Lucent Technologies Proprietary 1

Wireless Telephony

Walter Amos

Technical Manager

Rufus Austin

Technical Manager

Lucent Technologies Proprietary 2

Objectives

• Evolution of Cellular Technology

• Cellular Standards

• Wireless Networks

• Wireless Vision

• Technical Degree mapping to R&D Careers

Lucent Technologies Proprietary 3

1930/40’s FM used for mobile radio

1946 First commercial mobile telephone introduced in St. Louis

1947 AT&T proposed mobile telephone systems based on cell concept

1920’s First mobile radio units installed in Police cars in Detroit/NYC

1964 Mobile Telephone Service (MTS) introduced Automatic Dialing

1950’s 11channels VHF 12 channels UHF

–Full scale cellular system to prove 1969 concept –FCC had previously approved 800 MHz operation

1975 AT&T application for Chicago Trial

1983 First Commercial cellular service in Chicago

1920 1930 1940 1950 1960 1970 1980 1990

Early History of Mobile Communications

UHF = Ultra High Frequency 300MHz - 3GHz

VHF = Very High Frequency 30MHz - 300MHz

Lucent Technologies Proprietary 4

Early Problems

• Small service area 20-25 miles

• High blocking rates due to low number of channels

• Long wait list for service

• Poor voice quality

• Users could listen to each other’s calls

Lucent Technologies Proprietary 5

Wireless Telephonyand Interim Standards

• AMPS (Advanced Mobile Phone System)– IS553

• NAMPS (Narrow Band Amps)– IS88

• TDMA (Time Division Multiple Access)– IS54

• CDMA (Code Division Multiple Access)– IS95

Lucent Technologies Proprietary 6

Network Wireless Systems Proprietary Lucent TechnologiesBell Labs Innovations

CordlessPhone Receiver

Line

Different Types of Phone Connections

412

Trunk

Mobile SwitchingCenter (MSC)

Cell Trunks

LandlinePhone

Switching Office

Network

Switching Office

Trunk Trunk

Phone

Line

Line

WirelessPhone

Lucent Technologies Proprietary 7

Cellular System Architecture

SwitchingOffice

Cell Site

Cell Site

Trunks

Data LinksMSC

Residential

2nd Line

BaseStation

BaseStation

Lucent Technologies Proprietary 8

Analog Cellular

• Analog Cellular sets up a call on each 30 kHz Channel

30 kHz Channel

Lucent Technologies Proprietary 9

Dual-Mode Capability

3x the capacity of analog networks

30 kHz Channel Spacing

832 Channels

8 kbps (Full Rate Mobiles)

6 time slots per channel

2 time slots per mobile

uplink Tx

downlink Rx

3 calls per channel

TDMA

Time Slot 1 Time Slot 2

Time Slot 3

Time Slot 4

Time Slot 5 Time Slot 6

Time Slot 1 Time Slot 2 Time Slot 3 Time Slot 4 Time Slot 5 Time Slot 6

30 kHz Channel

Lucent Technologies Proprietary 10

TDMA 4 Kbps (Half Rate Mobiles)

6 time slots per channel

1 time slots per mobile– handles both uplink Tx/ downlink Rx

6 calls per channel

30 kHz Channel

Time Slot 1 Time Slot 2 Time Slot 3 Time Slot 4 Time Slot 5 Time Slot 6

Lucent Technologies Proprietary 11

Advantages of CDMA

• Spread Spectrum Analysis• 1.23 MHz channel vs. 30 kHz• Each call is distinguished by a unique digital code

different from others users transmitting at the same frequency band

• >= 10 times the capacity of analog networks• Lower Power Terminals/Longer Battery Life

Lucent Technologies Proprietary 12

Service Provider Benefits

• 10x capacity of analog networks

• Broader Coverage Area

• All frequencies can be used in each cell

• SMS services

• Excellent Call Quality• Multiple Technology

Support• Data Services

– Packet Data = PC/Cell Phone access to Internet

– Circuit Mode = Fax through PC/Cell Phone

Lucent Technologies Proprietary 13

End User Benefits

• Soft Handoffs – no call degradation

during handoff

• Longer Battery Life– Power control varied to

match strongest cell

• Inherent Privacy– Built in Encryption

• No I/F with hearing aids/pacemakers

• Integrated Data/Voice– SMS

• Low Power Mobiles– ~10db less power Tx

than AMPS/TDMA

Lucent Technologies Proprietary 14

Network Wireless Systems Proprietary Lucent TechnologiesBell Labs Innovations

Air Interfaces and Efficiencies

FDMAFREQUENCY Division

Multiple Access

TDMATIME DivisionMultiple Access

CDMACODE DivisionMultiple Access

Classification:

Reuse Factor:

Carrier Bandwidth:

Calls per Carrier:

Analog

7

30 Khz

1

Digital

7

30 Khz

3

Digital

1

1.25 MHz

13 - 28+

1432

Lucent Technologies Proprietary 15

1. Mobile registers itself

Cellular Networking and (IS41) Roaming

HomeSystemMSC

SS7 Links STPSTP

VLRHLR

2. Visiting system requests DB info about subscriber

5. The subscriber receives 1 phone bill from home system

VisitorSystemMSC

1

3. Home system forwards the call to the visiting system

Voice Network4. Home system kept informed of mobile position

Lucent Technologies Proprietary 16

MSC - Mobile Switching CenterBS - Base Station

Intelligent Network

(SCP, SCE, SMS, SCN, HLR, etc.)

IS95: 0,A,JTAIS53 / IS104IS99

Vendor Interconnectivity

PSTN

IS41-A, B, or CINAP: 0.1, 0.2WIN: IS41C

Feature Group D(Equal Access)

ISUP, R1 MF, DTMF

STP

BaseStation

Other VendorPCS MSC

MSC

IS41-C

MessageCenter

ServiceNode

ISUP, PRI, BRI

VoiceMail

R1 MF, DTMF

IS41-C

Outside Vendor Products

Other Cellular Systemsand/or Networks

IS41-A, B, or C

IS634

Lucent Technologies Proprietary 17

National Interconnectivity

PCS

PCS

CellularPCS

PCSCellular

Cellular

Cellular

CellularCellular Cellular

Cellular

PCSCellular

SS7 Signaling NetworkCTIA, Mobilink, or New

(IS41 A, B, and C)

Seamless Automatic Roaming• Registration /

Authentication• Call Delivery• Handoff

System Operations• Billing (Clearing

House)• Roaming

Agreements• Over-the-Air

Distribution

Lucent Technologies Proprietary 18

Private Networks/User Zones

Blue PrivateNetwork

In-Building

Public Network(Green)

Red PrivateNetwork

(Campus Area)

Red Virtual Private Network

Includes All

Lucent Technologies Proprietary 19

Classroom to the Board Room

• Engineering

• Computer Science

• Product/Project Management

• Systems Engineer

• Software/Hardware Engineer

• RF Engineer

• Panel/Physical Designer

• Test Engineer

• Application Engineer

• Field Engineer