Mobile Wireless Technology

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 (Merryl Lynch)

90 80 70 60 50 40 30 20 10 0

innovators

early adaptors

early majority

Late majority

~ 1%

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005

N+I_2k

© 2000, Peter Tomsu

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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

N+I_2k

35 30 25 20 15 10

Today 0.8 Mb/user/month

5 0 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 © 2000, Peter Tomsu

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Wireless Data Network Drivers

• Information access • PDAs • Network computers • Alpha paging, information distribution • Web/WAP technology

N+I_2k

© 2000, Peter Tomsu

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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

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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

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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

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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

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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

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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

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GPRS and other Mobile Wireless Technologies

chnology

Type

Throughput

Investment

Std. Body

GSM data

Circuit 9.6 kbits/s

Low ETSI

HSCSD 2000

Circuit 56 kbits/s

Medium

Now ETSI

EDGE Packet 380 kbits/s

Medium

Ericsson

GPRS Packet 150 kbits/s

Medium

ETSI

UMTS Packet

High (radio)

2 Mbits/s

HSCSD EDGE GPRS UMTS N+I_2k

© 2000, Peter Tomsu

… … … …

Availability

1999 2000-2001

2000-2001 ETSI

2002

High Speed Circuit Switched Data Enhanced Data Rate for GSM Evolution General Packet Radio Service Universal Mobile Telephone Service 01_mobile_wirel

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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

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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

N+I_2k

© 2000, Peter Tomsu

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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

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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

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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

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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

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GSM Cellular Packet Data BSS … Base Station Subsystem BSC … Base Station Controller BTS … Base Transceiver Stations BTS

BSS

Backhaul

SSS … Switching Subsystem VLR … Visitor Location Register HLR … Home Location Register AUC … Authentication Center EIR … Equipment Identity Center MSC … Mobile Switching Center GPRS SGSN and VLR GGSN provide packet data SSS HLR services AUC EIR

BSC

MSC BTS

MSC BSC

N+I_2k

© 2000, Peter Tomsu

Transit Net

01_mobile_wirel

Internet GGSN

Transit Net SGSN GSN … GPRS Support Node SGSN … Serving GSN GGSN … Gateway GSN 18

GSM Network Areas B a s e S ta tio n S u b s y s te m BS

BS

BSC

BSC

BS BS

BSC

AUC

HLR

BS BSC

E IR BS

BS

BSC

VLR

BS

M SC

BSC

S w itc h in g S u b s y s t e m

BS BS

BSC

BS BSC

M S C S e r v ic e A re a BS

L o c a tio n A r e a BS

BSC

BS BSC

C e ll

BS

S e r v ic e A re a 1 S e r v ic e A r e a 2 S e r v ic e A re a n

N+I_2k

© 2000, Peter Tomsu

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B a s e S t a ti o n S u b s y s te m BS

GSM Network Areas

BS

BSC

BSC

BS BS

HLR

BS

BSC

AUC

BS C

E IR BS

BS

BSC

VLR

BS

M SC

B SC

S w it c h in g S u b s y s t e m

BS BS

BSC

BS BSC

M S C S e r v ic e A r e a BS

L o c a t io n A r e a BS

BSC

BS BSC

C e ll

BS

S e rv ic e A re a 1 S e r v ic e A r e a 2 S e r v ic e A r e a n

• 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

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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

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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

Gn

SGSN

Gc Gi PDN

GGSN Gn

Gp

TE

Gf EIR

GGSN Other PLMN

Signalling Interface Signalling and Data Transfer Interface

• 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 N+I_2k

© 2000, Peter Tomsu

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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

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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

GGSN

Intra-PLMN Backbone

Connects two independent GPRS networks for message exchange Message exchange done by BG (router)

• Gi interface

SGSN PLMN B

Connection between operator’s GPRS networks and external networks (Internet) 01_mobile_wirel

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GPRS Support Nodes

BS

BSC

BS BSC

BS B S

BSC

BS BSC

BS

BS

Mobility router

GGSN SGSN

BS

BSC

In te r n e t

SGSN

• GSN is main element in GPRS infrastructure

B SC

BS

Provides connection

IP B a c k b o n e B S

BSC

BS

SGSN

BSC

GGSN

In tr a n e t IS P

BS BS

BSC

BS BSC

B S

N+I_2k

© 2000, Peter Tomsu

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Enables interworking with various data networks

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

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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 Provides security and others

N+I_2k

© 2000, Peter Tomsu

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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

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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

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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

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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

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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

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GPRS Transmission Plane Application IP / X.25

IP / X.25 Relay

SNDCP

SNDCP

GTP

GTP

LLC

LLC

UDP / TCP

UDP / TCP

IP

IP

L2

L2

L1

L1

Relay

RLC

RLC

MAC

MAC

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

BSSGP

Network Service GSM RF L1bis

GSM RF

MS

BSSGP

© 2000, Peter Tomsu

Network Service L1bis Gb

SGSN

Gn

GGSN

Gi

GTP … GPRS Tunneling Protocol SNDCP … Subnetwork Dependent Convergence Protocol BSSGP … Base Station System GPRS Protocol 01_mobile_wirel

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Gb Interface

Application IP / X.25

IP / X.25 Relay

SNDCP LLC

SNDCP

GTP

GTP

LLC

UDP / TCP

UDP / TCP

IP

IP

L2

L2

L1

L1

Relay

RLC

RLC

MAC

MAC

BSSGP

Network Service GSM RF L1bis

GSM RF

MS

BSSGP

Um

BSS

Network Service L1bis Gb

SGSN

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

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Gn Interface

Application IP / X.25

IP / X.25 Relay

SNDCP LLC

SNDCP

GTP

GTP

LLC

UDP / TCP

UDP / TCP

IP

IP

L2

L2

L1

L1

Relay

RLC

RLC

MAC

MAC

BSSGP

Network Service GSM RF L1bis

GSM RF

MS

BSSGP

Um

BSS

Network Service L1bis Gb

SGSN

Gn

GGSN

Gi

• GTP (ETSI) tunnels IP packets between SGSN and GGSN One tunnel per active TE • Runs either over UDP or TCP P o rt # 3 3 8 6 IP

N+I_2k

© 2000, Peter Tomsu

UDP

GTP

DATA

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MS R reference point TE

Um

MT

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

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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

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Transparent Internet Access

N+I_2k

© 2000, Peter Tomsu

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Non Transparent Access C o rp o ra te VPN

G G SN G P R S IP B ackbone

G SM

In t e r n e t L 2 T P & IP s e c T u n n e l

SG SN F ir e w a ll and N AT

F ir e w a ll and NAT

• 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

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Interworking Between GPRS Roaming User’s

BGP (RFC 1771)

N+I_2k

© 2000, Peter Tomsu

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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 WFQ WRED

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IP

H.323 GW

PSTN

H.323 Gateway IP QoS

41

Quality of Service Mapping between GPRS QoS and IP QoS levels D e la y C la s s P re c e d e n c eM e a n -T h ro u g h Rp ue ts u ltin g “c a n o n ic a l” Q o S C la s s B e s t E ffo rt a n y

any

B e s t E ffo rt

1, 2, 3

lo w

any

B e s t E ffo rt

1 ,2 , 3

any

B e s t E ffo rt

B e s t E ffo rt

1 ,2 , 3

n o rm a l

s p e c ifie d

N o rm a l

1 ,2 ,3

h ig h

s p e c ifie d

P re m iu m

• Use of IP CoS mechanisms in GGSN/SGSN and in the Backbone: WRED, WFQ, CAR • Admission Control (GGSN): Σ traffic < Total BW N+I_2k

© 2000, Peter Tomsu

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Backbone Issues

• Leverage End-to-End Consistency • WFQ, WRED, CAR • MPLS (GGSN as edge router) • Integrated management

N+I_2k

© 2000, Peter Tomsu

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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

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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

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GSM to UMTS Evolution

N+I_2k

© 2000, Peter Tomsu

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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

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Questions ???