1. ECET 581/CPET/ECET 499 Mobile Computing Technologies & Apps
Mobile Networking & Communication Infrastructures
Lecture 2
Paul I-Hai Lin, Professor
Electrical and Computer Engineering Technology
Indiana University-Purdue University Fort Wayne
January 16, 2007

2. Mobile Networking & Communication Infrastructures
Wireless Mobile Networking: An Introduction
Infrastructure Network Topology
Ad Hoc Network Topology
Mobile Communication Infrastructures 1G 2G
2.5G 3G
Bluetooth, IrDA, IrFM, OMA (Open Mobile Alliance) Device Management
January 16, 2007

3. Cellular Phone System
List of Mobile Network Operators,
January 16, 2007

4. Mobile Network Operators
T-Mobile (Germany)
GMS, GPRS, EDGE, UMTS, HSDPA (High Speed Downlink Packet Access)
Cingular (U.S.)
GSM, GPRS, EDGE, UMTS, HSDPA (TDMA)
Verizon (U.S.)
CDMA, CDMA2000 1x, EV-DO (Evolution-Data Optimized data standard)
Sprint/Nextel (U.S.)
CDMA, CDMA2000 1x, EV-DO, iDEN (Integrated Digital Enhanced Network)
January 16, 2007

5. Wireless Mobile Networking
Infrastructure Network Topology
Fixed infrastructure with Wide Area Network coverage
Mobile ↔ Mobile devices
Mobile ↔ Fixed Computer Node
Mobile device ↔ Servers
January 16, 2007

6. Wireless Mobile Networking (cont.)
Infrastructure Network Topology (WAN Access)
Fiber-to-the-House, Cable Modem, DSL, Dial-up
Wireless Access Points/Routers
Wired Routers
LAN, WLAN, WiMAX
January 16, 2007

7. Wireless Mobile Networking (cont.)
Ad Hoc Network Topology
Single-Hop Peer-to-Peer
Multi-hop Ad Hoc Network
January 16, 2007

8. Wireless Mobile Networking (cont.)
Mobile Ad Hoc Networks (MANET) Routing Protocols
RFC2501, RFC3561, RFC3626
RFC3684
MANET Charter,
MANET Internet Drafts,
National Institute of Standards, MANET Projects,
OPNET – MANET Discrete Event Simulation,
January 16, 2007

9. Mobile Communication Infrastructures
1G Analog FM
2G TDMA-FDMA/ CDMA (Code Division Multiple Access)
2.5 G – extend 2G system by adding packet-switched connection
GPRS (General Packet Radio Service; for data packet service on GSM network)
EDGE (Enhanced Data GSM Evolution, up to 384 Kbps)
Support WAP, search, directory services, etc 3G
January 16, 2007

10. The Mobile Telephone System
1 G Mobile Phone
Analog voice
2 Generation Mobile Phone
2.5 G
3 G
Reference: Wikepedia, the free encyclopedia,
January 16, 2007

11. 1st Generation Cellular Phone System
Advanced Mobile Phone Service (AMPS)
Invented by Bells Labs and first installed in the U.S. in 1982
Analog FDMA (Frequency Division Multiple Access)
ISM 800-MHz band
Base Station → Mobile Station: forward communication channels ( MHz: 25 MHz band)
Base Station ← Mobile Station: reverse communication channels ( MHz: 25 MHz band)
Voice channel – Frequency modulation (30 kHz)
Control Channels - FSK (Frequency Shift Keying) – 10 kbps/30 kHz signal
No of Channels
832 channels: 25 MHz / 30 kHz, can be shared by two providers
Each provider: 416 channels in each cell , 21 channels for control, 395 channels for voice
Frequency Reuse Factor
Reuse factor 7
1/7 of 395 traffic channels are available in a cell
In England – TACS
In Japan – MCS-L1
January 16, 2007

12. 1st Generation Cellular Phone System
Invented by Bells Labs and first installed in the U.S. in 1982
Analog FDMA (Frequency Division Multiple Access)
ISM 800-MHz band
Base Station → Mobile Station: forward communication channels ( MHz: 25 MHz band)
Base Station ← Mobile Station: reverse communication channels ( MHz: 25 MHz band)
Voice channel – 30 kHz subband, Frequency modulation
Control Channels - FSK (Frequency Shift Keying) – 10 kbps/30 kHz signal
No of Channels
832 channels: 25 MHz / 30 kHz, can be shared by two providers
Each provider: 416 channels in each cell , 21 channels for control, 395 channels for voice
Frequency Reuse Factor
Reuse factor 7
1/7 of 395 traffic channels are available in a cell
In England – TACS
In Japan – MCS-L1
January 16, 2007

13. 2nd Generation Cellular Telephone System
D-AMPS (Digital AMPS)
IS-136
TDMA-FDMA
GMS (Global System for Mobile Communication)
IS-95 CDMA (Code Division Multiple Access)
CDMA-FDMA
January 16, 2007

14. Digital Advanced Mobile Telephone System (D-AMTS)
Cells – geographic regions
AMPS Cells – 10 to 20 km across
D-AMPS Cells – Smaller
Each cell uses some set of frequencies not used by any of its neighbors
January 16, 2007

15. D-AMPS D-AMPS (Digital AMPS) Backward compatible with AMPS: FDMA
IS-54 (Interim standard 54)
TDMA (Time Division Multiple Acceess)/IS-136
Added to each sub-band
Triple the no. of channels
ISM 800 MHz band
MHz range: Base station → Cellular phone (forward channels)
MHz range: Cellular phone →Base station (reverse channels)
January 16, 2007

16. Voice Signal Digitization
D-AMPS (continue)
Voice Signal Digitization
Digitizing: PCM (Pulse Code Modulation) and compression
3 kHz → PCM Digitized →7.95 kbps digital voice channel
TDMA
1 slot – 7.95 kbps
3 slots: 48.6 kbps digital data: 3 x 7.95 kbps
Combined using TDMA
TDMA Frame [ ]
January 16, 2007

17. D-AMPS (continue) Digitized Voice Signal Transmission
25 frames per second
1944 bits per frame
Each frame last 40 ms (1/25) and is divided into 6 slots shared by three digital channels: TDMA [ ]
Each channel: 2 slots
324 bits per slot: 159 bits digitized voice, 64-bits control, 101-bits for error correction
QPSK Modulation (Quadrature Phase-Shift Keying)
48.6 kbps → QPSK Modulation → 30 kHz analog signal
FDMA
25 MHz band, 30 kHz analog signal
Reuse Factor 7
January 16, 2007

18. GMS (Global System for Mobile Communication)
Digital mobile telephony system launched in Finland in 1991
TDMA, Digitize and compress data
900 MHz or 1800 MHz frequency band
SIM cards (Subscriber Identity Module)
Capture 82.4% of all global mobile connection
Widely used in Europe and Asia
January 16, 2007

19. GMS (continue) Bands Transmission Reuse Factor 3 25 MHz band
124 Channels of 200 kHz separated by guard bands
Transmission
Voice channel → Digitize + Compress → 13-kbps digital signal
1 slot = bit
1 Frame (TDMA) = 8 slots; frame duration 120 ms
A Multi-frame = 26 frames (TDMA) = kbps
26 frames = 24 traffic frames + 2 control frames
270.8 kbps → GMSK → 200 kHz signal (FDMA)
Reuse Factor 3
January 16, 2007

20. IS-95 CDMA
Based on CDMA (Code Division Multiple Access) and DSSS (Direct Sequence Spread Spectrum)
Wireless Communications, Chapter Network Concepts and Standards, IS95 CDMA Cellular Telephony, Springer,
Bands and Channels
Duplex using two bands
ISM 800-MHz or ISM 900-MHz
20 Channels of MHz, guard bands
10 channels for each provider
Can be used in parallel with AMPS
1 IS-95 Channel = 41 AMPS channels (41 x 30 kHz = 1.23 MHz)
January 16, 2007

21. IS-95 CDMA (cont.) Base Channel Synchronization
Base stations use GPS (Global Positioning System)
Forward Transmission (base to mobile)
64 Digital Channels (3 kHz each)
Voice 3 kHz → 9.6 kbps → Error-correcting & repeating bits → 19.2 kbps
Scrambling signal: ESN (Electronic Serial No of mobile station) pseudo random chip → Decimator (1 out of 64 bits)
64 channels x 64 Walsh code → CDMA
1.228 Mcps (Megachips per second) = 19.2 kbps * 64 cps
QPSK → MHz
25MHz Band: 20 Channels FDMA
Channel 0: Pilot Channel, sends [1, 1, 1, 1, …] for bit sync
Ch 1 – 7: paging, send messages to one or more mobile devices
Ch 8–31 and 33-63: voice traffic channels
Ch 32: give info about the system
January 16, 2007

22. IS-95 CDMA (cont.) Reverse Transmission (Mobile to Base)
3 kHz Voice → Digitizer → 9.6 kbps → Error correcting & repetition → 28.8 kbps → 6-symbol chuck, 0-64, Symbol Modification → kbps = (28.8/6) x 64
ESN → Long Code Generator 42-bit → Mcps
DSSS (Direct Sequence Spread Spectrum)
94 Channels
62 Traffic channels
32 Base station access control channels
1.28 Mcps → QPSK → MHz
FDMA 20 channel x MHz = 25 MHz
January 16, 2007

23. Frequency Reuse Factor
IS-95 CDMA (cont.)
Two Data Rate Sets
Frequency Reuse Factor
Interference from neighboring cells
Reuse factor 1
Soft Handoff
Every base station → Pilot channel broadcast
Enable a mobile station to do a soft handoff
January 16, 2007

24. Signal Modulation Techniques
Mobile Communication Infrastructures
1G Analog FM (Carrier modulation), FDMA (Frequency Division Multiple Access)
2G TDMA (Time Division Multiple Access) + FDMA
Digital Wireless Transmission Techniques
Impulse transmission
Infrared Pulse Transmission
UWB (Ultra Wideband), impulse radio
TDMA Cellular
CDMA (Code Division Multiple Access) - Spread Spectrum
January 16, 2007

25. Signal Modulation Techniques (cont.)
Analog Modulation
Frequency Modulation (FM)
Digital Frequency Modulation
Digital (0, 1) FM – Frequency Shift Keying (FSK)
GMSK (Guaussian Minimum Shift Keying)
FSK modulation with minimal tone distance of 1/2T; T – the duration of transmitted data symbols
Data In → Gaussian Filter → FM modulator
Adopted by GMS
January 16, 2007

26. Signal Modulation Techniques (cont.)
Digital Phase Modulation (PSK)
B-PSK (Binary Phase Modulation)
[0, 1] – (cos2π fc t + 0º), (cos2π fc t + 180º)
January 16, 2007

27. Signal Modulation Techniques (cont.)
Digital Phase Modulation (PSK)
QPSK (Quadrature PSK, 4 Phases)
11 – (cos2π fc t + 45º)
01 - (cos2π fc t + 135º)
00 – (cos2π fc t + 225º) or (cos2π fc t -135º)
11 - (cos2π fc t + 315º) or (cos2π fc t - 45º)
January 16, 2007

28. Signal Modulation Techniques (cont.)
π/4-QPSK – adopted by the North American TDMA digital cellular standard, IS-136
Two identical constellation – rotated by 45º or π/4 radians
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29. Frequency Reuse Factor 4
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30. Frequency Reuse Factor 7
January 16, 2007

31. SIMO and MIMO Channels
SIMO (Single Input Multiple Output) Radio Channel
Complex receiver with adaptive smart antenna with M antenna elements
MIMO (Multiple Input Multiple Output) Radio Channel
N mobile antenna elements
M base station antenna elements
January 16, 2007

32. 3rd Generation Technologies
A Combination of Technologies
Audio and Video
VoIP
Still & Moving Images
Digital Data
UTMS (Unified Mobile Telephone Service)
Enhanced multimedia: movie, images, music Internet Surfing
Video telephony, Video conferencing
Always connected infrastructure
January 16, 2007

33. 3rd Generation Technologies
IMT-2000 (Internet Mobile Communication 2000)
Voice quality (public telephone network)
Data rate
144 kbps for access in a moving vehicle
384 kbps for access as the user walks
2 Mbps for stationary user (office or home)
Support packet-switched and circuit-switched data services
2 GHz band
2 MHz Bandwidth
Interface to Internet
January 16, 2007

34. 3rd Generation Technologies
IMT-2000 Radio Interface
IMT-DS (Direct Sequence): CDMA
Wideband spread-spectrum, direct sequence CDMA
Compatible with the CDMA used in IS-95
IMT-MC (Multi-carrier): CDMA
CDMA 2000
New wideband (15-MHz) Spread Spectrum with narrow band (1.25 MHz) CDMA of I-95
IMT-TC (Time Code): CDMA & TDMA
IMT-SC (Single Carrier): TDMA
IMT-FT (Frequency time): TDMA & FDMA
CDMA2000
Code Division Multiple Access
Pioneered by Qualcomm
January 16, 2007