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1.11.2005 T-110.5120 Next Generation Wireless Networks 1
Cellular Radio Networks
Samiseppo Aarnikoivu
Juha Winter
1.11.2005 T-110.5120 Next Generation Wireless Networks 2
Contents
� Introduction 3
� Core Development 6
� 2G Radio Development 10
� 3G Radio Development 13
� Long-Term Radio Evolution 17
� Service Evolution 19
� Summary and Conclusions 23
� References 24
� Additional Material 25
1.11.2005 T-110.5120 Next Generation Wireless Networks 3
Introduction, 1/3
� Current 2G/3G architecture
� 3GPP Release 4 is being deployed
1.11.2005 T-110.5120 Next Generation Wireless Networks 4
Introduction, 2/3
� Current 2G/3G performance
� End-user throughput and latency
150-250350-700~900Average RTT (ms)
384 (DL) / 64-384 (UL)
236 (pract.), 384 (theor.)
85 (pract.), 115 (theor.)
Peak rate (kbps)
In line with peak rates
80−160 (2 slots),
160−200 (4 slots)40−50
Typical rate (kbps)
WCDMA (UMTS)
EGPRS (EDGE)GPRS (GSM)
1.11.2005 T-110.5120 Next Generation Wireless Networks 5
Introduction, 3/3
� Current 2G/3G services� Basic services
� Voice telephony, CS and PS data
� Messaging
� SMS, MMS, Instant Messaging (IM)
� Push-to-Talk over Cellular (PoC)
� E-mail, web browsing
� Video telephony
� Streaming media
� Audio streaming
� Video streaming/sharing
1.11.2005 T-110.5120 Next Generation Wireless Networks 6
Core Development
� There is a clear need to build only one core network that provides access-independent and flexible services:� AAA� Call processing and management� Mobility� Secure transport with QoS support� Gateways� Network management etc.
� Core network machinery and interfaces are a vital counterpart and enabler for the actual radio access evolution
1.11.2005 T-110.5120 Next Generation Wireless Networks 7
IP Multimedia Subsystem (IMS)
� Defines a horizontal architecture of service enablers and common functions providing� Interoperability� Roaming� Bearer control� Charging� Security
� Generic architecture for offering VoIP and multimedia services in multiple networks� Migration path to an all-IP
network
� Utilizes heavily the Session Initiation Protocol (SIP, RFC3261)
� Trials and first commercial deployments are on-going
Source: Ericsson
AS = Authentication ServerCSCF = Call Session Control FunctionHSS = Home Subscriber ServerMRF = Media Resource FunctionSG/MGCF = Service Gateway / Media Gateway Control Function
1.11.2005 T-110.5120 Next Generation Wireless Networks 8
Multi-Access
� Modern terminals already contain a number of air interfaces, and a lot more can be expected
� Operators, enterprises or even end users are able to extend the access networks with what they already may have
� Interworking aspects are addressed in many 3GPP Release 6 specifications
� Focus is at least on WLAN and WiMAX
Source: Nokia
BT = BluetoothDVB-H = Digital Video Broadcasting for HandheldsMBWA = Mobile Broadband Wireless AccessNFC = Near Far CommunicationRFID = Radio Frequency IdentificationUWB = Ultra Wide Band
1.11.2005 T-110.5120 Next Generation Wireless Networks 9
Unlicensed Mobile Access (UMA)
� Network coverage enhancement, which provides access to 2G services over unlicensed frequency spectrum� WLAN, WiMAX� Bluetooth etc.
� Seamless mobility between 2G BSS and UMA accesses� Originally developed by Kineto, now a 3GPP standard� First commercial products out in 1H/2006
1.11.2005 T-110.5120 Next Generation Wireless Networks 10
2G Radio Development, 1/3
� Dual Transfer Mode (DTM)� Simultaneous voice & data connections in
GSM/EDGE
� Specified in 3GPP TS 43.055
� Mixed use of time slots for CS & PS traffic� DTM multi-slot classes (5, 9, 11) and high multi-slot
classes with Enhanced Dynamic Allocation (EDA)
� 1 time slot for CS services (DL/UL), multiple for PS data, e.g. CS 1/1 + PS 2(DL)/1(UL)
� E-mail, SMS and web browsing during voice calls ⇒improved usability
� New services for GSM/EDGE
� Video sharing (previously only in 3G!)
1.11.2005 T-110.5120 Next Generation Wireless Networks 11
2G Radio Development, 2/3
� Why DTM?� Increased flexibility of services for the end-user in
GSM/EDGE networks� New revenue opportunities for operators due to new
(enabled) services� Enhanced service continuity in GSM/EDGE/WCDMA
multi-radio networks� WCDMA already supports simultaneous CS & PS
connections, but coverage may be limited in some areas
� Incremental upgrade to existing BSS network elements and terminals
� Only a SW upgrade may suffice, depending on vendor specific implementation
� First DTM compliant terminals already on the market, commercial launches expected in early 2006
1.11.2005 T-110.5120 Next Generation Wireless Networks 12
2G Radio Development, 3/3
� EDGE Evolution� Will be standardized from Release 7 onward
� Aims to tighten the gap between current GSM/EDGE and WCDMA/High Speed Packet Access (HSPA) technology
� Improved service performance, enhanced service continuity, more cost-efficient coverage
� Increased spectral efficiency
� Offers 2−3 fold increase in data rates
� Halves the latency (RTT)
� Can be implemented to existing GSM/EDGE networks with low network impact
� Backwards compatible with existing EDGE solutions
1.11.2005 T-110.5120 Next Generation Wireless Networks 13
3G Radio Development (3.5G)
� Current 3G networks have not been able to actually respond to the high expectations of mobile broadband� Performance not on par with xDSL� Relatively high costs for operators as well as end
customers
� A number of competitive techniques are now beginning to enter the market� CDMA 450� Flash-OFDM� Mobile WiMAX (806.11e)
� 3GPP Releases 5 and 6 will address these issues� 3G network architecture can be optimized to be
more cost-effective for packet data
1.11.2005 T-110.5120 Next Generation Wireless Networks 14
High Speed Downlink Packet Access (HSDPA)
� New shared channels (HS-SCCH and HS-DSCH) with functionalities pushed to Node B� Adaptive modulation and
coding (16-QAM & QPSK)� Fast scheduling (2 ms)� Fast retransmission (HARQ)
� DL Throughput and delay improvements� ~1500 kbps (first phase),
>10 Mbps possible in practice
� RTT < 100 ms
� Software update (some vendors may require HW update as well)
� First commercial HSDPA network has already been opened (O2/Isle of Man), mainstream launches will happen during 2006
Source: Siemens
1.11.2005 T-110.5120 Next Generation Wireless Networks 15
High Speed Uplink Packet Access (HSUPA)
� New uplink data path (E-DCH) below the RLC layer parallel to DCH, similar improvements as HSDPA (except for adaptive modulation, which is not feasible)� Layer1 hybrid ARQ� Node B based scheduling for uplink� Frame sizes 2 ms & 10 ms
� UL Throughput and delay improvements� ~1 Mbps (first phase)
>5 Mbps possible� RTT < 50 ms
� Software update (some vendors may require HW update as well)� Commercial launches will probably start to happen in late 2006 -
early 2007
Source: Nokia
1.11.2005 T-110.5120 Next Generation Wireless Networks 16
PS-optimized Network Architecture
� UTRAN architecture is designed to provide both CS and PS services� Layered functionality between
Node B and RNC� ATM-based transmission etc.
� UTRAN evolution is clearly happening with PS services� Air interface may no longer be
the actual bottleneck
� Nokia’s Internet-HSPA is one solution to optimize the already deployed network for PS services� I-HSPA is also sold for
greenfield operators as an alternative for other mobile broadband techniques
� Scalability, lower cost� Better RTT
1.11.2005 T-110.5120 Next Generation Wireless Networks 17
Long-Term Radio Evolution
� UTRAN LTE is a 3GPP research item for Release 8� Also known as 3.9G or “Super 3G”
� Still a long way from being commercial (2009?)
� Aims at peak data rates of 200 Mbps (DL) and 100 Mbps (UL)
� Optimized for PS only
� New architecture
� New modulation
� Spectrum and bandwidth flexibility
� Lower latency (<30 ms?)
� Interworking with 3.5G evolution
1.11.2005 T-110.5120 Next Generation Wireless Networks 18
Potential 3.9G Enablers
� MIMO (Multiple Input Multiple Output)� Multiple antennas on both receiver and transmitter
side� Increased capacity (e.g. 3x) due to multi-stream
transmissions and code reuse� Already accepted to 3GPP Release 7� Demands high processing power
� OFDM (Orthogonal Frequency Division Multiplexing)� Already used e.g. in ADSL and DVB transmission� Available bandwidth is split into many (100-8000)
narrowband channels� Low symbol rate => high multipath delay tolerance
=> allows high spectrum efficiency
1.11.2005 T-110.5120 Next Generation Wireless Networks 19
Service Evolution, 1/4
� New speech codecs� Adaptive Multi-Rate Wideband (AMR-WB)
� Standardized by both 3GPP (TS 26.171) and ITU-T (G.722.2), intended to be used in UMTS
� Multi-mode speech codec supporting 9 wide band speech coding modes with bit rates 6.6−23.85 kbps
� Wider speech bandwidth of 50−7000 Hz compared to narrowband speech codecs ⇒ excellent speech quality
� Performs reasonably well also under severe background noise conditions and in the case of music as input
� Adaptive Multi-Rate Wideband Plus (AMR-WB+)� Supports even higher sampling rates and stereo signals
(for high quality music)� Greatly improved generic audio coding capabilities due to
use of transform coding in addition to Algebraic Code Excited Linear Prediction (ACELP)
1.11.2005 T-110.5120 Next Generation Wireless Networks 20
Service Evolution, 2/4
� Rich media and mobile multicast� Increased data transfer capabilities are a key
enabler for broadcast/mobile/Internet convergence services
� Mobile TV (IP datacast over DVB-H)� High quality audio/music streaming (e.g.
mobile jukebox)� Scheduled audio/video distribution, push
media� Video announcements� Real-time, content-rich multiplayer games� File distribution between multiple parties,
mobile P2P systems
1.11.2005 T-110.5120 Next Generation Wireless Networks 21
Service Evolution, 3/4
� Voice over IP (VoIP)� Cost-efficient telephony using existing IP network
infrastructure, mobile access through IMS� Already massively utilized by telco carriers and corporate
offices but also increasingly popular with private consumers (e.g. Skype)
� Natural consequence of the all-IP convergence� VoIP codecs
� Internet Low Bit-rate Codec (iLBC)� Dual rate operation: 15.2 kbps with 20 ms frames or 13.33
kbps with 30 ms frames
� ITU-T G.723.1� Capable of achieving up to 12:1 compression ratio� Dual rate operation: 5.3 kbps or 6.3 kbps
� ITU-T G.729(/A/AB)� 8 kbps, speech quality similar to that of 32 kbps ADPCM
landline connections
1.11.2005 T-110.5120 Next Generation Wireless Networks 22
Service Evolution, 4/4
� Multimedia Broadcast/Multicast Service� Point-to-multipoint (p-t-m) bearer service enabling
efficient unidirectional multimedia content delivery to mobile subscribers
� Two modes of operation� Multicast
� Users need to subscribe to and join specific services
� Broadcast� Service data is sent to predefined network area without
system knowledge of the presence of potential users, no charging data collected
� Impact on RAN radio resource and mobility management, type of used radio bearers in WCDMA
� Idle-mode reception: UE must be able to receive data also when idle (no signaling connection to the network) to reduce battery power consumption
1.11.2005 T-110.5120 Next Generation Wireless Networks 23
Summary and Conclusions
� There are several different (and changing) drivers and enablers for network development and new services – performance is only one of them
� Radio evolution is pushed by increased competition and interworking support within the core network, cost goes down all the time
� 2G/3G has the most vendors and users, so it will be hard to beat
� Network capabilities and resulting services will be at least an order of magnitude better and more versatile than today
� “You ain’t seen nothing yet”
1.11.2005 T-110.5120 Next Generation Wireless Networks 24
References
1. http://www.3gpp.org/specs/specs.htm
2. http://www.ericsson.com/products/white_papers_pdf/ims_ip_multimedia_subsystem.pdf
3. http://www.ietf.org/rfc/rfc3261.txt
4. http://www.sipcenter.com/
5. http://www.wimaxforum.org/
6. http://www.umatechnology.org/
7. http://www.europe.nokia.com/BaseProject/Sites/NOKIA_MAIN_18022/CDA/Categories/Business/Technologies/EDGE/_Content/_Static_Files/nokia_edge_evolution_wp.pdf
8. http://www.netlab.hut.fi/opetus/s38310/04-05/Kalvot_04-05/H%E4m%E4l%E4inen_070605.ppt
9. http://www.nokia.com/NOKIA_COM_1/Operators/Mobile_Operators_&_Service_Providers/Mobile_Networks/WCDMA/radio_network_evolution_a4_02-2005_net.pdf
10. http://www.nokia.com/NOKIA_COM_1/About_Nokia/Press/White_Papers/pdf_files/hspa_a4_02-2005_net.pdf
11. http://www.siemens.com/Daten/siecom/Germany/COM/Internet/Mobile_Networks/WORKAREA/com_mnde/templatedata/Deutsch/file/binary/HSDPA_0105_1306647.pdf
12. http://www.nortel.com/solutions/wireless/collateral/nn_112020.06-01-05.pdf
13. http://en.wikipedia.org/wiki/COFDM
14. http://www.mobiletv.nokia.com/resources/files/mobile_tv_brochure_2005.pdf
Further information: http://www.google.com
1.11.2005 T-110.5120 Next Generation Wireless Networks 25
Additional Material
HSDPA User Plane
HSUPA User Plane
1.11.2005 T-110.5120 Next Generation Wireless Networks 26
HSDPA User Plane
RNCNode BUE
WCDMA L1
MAC
RLC
WCDMA L1
MAC-hs FP
Transport Transport
FP
MAC-d
RLC