1. Original Slides from Brough Turner
Our G-enealogy
Original Slides from Brough Turner
Founder & CTO
Ashtonbrooke.com
Original slides:

2. Our G-enealogy Brief history of cellular wireless telephony
Radio technology: TDMA, CDMA, OFDMA
Mobile core network architectures
Demographics & market trends today
3.5G, WiMAX, LTE & 4G migration paths 2

3. Mobiles overtake fixed
Source: ITU World ICT Indicators, June 2008 3

4. Mobile Generations G Summary Data Rates 1 2 2.5 3 3.5 4 Analog
Typical 2.4 Kbps; max 22 Kbps 2
Digital – TDMA, CDMA
Kbps (circuit data)
2.5
GPRS – mux packets in voice timeslots
Kbps 3
Improved modulation, using CDMA variants
50 – 144 Kbps (1xRTT); 200 – 384 Kbps (UMTS); 500 Kbps – 2.4 Mbps (EVDO)
3.5
More modulation tweaks
2–14 Mbps (HSPA), then 28 Mbps & 42/84 Mbps future evolution 4
New modulation (OFDMA); Multi-path (MIMO); All IP
LTE: potentially >100 Mbps with adequate spectrum (20 MHz)

5. First Mobile Radio Telephone, 1924
Courtesy of Rich Howard
first two-way, voice-based radio telephone
First two-way, voice-based radio telephone 5

6. Cellular Mobile Telephony
Antenna diversity
Cellular concept
Bell Labs (1957 & 1960)
Frequency reuse
typically every 7 cells
Handoff as caller moves
Modified CO switch
HLR, paging, handoffs 1 2 3 4 5 6 7
Antenna diversity, also known as space diversity, is any one of several wireless diversity schemes that uses two or more antennas to improve the quality and reliability of a wireless link.
CO: central office
Home Location Register (HLR) 6

7. First Generation (nearly all retired)
Advanced Mobile Phone Service (AMPS)
US trials 1978; deployed in Japan (’79) & US (’83)
800 MHz; two 20 MHz bands; TIA-553
Nordic Mobile Telephony (NMT)
Sweden, Norway, Demark & Finland
Launched 1981
450 MHz; later at 900 MHz (NMT900)
Total Access Communications System (TACS)
British design; similar to AMPS; deployed 1985 7

8. 2nd Generation – digital systems
Leverage technology to increase capacity
Speech compression; digital signal processing
Utilize/extend “Intelligent Network” concepts
Improve fraud prevention; Add new services
Wide diversity of 2G systems
IS-54/ IS-136 Digital AMPS; PDC (Japan)
DECT and PHS; iDEN
IS-95 CDMA (cdmaOne)
GSM 8

9. 2G “CDMA” (cdmaOne) Code Division Multiple Access
all users share same frequency band
discussed in detail later as CDMA is basis for 3G
Qualcomm demo in 1989
claimed improved capacity & simplified planning
First deployment in Hong Kong late 1994
Major success in Korea (1M subs by 1996)
Adopted by Verizon and Sprint in US
Easy migration to 3G (same modulation) 9

10. GSM – Global System for Mobile
Originally “Groupe Spécial Mobile ”
joint European effort beginning 1982
Focus: seamless roaming all Europe
Services launched 1991
time division multiple access (8 users per 200KHz)
900 MHz band; later 1800 MHz; then 850/1900 MHz
GSM – dominant world standard today
well defined interfaces; many competitors; lowest cost to deploy
network effect took hold in late 1990s 10

11. Source: Wireless Intelligence / GSM Association
GSM Dominant Today
GSM+3GSM used by 88% of subscribers worldwide
Asia leads with 42% of all mobile subscriptions
AT&T and T-Mobile use GSM/3GSM in US today
Source: Wireless Intelligence / GSM Association
GSM Subscribers 11

12. GSM substantially enhanced
Widely deployed  significant payback for enhancements
HSCSD - high speed circuit-switched data
GPRS - general packet radio service
Synchronization between cells
Minimize interference; help fix mobile’s location
AMR vocoder – increase capacity (& fidelity)
Frequency hopping (to overcome fading)
Discontinuous transmission (more calls/ cell)
Cell overlays with reuse partitioning 12

13. 1G, 2G, 3G Multi-Access Technologies
Courtesy of Petri Possi, UMTS World
4G and future wireless systems optimize a
combination of frequency, time and coding
e.g. OFDMA & SC-FDMA (discussed later) 13

14. 2G & 3G – Code Division Multiple Access
Spread spectrum modulation
originally developed for the military
resists jamming and many kinds of interference
coded modulation hidden from those w/o the code
All users share same (large) block of spectrum
All 3G radio standards based on CDMA
CDMA2000, W-CDMA and TD-SCDMA 14

15. Courtesy of Suresh Goyal & Rich Howard15

16. The 3G Vision Universal global roaming Increased data rates
Sought 1 standard (not 7), (but got 3: 3GSM, CDMA 2000 & TD-SCDMA)
Increased data rates
Multimedia (voice, data & video)
Increased capacity (more spectrally efficient)
Data-centric architecture (ATM at first, later IP)
But deployment took much longer than expected
No killer data app; new spectrum costly; telecom bubble burst; much of the vision was vendor-driven 16

17. 3G Radio technology today
CDMA 2000 – Multi Carrier CDMA
Evolution of IS-95 CDMA; but now a dead end
UMTS (W-CDMA, HSPA) – Direct Spread CDMA
Defined by 3GPP
Asynchronous CDMA
TD-SCDMA – Time Division Synchronous CDMA
Defined by Chinese Academy of Telecommunications Technology under the Ministry of Information Industry
Paired spectrum bands
Single spectral band with time division duplexing 17

18. Why CDMA 2000 lost out Had better migration story from 2G to 3G
Evolution from original Qualcomm CDMA (IS-95)
cdmaOne operators didn’t need additional spectrum
Higher data rates than UMTS, at least at first
Couldn’t compete with GSM’s critical mass
Last straw when Verizon Wireless selected 3GPP’s Long Term Evolution (LTE) for their 4G network
Verizon selection 11/2007
Qualcomm abandons further development 11/2008 18

19. 3GPP (3rd Generation Partnership Project)
Japan
USA
Partnership of 6 regional standards groups, which translate 3GPP specifications to regional standards
Controls evolution of GSM, 3GSM (UMTS, WCDMA, HSPA) & LTE

20. UMTS (3GSM) is market leader
GSM evolution: W-CDMA, HSDPA, HSPA, +…
leverages GSM’s dominant position
Legally mandated in Europe and elsewhere
Requires substantial new spectrum
5 MHz each way (symmetric) at a minimum
Slow start (was behind CDMA 2000), but now the accepted leader
Network effect built on GSM’s >80% market share
Surely LTE will benefit in the same fashion… 20

21. TD-SCDMA (Time division synchronous CDMA)
Chinese development
IPR bargaining tool with West? Late to market, but big deployment plans
Single spectral band
unpaired spectrum; as little as 1.6 MHz; time division duplex (TDD) with high spectral efficiency
Power amplifiers must be very linear
relatively hard to meet specifications 21

22. China 3G Largest mobile market in world (630 M subs)
Largest population in world (1.3 billion)
Home-brew 3G standard: TD-SCDMA
3G licenses were delayed until TD-SCDMA worked
2008 trials: 10 cities, 15K BSs & 60K handsets
3G granted January 2009
China Mobile: TD-SCDMA
China Unicom: 3GSM (UMTS)
China Telecom: CDMA 2000 22

23. 3G Subscribers (Q4 2011) http://kpcb.com/insights/2012-internet-trends23

24. Diverse Mobile Wireless Spectrum24

25. Wireless Migration

26. Wireless Subscribers in Korea
2012.2
2012.3
Changes
+/-
+/- %
방송통신위원회

27. 4G OFDM →OFDMA MIMO LTE 3G WiMAX Wi-Fi 2G UMTS/HSPA
Wireless capacity / throughput
CDMA
First cell phones
GSM
Increasing throughput and capacity
AMPS
1970
1980
1990
2000
2010

28. ITU Framework Pervasive connectivity WLAN - WMAN - WWAN
ITU – United Nations telecommunications standards organization
Accepts detailed standards contributions from 3GPP, IEEE and other groups
3GPP – WWAN (wireless wide area network)
IEEE – WMAN (wireless metropolitan area network)
IEEE – WLAN (wireless local area network) 28

29. ITU-R Mobile Telecommunications
IMT-2000
Global standard for third generation (3G) wireless
Detailed specifications from 3GPP, 3GPP2, ETSI and others
IMT-Advanced
New communications framework: deployment ~2010 to 2015
Data rates to reach around 100 Mbps for high mobility and 1 Gbps for nomadic networks (i.e. WLANs)
High mobility case via either or both evolved LTE & WiMAX
802.11ac and ad addressing the nomadic case 29

30. LTE highlights Sophisticated multiple access schemes
DownLink: OFDMA with Cyclic Prefix (CP)
UpLink: Single Carrier FDMA (SC-FDMA) with CP
Adaptive modulation and coding
QPSK, 16QAM, and 64QAM
1/3 coding rate, two 8-state constituent encoders, and a contention-free internal interleaver
Advanced MIMO spatial multiplexing
(2 or 4) x (2 or 4) downlink and uplink 30

31. 4G Technology – OFDMA Orthogonal Frequency Division Multiple Access
Supercedes CDMA used in all 3G variants
OFDMA = Orthogonal Frequency Division Multiplexing (OFDM) plus statistical multiplexing
Optimization of time, frequency & code multiplexing
OFDM already deployed in a & g
Took Wi-Fi from 11 Mbps to 54 Mbps & beyond 31

32. Orthogonal Frequency Division Multiplexing
Many closely-spaced sub-carriers, chosen to be orthogonal, thus eliminating inter-carrier interference
Varies bits per sub-carrier based on instantaneous received power 32

33. Statistical Multiplexing (in OFDMA)
Dynamically allocate user data to sub-carriers based on instantaneous data rates and varying sub-carrier capacities
Highly efficient use of spectrum
Robust against fading, e.g. for mobile operation 33

34. FDMA vs. OFDMA OFDMA more frequency efficient
Dynamically map traffic to frequencies based on their instantaneous throughput
FDMA
Channel
Guard band

35. 4G Technology - MIMO
Multiple Input Multiple Output smart antenna technology
Multiple paths improve link reliability and increase spectral efficiency (bps per Hz), range and directionality 35

36. Municipal Multipath Environment36

37. SDMA = Smart Antenna Technologies
Beamforming
Use multiple-antennas to spatially shape the beam
Spatial Multiplexing a.k.a. Collaborative MIMO
Multiple streams transmitted
Multi-antenna receivers separate the streams to achieve higher throughput
On uplink, multiple single-antenna stations can transmit simultaneously
Space-Time Codes
Transmit diversity such as Alamouti code reduces fading
2x2 Collaborative MIMO give 2x peak data rate by transmitting two data streams 37

38. 4G Technology – SC-FDMA Single carrier multiple access
Used for LTE uplinks
Being considered for m uplink
Similar structure and performance to OFDMA
Single carrier modulation with DFT-spread orthogonal frequency multiplexing and FD equalization
Lower Peak to Average Power Ratio (PAPR)
Improves cell-edge performance
Transmission efficiency conserves battery life 38

39. Key Features of WiMAX and LTE
OFDMA (Orthogonal Frequency Division Multiple Access)
Users are allocated a slice in time and frequency
Flexible, dynamic per user resource allocation
Base station scheduler for uplink and downlink resource allocation
Resource allocation information conveyed on a frame‐by frame basis
Support for TDD (time division duplex) and FDD (frequency division duplex) DL UL
FDD
Paired channels
TDD: single frequency channel for uplink and downlink

40. 3G/4G Comparison Peak Data Rate (Mbps) Access time (msec) Downlink
Uplink
HSPA (today)
14 Mbps
2 Mbps
msec
HSPA (Release 7) MIMO 2x2
28 Mbps
11.6 Mbps
HSPA + (MIMO, 64QAM Downlink)
42 Mbps
WiMAX Release 1.0 TDD (2:1 UL/DL ratio), 10 MHz channel
40 Mbps
10 Mbps
40 msec
LTE (Release 8), 5+5 MHz channel
43.2 Mbps
21.6 Mbps
30 msec

41. WiMAX vs. LTE Commonalities Differences IP-based OFDMA and MIMO
Similar data rates and channel widths
Differences
Carriers are able to set requirements for LTE through organizations like NGMN and LSTI, but cannot do this as easily at the IEEE-based
LTE backhaul is, at least partially, designed to support legacy services while WiMAX assumes greenfield deployments

42. Commercial Issues LTE Deployments likely slower than projected But
Eventual migration path for GSM/3GSM, i.e. for > 80% share
Will be lowest cost & dominant in 2020
WiMAX
2-3 year lead, likely maintained for years
Dedicated spectrum in many countries
But
Likely < 15% share by 2020 & thus more costly

43. 3G Partnership Project Defines migration GSM to UMTS/ 3GSM to LTE *
Release
Specs complete
First deployed
Major new features defined 98
1998
Last purely 2G GSM release 99
1Q 2000
2003
W-CDMA air interface 4
2Q 2001
2004
Softswitching IP in core network 5
1Q 2002
2006
HSDPA & IP Multimedia System (IMS) 6
4Q 2004
2007
HSUPA, MBMS, GAN, PoC & WLAN integration 7
4Q 2007
future
HSPA+, Better latency & QoS for VoIP 8
4Q 2008
LTE, All-IP *
* Rush job?
W-CDMA – Wideband CDMA modulation
HSxPA – High Speed (Download/Upload) Packet Access
MBMS – Multimedia Broadcast Multicast Service
GAN – Generic Access Network
PoC – Push-to-talk over Cellular
LTE – Long Term Evolution, a new air interface based on OFDM modulation 43

44. Core Network Architecture
Two widely deployed architectures today
3GPP evolved from GSM-MAP
Used by GSM & 3GSM operators (88% of subs globally)
“Mobile Application Part” defines signaling for mobility, authentication, etc.
3GPP2 evolved from ANSI-41 MAP
ANSI-41 used with AMPS, TDMA & CDMA 2000
GAIT (GSM ANSI Interoperability Team) allowed interoperation, i.e., roaming
Evolving to common “all IP” vision based on 3GPP 44

45. Core Network Architecture
Home Subscriber Server (HSS) performs AAA and subscriber database functionality, eliminating the need for a separate Radius server
The Policy and Charging Rules Function (PCRF) server is an important element, taking care of the direct control of resources (quality of service) according to user profile
Mobility Management Entity (MME) has a role similar to that of the Serving GPRS Support Node (SGSN) in the 3G packet core, except that it only carries the signalling path
Serving GW (SGW) has inherited the SGSN's bearer role in 4G, transporting large amounts of traffic
Packet Data Network Gateway (PDN GW) has replaced the Gateway GPRS Support Node (GGSN) in the 3G packet core, thus having the Network Access Server (NAS) role
eNodeB serves in 4G instead of NodeB and Radio Network Controller (RNC) in 3G

46. Summary Brief history of cellular wireless telephony
Radio technology: TDMA, CDMA, OFDMA
Mobile core network architecture 46