Elements of a Wireless Network!

network !infrastructure!

wireless hosts!laptop, PDA, IP phone!run applications!may be stationary (non-mobile) or mobile!

wireless does not always mean mobility!

network !infrastructure!

base station!typically connected to wired network!relay - responsible for sending packets between wired network and wireless host(s) in its “area”!

e.g., cell towers 802.11 access points !

Elements of a Wireless Network!

network !infrastructure!

wireless link!typically used to connect mobile(s) to base station!also used as backbone link !multiple access protocol coordinates link access !various data rates, transmission distance!

Elements of a Wireless Network!

down- or forward-link (!): base station to wireless host!up- or reverse-link ("): wireless host to base station!

network !infrastructure!

infrastructure mode!

base station connects mobiles into wired network!handoff: mobile changes base station providing connection into wired network!

Elements of a Wireless Network!

Ad hoc mode!

no base stations!nodes can only transmit to other nodes within link coverage!nodes organize themselves into a network: route among themselves!

Elements of a Wireless Network!

Mobile !Switching !Center!

Public telephone!network, and!

Internet!

Mobile !Switching !Center!

Components of Cellular Network Architecture!

•! connects cells to wide area net!•! manages call setup (more later!)!•! handles mobility (more later!)!

MSC!

•! covers geographical region!

•! base station (BS) analogous to 802.11 AP!

•! mobile users attach to network through BS!

•! air-interface: physical and link layer protocol between mobile and BS!

cell!

wired network!

Wikipedia: Dori!

Cellular Standards: 1G and 2G!Standard! Region

Origin!Year! Frequency Band

(MHz, FDD)!Modulation!

Multiple Access!

1G!analog!

(supports handoff, capacity increase by frequency reuse through cell splitting)!

AMPS! US!1971 (proposed)!

1982 (approved)!1983 (launched)!

800!

FM! FDMA!

NTT MCS! Japan! 1979! 400, 800!

NMT! Nordic! 1981! 450, 900!

(E)TACS! UK (Europe)! 1985(7)! 900!

C-Netz !

RTMS!Radicomm2000!

Germany!

Italy!France!

1981!

1985!1985!

165, 200, 400!

450!

2G!digital!

(increased capacity due to digital compression, supports circuit-switched data and SMS*)!

GSM!Europe!

China!US, Chile!

1990!

1993!1994!

900!

1800!1900!

GMSK!

TDMA!

IS-54!

IS-136!(D-AMPS,

(US-)TDMA, USDC)!

US (analog ctl)!

(all digital)!

1991!

1994!

800!

800, 1900!

DQPSK!

J!PDC! Japan! 1993! 800, 1500!

IS-95(A)!

(cdmaOne)!US! 1993! 800, 1900!

QPSK/

OQPSK!CDMA!

triband!(quad +850)!

motivation!

backward!compatible!

* piggy-back 160-char messages to voice traffic!

Alphabet Soup!•! 1x: one time RTT!

•! 3GPP: 3G Partnership Project!

•! AMPS: Advanced Mobile Phone System!

•! ARIB: Association of Radio Industries and Businesses (JP)!

•! BPSK: Binary Phase Shift Keying!

•! CAGR: Compound Annual Growth Rate !

•! CATT: China Academy of Telecommunications Technology!

•! CDMA: Code Division Multiple Access!

•! CSMA: Carrier Sense Multiple Access!

•! DECT: Digital Enhanced (European) Cordless Telephone!

•! DQPSK: Differential Quadrature Phase Shift Keying!

•! DS-SS: Direct Sequence Spread Spectrum!

•! EDGE: Enhanced Data-rate for Global (GSM) Evolution!

•! ETSI: European Telecommunications Standard Institute!

•! EV-DO: Evolution Data Optimized!

•! EV-DV: Evolution Data and Voice!

•! FDD: Frequency Division Duplex!

•! FDMA: Frequency Division Multiple Access!

•! FH-SS: Frequency Hopped Spread Spectrum!

•! FOMA: Freedom of Mobile Multimedia Access!

•! FPLMTS: Future Public Land Mobile Telephone System!

•! FSK: Frequency Shift Keying!

•! GMSK: Gaussian Minimum Shift Keying!

•! GPRS: Global Packet Radio Service!

•! GSM: Global System Mobile!

•! HSCSD: High Speed Circuit Switched Data!

•! HS[DU]PA: High Speed {Downlink, Uplink} Packet Access!

•! IEEE: Institute of Electrical and Electronics Engineers!

•! IMS: IP Multimedia Subsystem!

•! IMT-2000: International Mobile Telecommunication 2000!

•! IS-n: Electronic Industry Association (US) Interim Standard n

IS-136 GSM IS-95

GPRS EDGE CDMA-2000 UMTS

TDMA/FDMA

•! ISM: Industrial, Scientific, and Medical!

•! ITU: International Telecommunications Union!

•! JDC: Japanese Digital Cellular!

•! LTE: Long Term Evolution!

•! MCS: Mobile Communication System!

•! MSS: Mobile Satellite Services!

•! NMT: Nordic Mobile Telephony!

•! NTT: Nippon Telephone and Telegraph!

•! OFDM: Orthogonal Frequency Division Multiplexing!

•! OFDMA: Orthogonal Frequency Division Multiple Access!

•! PCS: Personal Communication System!

•! PDC: Personal Digital Cellular!

•! PHS: Personal Handyphone System!

•! QAM: Quadrature Amplitude Modulation!

•! QPSK: Quadrature Phase Shift Keying!

•! RF: Radio Frequency!

•! RTMS: Radio Telephone Mobile System!

•! RTT: Radio Transmission Technology!

•! TACS: Total Access Cellular System!

•! SMS: Short Message Service!

•! TDD: Time Division Duplex!

•! TDMA: Time Division Multiple Access!

•! TD-SCDMA: Time Division-Synchronous CDMA!

•! TIA: Telecommunications Industry Association (US)!

•! UMTS: Universal Mobile Telecommunications System!

•! USDC: US Digital Cellular!

•! UTRA(N): Universal (UMTS) Terrestrial Radio Access (Network)!

•! UWC(C): Universal Wireless Communications (Consortium)!

•! WARC: World Administrative Radio Conference!

•! WCDMA: Wideband CDMA!

•! WiFi: Wireless Fidelity!

•! WiMAX: Worldwide Interoperability for Microwave Access!

•! WLAN: Wireless LAN!

•! WRC-2000: ITU World Radio Conference!

Cellular Standards: 2.5G (and 2.75G)!Motivation: better support for data rate!

GSM:!•!9.6-14.4 Kbps!•! launched 1991

in Finland!•!900 m subs by

2003!

IS-136:!•!9.6 Kbps!

HSCSD:!•!14.4-57.6 Kbps!•!1-4 time slots/user!

IS-95(A):!•!9.6 (14.4) Kbps!

IS-95B (avg):!•!115.2 (64) Kbps!•!8 codes/user!

i-mode (1999):!•!9.6 Kbps!•!>33m subs by 6/02!

GPRS (2001):!•!115 Kbps (1 user)!•!20-30 Kbps (avg)!•!1-3 secs rtt!•!GMSK modulation!•!>280m subs by 05!

PDC:!•!GSM protocol!•!IS-136 physical!•!9.6 Kbps!•! limited to Japan!

cdma20001xRTT (1999):!•!144 Kbps, 50-70 Kbps avg!•!QPSK modulation!•!Release A: 384 Kbps!•! launched 10/2000 in S. Korea!•!150 m subs 12/04!

dedicated packet-switched network (billed by byte,

not by air time)!

3G!EDGE/EGPRS (2003):!•!384 Kbps (1 user)!•!100-130 Kbps (avg)!•!8PSK modulation!•!>36m subs by 2005!

Separate PSN for Data!

Cellular Standards: 3G!UN’s ITU’s plan IMT-2000 (a.k.a. FPLMTS, 1990)!Motivations:!•! single standard to support world-wide roaming!

•! 10 leading proposals in 98, 5 by Nov. 99, now down to 4!

•! data peak-rate requirements:!•! outdoor vehicular: 144 Kbps!•! outdoor pedestrian: 384 Kbps!•! indoor: 2 Mbps!

•! frequencies allocated:!•! UK auctioned off 5 "

licenses for USD 35.5b "in 4/2000!

•! DE auctioned off 4 "licenses for USD 46b"later same yr!

Chen & Guizani!

3G!

GSM!

IS-95!

IS-136!

PDC!

UWC-136!•!UWCC (US)!•!TDMA mod!

UTRA (1991)!•! ETSI (EU)!

WCDMA!•!ARIB (JP)!

TD-SCDMA!•!CATT (China)!•!>8 m GSM subs per month in late 2001!

cdma2000!•!TIA (US)!

WCDMA/UMTS (1999)!•! 3GPP, 1998!•! 2 Mbps, 220-320 Kbps (avg)!•! QPSK/BPSK!•! 275 ms rtt!•! GSM network and protocol!•! requires new equipments for UTRAN air/

radio interface!•! Release 99 (3/00)!•! >2.6b subs in 2008!

cdma2000 1xEV (Release B, 2001)!•! 3GPP2, 1999 (no EU rep)!•! EV-DO (Rev. 0):!

•! CDMA with TDM!•! QPSK/8PSK/16QAM modulation!•! peak rate 2 Mbps, reverse 150 Kbps!•! avg rate: 300-700 Kbps, reverse 70-90

Kbps!•! launched 2002 in S. Korea!•! >12 m subs by 2005!•! can connect directly to IP network!

TD-SCDMA (2000)!•!TD-SCDMA Forum!•!merged into 3GPP Release 4 (3/01)!•! co-exist with GSM RF equipment!•! 384 Kbps data!

NTT DoCoMo launched FOMA based on Release

99 (10/2001)!•! 64 Kbps circuit-

switched!•! 384/64 Kbps

packet-switched!

2003!

Voice Capacity Comparison!

Chen & Guizani!

Prior to 5/08:!•! China Telecom was the ISP for norhtern China!•! China Netcom was the ISP for southern China!•! China Mobile was the largest cell-phone service provider!•! China Unicom was the other cell-phone service provider!

On May 24, 2008, by gov’t decree:!•! China Mobile absorbed China Railcom!•! China Telecom absorbed China Satcom and the CDMA

business of China Unicom!•! China Unicom retains its GSM business and merged with

China Netcom!

The gov’t then issued 3G licenses to the three carriers:!

•! China Telecom: cdma2000 EV-DO!•! China Unicom: WCDMA!•! China Mobile: TD-SCDMA!

3G in China!

Characteristics of selected wireless link standards!

Indoor 10-30m

Outdoor 50-200m

Mid-range

outdoor 200m – 4 Km

Long-range

outdoor 5Km – 20 Km

.056

.384

1

4

5-11

54

IS-95, CDMA, GSM 2G

UMTS/WCDMA, CDMA2000 3G

802.15

802.11b

802.11a,g

UMTS/WCDMA-HSPDA, CDMA2000-1xEVDO 3G cellular

enhanced

802.16 (WiMAX)

802.11a,g point-to-point

200 802.11n

Da

ta r

ate

(M

bp

s) data

3.5G!

Mobile WiMAX (10/07 as IMT-2000)!•! IEEE!•!OFDM(A)!

•!QPSK/16QAM/64QAM!

•! 3-70 Mbps!

WCDMA/UMTS/UTRAN Release 4 (3/00): !•!QPSK/BPSK!•!2 Mbps!

cdma2000 1xEV-DO!(Release B, 2001)!•!QPSK/8PSK/16QAM

modulation!

•!2 Mbps/150 Kbps!

EV-DV (Release C):!•!3 Mbps!•! SS7 network!•! abandoned 2005!

EV-DO rev A (10/06):!•! 3/1.8 Mbps peak (16QAM)!•! 450-800/300-400 Kbps avg!•! all IP network!•! Verizon, Sprint, Alltel!

HSPA:"HSDPA (Release 5, 6/02): !•! 16QAM modulation!•! 14 Mbps, 2 Mbps (avg)!•! IP Multimedia Subsystem!

HSUPA/EUL"(Release 6, 12/04): !•! BPSK modulation!•! 5 Mbps (200 Kbps avg) !•! hybrid ARQ and faster

retransmissions!

cdma2000 3x!(EV-DO rev B, 2008):!•! 64QAM modulation!•! 5-15 Mbps down link!

HSPA+/HSPA Evolution!Release 7 (9/07): !•! 42/11 Mbps, 14 Mbps avg!•! 64QAM/16QAM!•! MIMO!

EDGE Evolution:!•! 1 Mbps peak, 400 Kbps avg!•! 16QAM and 32QAM mod!

Long Term Evolution (LTE) Release 8 (not yet ratified 4/09)!•! OFDM modulation for downlink:

170-300 Mbps!•! uplink: 86 Mbps!•! QPSK/16QAM/64QAM!•! MIMO!•! IP-based network!

http://www.3gpp.org/ftp/Specs/html-info/21101.htm!

Ultra Mobile Broadband!•! OFDMA air interface!•! 275 Mbps/75 Mbps up!•! abandoned Nov 2008!

Mobile Subscribers by Tech!

Wikipedia: sbsky!

Cellular Network Standards!Standard! Modulation! Data rate (avg)

in Kbps, K2=M!Multiple Access!

1G! AMPS! FM! -! FDMA!

2G!

GSM! GMSK! 9.6-14.4!

TDMA!

GPRS! GMSK! 115 (20-30)!

EDGE! 8PSK! 384 (100-130)!

EDGE Evolution! 16QAM/32QAM! 1K (400)!

IS-136! DQPSK! 9.6!

IS-95 (cdmaOne)! QPSK/OQPSK! 9.6!CDMA!

cdma2000 1xRTT! QPSK! 114 (50-70)!

3G!

cdma2000 1xEVDO (Rel 0)!QPSK/8PSK/16QAM!

2K/150 (500/80)!CDMA w/ TDM!

cdma2000 1xEVDO rev A! 3K/1.8K (700/350)!

WCDMA/UMTS! QPSK/BPSK! 2K (220-320)!

CDMA!UMTS HSPA! 16QAM/BPSK! 14K/5K (500-1K)!

UMTS HSPA+! 64QAM/16QAM! 42K/11K (14M)!

UMTS LTE!QPSK/QAM/OFDM!

170K-300K/86K! OFDMA!

WiMAX! 4K-120K! reservation!

4G! LTE-Advanced! (MIMO !4x4)! 100K-1M! OFDMA!

Range: < 2-8 km!Speed: < 250 km/h!

IEEE Wireless 802.1x Standards!Standard! Year! Frequency

Band (GHz)!Modulation! Data rate

Mbps!Range! Speed!

802.11!1987 (started)!

1997 (standard)!2.4!

DS-SS/DBPSK!

DS-SS/DQPSK!

1!

2!< 32 m

indoor!< 95 m

outdoor!

walking!802.11b!

(WiFi)!1999!

CCK-BPSK!

CCK-QPSK!

5.5!

11!

802.11a! 1999! 5! OFDM/24QAM! 54!

802.11g! 2003! 2.4! OFDM/64QAM! 1-54!

802.11n! not yet standard! (MIMO)! 200!

802.15.1!(Bluetooth)!

1994 (started)!

1999 (standard)!2.4! TDM-FHSS! .721-4! < 10 m!

N/A!802.16a"

(Line Of Sight)!2001! 10-66! OFDM!

QPSK!16QAM

64QAM! 4-70!

< 50 km!

802.16d"

(Non LOS)!2003! 2-11!

< 6-10

km!

802.16e!

(Mobile WiMAX,!S. Korea WiBro)!

2005! 2.3, 2.5, 3.3, 3.5!ScalableOFDM!

(MIMO)!

< 1-5

km!

< 120

km/h!

802.16m!

(WiMAX II)!

100 mobile!

1K fixed!

Mobility vs. Speed!

Wikipedia: Lee!

M

S

Master device

Slave device

Parked device (inactive) P

802.15: Personal Area Network

Replacement for cables "(mouse, keyboard, headphones)!

Ad hoc: no infrastructure!

Less than 10 m diameter!

Master/slaves:!•! slaves request permission to send"

(to master)!

•! master grants requests!

802.15: evolved from Bluetooth specification!•! a bluetooth network (piconet) supports 2-7 gadgets!

•! each gadget given a 12-bit address!

•! supports gadget authentication and data encryption!

•! uses frequency hopping spread spectrum (signal occupies diff freqs, in a given pattern and duration, as xmission progresses)!

•! uses FEC, CRC, and ARQ!

M radius of

coverage

S

S S

P

P

P

P

802.16: WiMAX!Like 802.11 & cellular: infrastructure model!•! transmissions to/from base station by

hosts with omnidirectional antenna!

•! base station-to-base station backhaul with point-to-point antenna!

Unlike 802.11:!•! range ~ 6 miles (“city rather than

coffee shop”)!

•! ~14 Mbps!

•! originally intended to provide an alternative to ADSL/cable for “last-mile” connectivity!

•! mobile WiMAX provides an alternative to UMTS and WiMAX II to to LTE-Advanced!

point-to-multipoint!

point-to-point!

References!Books:!Rappaport, T.S., Wireless Communications: Principles and Practice, 2nd ed., Prentice-Hall, 2002!

•!Good coverage of 1G systems, provides intuitive understanding of the maths, one new chapter provides high-level review of 3G systems in 2nd ed. [TK 5103.2.R37 2002]!

Kwok, Y-K. R. and Lau, V.K.N., Wireless Internet and Mobile Computing, Wiley, 2007!

•!Good coverage of 2G systems, surprising not much of 3G given the publication date [TK 5103.2.K95 2007]!

Chen, H-H. and Guizani, M., Next Generation Wireless Systems and Networks, Wiley, 2006!

•!Good coverage of 3G systems, including cdma2000 and TD-SCDMA, interesting global politics

coverage [TK 5103.2.C455 2006]!

Korhonen, J., Introduction to 3G Mobile Communications, 2nd ed., Artech-House, 2003!

•!Provides a European point of view, focus on UTRAN (WCDMA) [TK 5103.2.K671 2003]!

Dahlman, E., et al., 3G Evolution: HSPA and LTE for Mobile Broadband, 2nd ed., Academic Press, 2008!

•!Like the title says!

Web sites:!•! 3GPP (3gpp.org) and GSM World (gsmworld.com)!

•! WiMAX Forum (wimaxforum.org)!

•! CDMA Developers Group (cdg.org) and 3GPP2 (3gpp2.org)!

•! TD-SCDMA (tdscdma-forum.org)!