© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-102
Cellular Mobile TelephonyEssential inventions/criteria's
� Frequency modulation
� Antenna diversity
� Cellular concept
– Bell Labs (1957 & 1960)
� Frequency reuse
– Typically every 7 cells
� Handoff as caller moves
� Modified CO (Central Office) switch, e.g. AXE
– HLR, paging, handoffs
� Sectors improve reuse
– Every 3 cells possible
1
2
3
4
5
6
7
1
2
3
4
5
6
7
572
2
11
2
3
4
5
6
7
3
1
2
2
3
1
1
2
2
3
3
1
2
2
3
311
3
13
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-103
NMT1G – Frequency Division Multiple Access
� Nordic Mobile Telephony (NMT)
� Deployed in Sweden, Norway, Demark & Finland
� Launched 1981; now largely retired
� Spectrum: 450 MHz; later at 900 MHz (NMT900)
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-104
GSM2G – Time Division Multiple Access
� « Groupe Special Mobile », later changed to « Global System for Mobile »
– Joint European effort beginning in 1982
– Focus on seamless roaming across Europe
� Services launched 1991– Time division multiple access (8 users per 200KHz)
– 900 MHz band; later extended by 1800MHz (WW non US)
– Added 1900 MHz (US PCS bands)
� GSM is dominant world standard today– Well defined interfaces; many competitors
– Network effect (Metcalfe’s law) took hold in late 1990s
– Tri-band GSM phone can roam the world today
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-105
W-CDMA (UMTS)3G – Code Division Multiple Access
� Wideband CDMA– Standard for Universal Mobile Telephone Service (UMTS)
� Committed standard for Europe and likely migration path for other GSM operators
– Leverages GSM’s dominant position
� Requires substantial new spectrum– 5 MHz each way (symmetric)
� Legally mandated in Europe and elsewhere
� Sales of new spectrum completed in Europe– At prices that now seem exorbitant
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-106
LTE4G
� Aim to 100 Mbps (moving) & 1 Gbps (stationary)
� Seamless roaming across heterogeneous networks
� Sophisticated multiple access schemes– DL: OFDMA with Cyclic Prefix (CP)
– UL: Single Carrier FDMA (SC-FDMA) with CP
� Adaptive modulation and coding– QPSK, 16QAM, and 64QAM
– 1/3 coding rate, two 8-state constituent encoders
� Advanced MIMO spatial multiplexing techniques– (2 or 4) x (2 or 4) downlink and uplink
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-107
GSM/WCDMA coverage map
GSM Coverage
Source: Chart: GSM Association January 2007WCDMA Coverage
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-108
Migration To 3G and beyond
CDMA
GSM
TDMA
PHS (IP-Based)
64 Kbps
GPRS
115 Kbps
CDMA 1xRTT
144 Kbps
EDGE
384 Kbps
cdma2000
1X-EV-DV
Over 2.4 Mbps
W-CDMA
(UMTS)
Up to 2 Mbps
2G2.5G
2.75G 3G
1992 - 2000+2001+
2003+
1G
1984 - 1996+
2003 - 2004+
TACS
NMT
AMPS
GSM/
GPRS
(Overlay) 115 Kbps
9.6 Kbps
9.6 Kbps
14.4 Kbps/ 64 Kbps
9.6 Kbps
PDC
Analog Voice
Digital Voice
Packet Data
IntermediateMultimedia
Multimedia
PHS
TD-SCDMA
2 Mbps?
9.6 Kbps
iDEN
(Overlay)
iDEN
Source: U.S. Bancorp Piper Jaffray
3.5G (4G?)All IP
LTELTE
Up to 100 Mbps,eventually
UMBUMB
2007+ - 2010+
UMB - Ultra Mobile Broadband
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-109
Technology trends
� Faster networks
� More powerful processors
� Higher memory capacity
Leverage commercial evolution
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1010
CDMA
Growth in mobile subscriptionsWireless subscriptions worldwide
0
1000
2000
3000
4000
5000
6000
2005 2006 2007 2008 2009 2010 2011 2012
Re
po
rte
d S
ub
sc
rip
tio
ns
(M
illi
on
s)
3G and LTE
GSM/EDGE
Mobile WiMAX (yellow)
2006
2005
2004
3GPP family
Main growth in the 3GPP technology
Other technologies (gray)
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1011
Mobil Broadband Evolution
28 Mbps 160 Mbps
Leading Mobile Broadband Capabilities, now and in the future ..
1 000
100
10
1
0,1
2004 2005 2006 2007 2008 2009 2010
Mbps
Downlink
Uplink
Turbo 3G (HSPA)
HSPA Evolved 3G LTE
3.6 Mbps
EDGE
472 kbps
EDGE evolution
1 Mbps
Turbo 3G (HSPA)
14,4 Mbps
3G
2GDownlink
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1012
StandardizationGSM standardization
� 1982 -- European Conference of Postal and Telecommunications Administrations (CEPT)
– Create “Groupe Spécial Mobile” (GSM), a standard for a mobile telephone system intended to be used across Europe
� 1987 -- A memorandum of understanding was signed by 13 countries to develop a common cellular telephone system across Europe
� 1988 -- European Telecommunications Standards Institute (ETSI)– Created by CEPT
– GSM responsibility transferred to ETSI
� 1990 -- Phase I of the GSM specifications published.
� 1991 -- First GSM network was launched
� 1993 -- Over a million subscribers using GSM– 70 carriers across 48 countries
� 1998 – 3GPP formed
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1013
3G Partnership ProjectDefining migration from GSM to UMTS (W-CDMA)
� ETSI, Association of Radio Industries and Businesses/Telecommunication Technology Committee (ARIB/TTC) (Japan), China Communications Standards Association, Alliance for Telecommunications Industry Solutions (North America) and Telecommunications Technology Association (South Korea)
� 3GPP Release 99 (2000)– Specified the first UMTS 3G networks, incorporating a CDMA air interface
� 3GPP Release 4 (2001)– Adds softswitch/ voice gateways, packet core and all-IP Core Network
� 3GPP Release 5 (2002)– First IP Multimedia Services (IMS) w/ SIP & QoS and HSDPA
� 3GPP Release 6 (2004)– “All IP” network and adds HSUPA and MBMS (core of MobileTV)
� 3GPP Release 7 (2007)– Decreasing latency, improvements to QoS, HSPA+ (High Speed Packet
Access Evolution) and EDGE Evolution
� 3GPP Release 8 (2009)– LTE, All-IP Network (SAE) (System Architecture Evolution)
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1014
ArchitectureTypical 2G
BTS — Base Transceiver Station
BSC — Base Station Controller
MSC — Mobile Switching Center
VLR — Visitor Location Register
HLR — Home Location Register
BTS
BSC
MSC/VLR
HLRBSC
GMSC
CO
BSC
BSCMSC/VLR
CO
PSTN
PLMN
CO
Tandem Tandem
SMS-SC
PSDN
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1015
ArchitectureGSM 2G
BSS — Base Station System
BTS — Base Transceiver Station
BSC — Base Station Controller
MS — Mobile Station
NSS — Network Sub-System
MSC — Mobile-service Switching Controller
VLR — Visitor Location Register
HLR — Home Location Register
AuC — Authentication Server
GMSC — Gateway MSC
SS7BTS
BSCMSC
VLR
HLRAuC
GMSC
BSS
PSTN
NSS
A
E
C
D
PSTNAbis
B
H
MS
GSM — Global System for Mobile communication
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1016
GPRS — 2.5G for GSM
� General Packet Radio Service– First introduction of packet technology
� Aggregate radio channels– Support higher data rates (115 kbps, 8 TS x 14.4 kbps)
– Subject to channel availability/resource allocation
� Share aggregate channels among multiple users
� All new IP-based data infrastructure
� No changes to voice network
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1017
ArchitectureGSM 2.5G
SS7BTS
BSCMSC
VLR
HLRAuC
GMSC
BSS
PSTN
NSS
A
E
C
D
PSTNAbis
B
H
MS
BSS — Base Station System
BTS — Base Transceiver Station
BSC — Base Station Controller
NSS — Network Sub-System
MSC — Mobile-service Switching Controller
VLR — Visitor Location Register
HLR — Home Location Register
AuC — Authentication Server
GMSC — Gateway MSC
SGSN — Serving GPRS Support Node
GGSN — Gateway GPRS Support Node
GPRS — General Packet Radio Service
IP
2G+ MS (voice & data)
PSDNGi
SGSN
Gr
Gb
Gs
GGSN
Gc
Gn
2G MS (voice only)
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1018
EDGEEnhanced Data rates for Global Evolution
� Increased data rates with GSM compatibility– Still 200 KHz bands; still TDMA
– 8-PSK modulation: 3 bits/symbol give 3X data rate
– 9 MCS (Modulation Coding Schemes), 8.8 – 59.2 kpbs/TS
– Shorter range (more sensitive to noise/interference)
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1019
3G rel99 Architecture (UMTS)3G Radios
SS7
IP
BTS
BSCMSC
VLR
HLRAuC
GMSC
BSS
SGSN GGSN
PSTN
PSDN
CN
CD
GcGr
Gn Gi
Abis
Gs
B
H
BSS — Base Station System
BTS — Base Transceiver Station
BSC — Base Station Controller
RNS — Radio Network System
RNC — Radio Network Controller
CN — Core Network
MSC — Mobile-service Switching Controller
VLR — Visitor Location Register
HLR — Home Location Register
AuC — Authentication Server
GMSC — Gateway MSC
SGSN — Serving GPRS Support Node
GGSN — Gateway GPRS Support Node
AE PSTN
2G MS (voice only)
2G+ MS (voice & data)
UMTS — Universal Mobile Telecommunication System
Gb
3G UE (voice & data)
Node B
RNC
RNS
Iub
IuCS
ATM
IuPS
Major advantage:
Shared Core NW
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1020
3G rel4 Architecture (UMTS)Soft Switching
SS7
IP/ATM
BTS
BSCMSC Server
VLR
HLRAuC
GMSC server
BSS
SGSN GGSN
PSTN
PSDN
CN
CD
GcGr
Gn Gi
Gb
Abis
Gs
B
H
BSS — Base Station System
BTS — Base Transceiver Station
BSC — Base Station Controller
RNS — Radio Network System
RNC — Radio Network Controller
CN — Core Network
MSC — Mobile-service Switching Controller
VLR — Visitor Location Register
HLR — Home Location Register
AuC — Authentication Server
GMSC — Gateway MSC
SGSN — Serving GPRS Support Node
GGSN — Gateway GPRS Support Node
ANc
2G MS (voice only)
2G+ MS (voice & data)
Node B
RNC
RNS
Iub
IuCS
IuPS
3G UE (voice & data)
Mc
CS-MGW
CS-MGWNb
PSTNMc
ATM
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1021
3G rel5 Architecture (UMTS)IP Multimedia Subsystem (IMS)
Gb/IuPS
A/IuCS
SS7
IP/ATM
BTS
BSCMSC Server
VLR
HSSAuC
GMSC server
BSS
SGSN GGSN
PSTN
CN
CD
GcGr
Gn Gi
Abis
Gs
B
H
IM — IP Multimedia sub-system
MRF — Media Resource Function
CSCF — Call State Control Function
MGCF — Media Gateway Control Function (Mc=H248,Mg=SIP)
IM-MGW — IP Multimedia-MGW
Nc
2G MS (voice only)
2G+ MS (voice & data)
Node B
RNC
RNS
Iub
3G UE (voice & data)
Mc
CS-MGW
CS-MGWNb
PSTNMc
IuCS
IuPS
ATM
IM
IPPSTN
Mc
MGCF
IM-MGW
MRF
CSCF
Mg
Gs
IP Network
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1022
3GPP Rel.6 Objectives
� IP Multimedia Services, phase 2– IMS messaging and group management
� Wireless LAN inter-working
� Speech enabled services– Distributed speech recognition (DSR)
� Number portability
� Other enhancements
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1023
3G rel6 Architecture (UMTS)IP Multimedia Subsystem (IMS)
Gb/IuPS
A/IuCS
SS7
IP/ATM
BTS
BSCMSC Server
VLR
HSSAuC
GMSC server
BSS
SGSN GGSN
PSTN
CN
CD
GcGr
Gn Gi
Abis
Gs
B
H
IM — IP Multimedia sub-system
MRF — Media Resource Function
CSCF — Call State Control Function
MGCF — Media Gateway Control Function (Mc=H248,Mg=SIP)
IM-MGW — IP Multimedia-MGW
Nc
2G MS (voice only)
2G+ MS (voice & data)
Node B
RNC
RNS
Iub
3G UE (voice & data)
Mc
CS-MGW
CS-MGWNb
PSTNMc
IuCS
IuPS
ATM
IM
IPPSTN
Mc
MGCF
IM-MGW
MRF
CSCF
Mg
Gs
IP Network
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1024
PSTN-to-Mobile Call
(STP)
(SCP)
PSTNPLMN
(SSP)(SSP)BSSMS
PLMN(Home)(Visitor)
(STP)
HLR
GMSC
(SSP)
VMSC
VLR
IAM
6
2
Where is the subscriber?
5
Routing Info
3Provide Roaming
4
SCP
1
IAM
514 581 ...
ISUP
MAP/ IS41 (over TCAP)
Signalingover SS7
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1025
Network Planes
� Like PSTN, 2G mobile networks have one plane for voice circuits and another plane for signaling
� Some elements reside only in the signaling plane– HLR, VLR, AuC, SMS Center, Voice Mail
– MSC -> MSC-S (signaling) + MGw (transport)
MSC
HLR
MSCVLR
Transport Plane (Voice, Data)
Signaling Plane (SS7 -> IP)MSC
VMS SMS-C
VLR
VLR AuC
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1026
Signaling in Core Network
� Historically based on SS7– ISUP and specific Application Parts
� Trend: Migration to SIGTRAN (SS7 over IP)
� GSM MAP and ANSI-41 services– Mobility, call-handling, O&M
– Authentication, supplementary services
– SMS, …
� Location registers for mobility management– HLR: home location register has permanent data
– VLR: visitor location register keeps local sub-set copy of roamer’s subscriber data
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1027
SS7 -- Signaling System #7
SSP
SSP SSP
STP
STP
STP
STP
SCP
SCP
PhonePhone
Voice Network
SS7 signaling network
Subscriber LineVoice TrunkSignaling Link
Appl.Appl.
Appl.
SSP = Service Switching PointSTP = Signal Transfer PointSCP = Service Control Point
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1028
Traditional STP Network- TDM or ATM based (SL or HSL)
Bandwidthlimitations
MSCMSC
STPSTP
STPSTP
HLRHLR
STPSTP
STPSTP
HLRHLR
MSCMSC MSCMSC MSCMSC MSCMSC MSCMSC MSCMSC--SS MSCMSC--SS MSCMSC--SS MSCMSC--SS
STPs are physical connection and aggregation points
Meshed/hierarchicalSTP network
Challenges:
• growing signaling load• broadband signaling capabilities
• new IP based applications• OPEX reduction
MGWMGW MGWMGW MGWMGW MGWMGWMGWMGW MGWMGW
ATM or IP based
SS7 routingintelligence in
SEPs and STPs
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1029
SS7 over IP Network
Bandwidthflexibility
L3/IP routingintelligence in
routers
SRP/SRP/
SGWSGW
SS7 routingintelligence only
in SEPs
IP NetworkIP Network
HLRHLR HLRHLR
MSCMSC MSCMSC MSCMSC--SS MSCMSC--SSMGWMGW MGWMGW
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1030
Physical Layer
SCCP
TCAP
IP
SCTP
M3UAMTP3
M2UA
SUA
M2PA
Physical Layer
SCCP
TCAP
IP
SCTP
M3UAMTP3
M2UA
SUA
M2PA
SIGTRAN Protocol Suite
IP and Physical Layer• Network-wide addressing• Routing, incl. Routing protocols• Quality of Service• Security
SCTP(Stream Control Transmission Protocol)
• Reliable, connection-oriented transport service on anunreliable IP network
• In-sequence delivery of packetswith delays acceptable for SS7
M3UA (MTP Level 3 User Adaptation)
• Mimics MTP3 services forMTP3 Users
• Supports some SS7 Network Management procedures
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1031
Physical Layer
SCCP
TCAP
IP
SCTP
M3UAMTP3
M2UA
SUA
M2PA
Physical Layer
SCCP
TCAP
IP
SCTP
M3UAMTP3
M2UA
SUA
M2PA
SIGTRAN Protocol Suite
MTP (Message Transfer Part)
Part of SS7. Responsible for reliable, unduplicated and in-sequence transport of SS7 messages between communication partners
SCCP (Signaling Connection Control Part)
provides routing, flow control, segmentation, connection-orientation, and error correction
TCAP (Transaction Capabilities Appl. Part)
Facilitate multiple concurrent dialogs between the same sub-systems on the same machines
© Ericsson AB 2008 Ericsson Internal Cellular Mobile Telephony 2008-12-1033
IMS Architecture
PS
UE
SGSN
Internet
HSS
IMS
P-CSCF
GGSN
Application Server
SIP phone
Media Server
Gi/Mb
Mw Mg
Mb
Mb
Gi
Mn
MGCF
TDM
IM-MGW
ISUP
Mb
Mb
CxGo
Signaling
CSCF — Call Session Control Function
IM-MGW — IM-Media Gateway
MGCF — Media Gateway Control Function
MRF — Media Resource Function
MRF
Gm
SIP
Mp
PSTN
CPE
ISC
CSCF