)
– Other’s private IP addresses (local pool,
dedicated I/F)
• configuration per APN
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
44
IP Address Management
• GGSN can allocate addresses:
– transparently (local pool using built-in DHCP
server/DHCP)
– non-transparently (CHAP/IPCP processing,
RADIUS/DHCP requests generation) through IOS
built-in RADIUS/DHCP clients
• configuration per APN
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
45
GSM to UMTS Evolution
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
46
Evolution Towards
UMTS
• UMTS Backward compatibility to legacy systems
• Operators will try to use existing infrastructure as long as possible
• Development steps
1) MIP on top of GPRS
2) optimize existing routing mechanisms
3) SGSN and GGSN combined in one node
• In future UMTS will completely integrate PSTN
VSCs will replace all class 4 and class 5 switches
Calls will be routed over IP backbone
N+I_2k
© 2000, Peter Tomsu
01_mobile_wirel
47
Questions ???