cisco presentation guide
TRANSCRIPT
MobileWirelessMobile
Wireless
2N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Exponential Growth of World Wide GSM Data Users
Exponential Growth of World Wide GSM Data Users
Growth in mobile data is expected to be 70% p.a. in next 5 yrs (Merryl Lynch)
0102030405060708090
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
in m
illion
su
bscri
ber
early adaptors early majority Late majorityinnovators
~ 1%
3N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Dramatic Increase of Mobile Data Volume
Dramatic Increase of Mobile Data Volume
0
5
10
15
20
25
30
35
1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005
Mb
yte
s p
er
user
per
mon
th
UMTS study funded by the European Comission 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
Today0.8 Mb/user/month
4N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Wireless Data Network DriversWireless Data Network Drivers
• Information access
• PDAs
• Network computers
• Alpha paging, information distribution
• Web/WAP technology
5N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
DataApplications
Call Forwarding 37%
Paging 33%
Internet/E-mail 24%
Traffic/Weather 15%
Conference Calling 13%
News 3%
Call Forwarding 37%
Paging 33%
Internet/E-mail 24%
Traffic/Weather 15%
Conference Calling 13%
News 3%
Services Most Often RequestedServices Most Often Requested
Source: CTIA Web PagePeter D. Hart Research Associates, March 1997
After Basic Wireless Telephony Service
6N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Data Services on CellularData Services on Cellular
• Standards for packet services on cellular are already defined
GSM: GPRS - GSM Packet Radio SystemGSM: GPRS - GSM Packet Radio System
CDMA: IWF and MobileIPCDMA: 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
7N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Wireless Market SegmentsWireless Market Segments
Wireless Market Segments & Partners
Fixed Mobile
Broadband Multiservice2G+
Cellular3G
Cellular
Residential/Premise/ Campus
LMDSMMDS
Cisco/Bosch
DataServices
GPRSMobile IP
PacketData/Voice
UMTS
8N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Residential WLANsResidential WLANs
• Found in office environment for wireless network access
• Either infrared or radio
• Standards are
Bluetooth
IEEE 802.11
9N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Fixed WirelessFixed 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
10N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Mobile Wireless NetworksMobile 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
11N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GPRS and other Mobile Wireless Technologies
GPRS and other Mobile Wireless Technologies
GSM dataGSM data Circuit 9.6 kbits/sCircuit 9.6 kbits/s LowLow ETSIETSI Now Now
HSCSDHSCSD Circuit 56 kbits/sCircuit 56 kbits/s MediumMedium ETSIETSI 19991999--20002000
EDGEEDGE Packet 380 kbits/sPacket 380 kbits/s MediumMedium Ericsson Ericsson 2000-20012000-2001
GPRSGPRS Packet 150 kbits/sPacket 150 kbits/s MediumMedium ETSIETSI 2000-20012000-2001
UMTSUMTS Packet 2 Mbits/sPacket 2 Mbits/s High (radio)High (radio) ETSIETSI 20022002
HSCSDHSCSD …… High Speed Circuit Switched DataHigh Speed Circuit Switched DataEDGE EDGE … … Enhanced Data Rate for GSM EvolutionEnhanced Data Rate for GSM EvolutionGPRS GPRS … … General Packet Radio ServiceGeneral Packet Radio ServiceUMTS UMTS … … Universal Mobile Telephone ServiceUniversal Mobile Telephone Service
Technology Type Throughput Investment Std. Body AvailabilityTechnology Type Throughput Investment Std. Body Availability
12N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GSM Packet Data Service OptionsGSM Packet Data Service Options
• Two services as part of "Phase 2+" of the GSM specification
High Speed Circuit Switched Data High Speed Circuit Switched Data
(HSCSD) (HSCSD)
General Packet Radio ServiceGeneral Packet Radio Service
(GPRS)(GPRS)
13N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
High Speed Circuit Switched Data (HSCSD)
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 high-speed data requirements, such as large-scale file transfers, advanced fax services and mobile video communications
14N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
General Packet Radio Service (GPRS)
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
15N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
HSCSD vs GPRSHSCSD 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
16N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Enhanced Data Rate for GSM Evolution (EDGE)
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
17N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Universal Mobile Telephone Service UMTS
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)
18N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GSM Cellular Packet DataGSM Cellular Packet Data
BSCBSC
BSCBSC
MSCMSC
MSCMSC
EIREIR
AUCAUC
HLRHLR
VLRVLRGPRS SGSN and
GGSN provide packet data services
BTS
BTS
Backhaul
Internet
SGSNSGSN
GGSNGGSN
TransitNet
TransitNet
SSS
SSS … Switching SubsystemVLR … Visitor Location RegisterHLR … Home Location RegisterAUC … Authentication CenterEIR … Equipment Identity CenterMSC … Mobile Switching Center
BSS
BSS … Base Station SubsystemBSC … Base Station ControllerBTS … Base Transceiver Stations
GSN … GPRS Support NodeSGSN … Serving GSNGGSN … Gateway GSN
19N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GSM Network AreasGSM Network Areas
BSCBSC
BS
BS
BS
MSC
HLR
EIR
VLR
Switching Subsystem
MSC Service Area
Location Area
Cell
AUC
Base StationSubsystem
Service Area 1
Service Area 2
Service Area n
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
20N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GSM Network AreasGSM 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
BSCBSC
BS
BS
BS
MSC
HLR
EIR
VLR
Switching Subsystem
MSC Service Area
Location Area
Cell
AUC
Base StationSubsystem
Service Area 1
Service Area 2
Service Area n
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
21N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GPRS Logical ArchitectureGPRS Logical Architecture
• 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)
Gf
D
Gi
Gn
Gb
Gc
CE
Gp
Gs
Signalling and Data Transfer Interface
Signalling Interface
MSC/VLR
TE MT BSS TEPDN
R Um
GrA
HLR
Other PLMN
SGSN
GGSN
Gd
SM-SCSMS-GMSC
SMS-IWMSC
GGSN
EIR
SGSN
Gn
22N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
SGSN and GGSN FunctionalitySGSN and GGSN Functionality
• SGSN
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
Gf
D
Gi
Gn
Gb
Gc
CE
Gp
Gs
Signalling and Data Transfer Interface
Signalling Interface
MSC/VLR
TE MT BSS TEPDN
R Um
GrA
HLR
Other PLMN
SGSN
GGSN
Gd
SM-SCSMS-GMSC
SMS-IWMSC
GGSN
EIR
SGSN
GnGf
D
Gi
Gn
Gb
Gc
CE
Gp
Gs
Signalling and Data Transfer Interface
Signalling Interface
MSC/VLR
TE MT BSS TEPDN
R Um
GrA
HLR
Other PLMN
SGSN
GGSN
Gd
SM-SCSMS-GMSC
SMS-IWMSC
GGSN
EIR
SGSN
Gn
23N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Further Elements and EnhancementsFurther Elements and Enhancements
• 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
Gf
D
Gi
Gn
Gb
Gc
CE
Gp
Gs
Signalling and Data Transfer Interface
Signalling Interface
MSC/VLR
TE MT BSS TEPDN
R Um
GrA
HLR
Other PLMN
SGSN
GGSN
Gd
SM-SCSMS-GMSC
SMS-IWMSC
GGSN
EIR
SGSN
GnGf
D
Gi
Gn
Gb
Gc
CE
Gp
Gs
Signalling and Data Transfer Interface
Signalling Interface
MSC/VLR
TE MT BSS TEPDN
R Um
GrA
HLR
Other PLMN
SGSN
GGSN
Gd
SM-SCSMS-GMSC
SMS-IWMSC
GGSN
EIR
SGSN
Gn
24N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Intra and Inter PLMN Backbone Networks
Intra and Inter PLMN Backbone Networks
• Gp interface
Connects two independent GPRS networks for message exchange
Message exchange done by BG (router)
• Gi interface
Connection between operator’s GPRS networks and external networks (Internet)
BG
SGSN
BG
SGSN
GGSN GGSN
SGSN
Intra-PLMN BackboneIntra-PLMN Backbone
Gi Gp Gi
PLMN A PLMN B
Packet Data Network
Inter-PLMN Backbone
25N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GPRS Support NodesGPRS Support Nodes
• GSN is main element in GPRS infrastructure
Mobility router
Provides connection
Enables interworking with various data networks
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
BSCBSC
BS
BS
BS
SGSN
SGSN
GGSN
GGSN
Internet
IntranetISP
SGSN
IP Backbone
26N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GGSNGGSN
• 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
27N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
SGSNSGSN
• 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
Provides security and others
28N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
PCUPCU
• 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
29N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
APN 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
30N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
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
APNAPN
• Contains
Name of foreign NW
Network access mode
• Stored in HLR
• User may select APN by himself from the MS
31N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GPRS ConceptsGPRS 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)
32N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GPRS PDN Interworking ModelGPRS PDN Interworking Model
• GGSN is access point for internetworking
Seen from outside as normal router
GPRS network seems to be normal IP subnet
Gi
IP
GGSN
GPRS Bearer
IP
L2
L1
33N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GPRS Transmission PlaneGPRS Transmission Plane
Relay
NetworkService
GTP
Application
IP / X.25
SNDCP
LLC
RLC
MAC
GSM RF
SNDCP
LLC
BSSGP
L1bis
RLC
MAC
GSM RF
BSSGP
L1bis
Relay
L2
L1
IP
L2
L1
IP
GTP
IP / X.25
Um Gb Gn GiMS BSS SGSN GGSN
NetworkService
UDP /TCP
UDP /TCP
Um … radio interfaceUses same PL coding as classical GSMThus no HW changesTE requires up to 8 slots / TDMA frame
GTP … GPRS Tunneling ProtocolSNDCP … Subnetwork Dependent
Convergence ProtocolBSSGP … Base Station System
GPRS Protocol
34N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Gb InterfaceGb Interface
• 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
Relay
NetworkService
GTP
Application
IP / X.25
SNDCP
LLC
RLC
MAC
GSM RF
SNDCP
LLC
BSSGP
L1bis
RLC
MAC
GSM RF
BSSGP
L1bis
Relay
L2
L1
IP
L2
L1
IP
GTP
IP / X.25
Um Gb Gn GiMS BSS SGSN GGSN
NetworkService
UDP /TCP
UDP /TCP
Relay
NetworkService
GTP
Application
IP / X.25
SNDCP
LLC
RLC
MAC
GSM RF
SNDCP
LLC
BSSGP
L1bis
RLC
MAC
GSM RF
BSSGP
L1bis
Relay
L2
L1
IP
L2
L1
IP
GTP
IP / X.25
Um Gb Gn GiMS BSS SGSN GGSN
NetworkService
UDP /TCP
UDP /TCP
35N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Gn InterfaceGn Interface
• GTP (ETSI) tunnels IP packets between SGSN and GGSN
One tunnel per active TE
• Runs either over UDP or TCP
Relay
NetworkService
GTP
Application
IP / X.25
SNDCP
LLC
RLC
MAC
GSM RF
SNDCP
LLC
BSSGP
L1bis
RLC
MAC
GSM RF
BSSGP
L1bis
Relay
L2
L1
IP
L2
L1
IP
GTP
IP / X.25
Um Gb Gn GiMS BSS SGSN GGSN
NetworkService
UDP /TCP
UDP /TCP
Relay
NetworkService
GTP
Application
IP / X.25
SNDCP
LLC
RLC
MAC
GSM RF
SNDCP
LLC
BSSGP
L1bis
RLC
MAC
GSM RF
BSSGP
L1bis
Relay
L2
L1
IP
L2
L1
IP
GTP
IP / X.25
Um Gb Gn GiMS BSS SGSN GGSN
NetworkService
UDP /TCP
UDP /TCP
DATAUDP GTPIP
Port #3386
36N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
MSMS
• MS could be
Only GPRS phone
User with NW connection via GPRS to his PC
Gi reference point
GPRS network 1
GPRS network 2
PDNs orother networksTE MT
Gp
UmR reference point
MS
37N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Transparent Internet AccessTransparent Internet Access
• 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
The GGSN is effectively a router
The GPRS network appears to the PDN as another IP subnet
38N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Transparent Internet AccessTransparent Internet Access
39N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Non Transparent AccessNon 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
L2TP & IPsec TunnelGPRS IP
Backbone
Firewalland NAT
GSM
Internet
Firewalland NAT
Corporate VPN
SGSN
GGSN
40N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Interworking Between GPRS Roaming User’s
Interworking Between GPRS Roaming User’s
BGP (RFC 1771)
41N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
QoS on GPRSQoS on GPRS
BSCBSC SGSNSGSN GGSNGGSNFRFR TransitTransitNetNet
IPIPBTSBTS PSTNPSTNH.323H.323GWGW
H.323 client
IP QoS
CRTP
FR CoS
Priotities
IP QoS
CAR
WFQ
CRTP
IP QoS
WFQ
WREDIP QoS
H.323 Gateway
42N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Quality of ServiceQuality of Service
Mapping between GPRS QoS and IP QoS levelsMapping between GPRS QoS and IP QoS levels
Delay Class Precedence Mean-Throughput Resulting “canonical” QoSClass
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): traffic Total BW
43N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Backbone IssuesBackbone Issues
• Leverage End-to-End Consistency
• WFQ, WRED, CAR
• MPLS (GGSN as edge router)
• Integrated management
44N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
IP Address ManagementIP 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
45N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
IP Address ManagementIP 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
46N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
GSM to UMTS EvolutionGSM to UMTS Evolution
47N+I_2k © 2000, Peter Tomsu 01_mobile_wirel
Evolution TowardsUMTS
Evolution TowardsUMTS
• 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
Questions ???Questions ???