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Kyung Hee University
Chapter 17Chapter 17Cellular Telephone and Satellite Cellular Telephone and Satellite
NetworksNetworks
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17.1 Cellular Telephony17.1 Cellular Telephony
Frequency Reuse Principle Transmitting Receiving Handoff Roaming First Generation Second Generation
Third Generation
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Cellular SystemCellular System
A cellular service area is divided into cells.
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First GenerationFirst Generation
AMPS (Advanced Mobile Phone System) is an analog c
ellular phone system using FDMA
operating in the ISM 800 Mhz
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Second-generation cellular phone systemsSecond-generation cellular phone systems
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D-AMPSD-AMPS
D-AMPS, or IS-136, is a digital cellular phone system using TDMA and FDMA.
• A second-generation cellular phone system that is a digital version of AMPS
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GSMGSM
Global System for Mobile Communication (GSM) is a
second-generation cellular phone system used in
Europe
bands
= =
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Multiframe ComponentsMultiframe Components
GSM is a digital cellular phone system using TDMA and FDMA.
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IS-95IS-95
Interim Standard 95 is a second-generation cellular
phone system based on CDMA and DSSS
IS-95 forward transmission
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IS-95 reverse transmissionIS-95 reverse transmission
IS-95 is a digital cellular phone system using CDMA/DSSS and FDMA.
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Third GenerationThird Generation
The main goal of third-generation cellular telephony is
to provide universal personal communication.
Internet Mobile Communication for year 2000 (IMT-2000)
IMT-2000 radio interfaces
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17.2 Satellite Networks17.2 Satellite Networks
• Orbits
• Three Categories of Satellites
• GEO Satellites
• MEO Satellites
• LEO Satellites
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ExamplesExamples
Example 1Example 1
What is the period of the moon according to Kepler’s What is the period of the moon according to Kepler’s law?law?
SolutionSolution
The moon is located approximately 384,000 km above the earth. The radius of the earth is 6378 km. Applying the formula, we getPeriod = (1/100) (384,000 + 6378)1.5 = 2,439,090 s = 1 month
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ExamplesExamplesExample 2Example 2
According to Kepler’s law, what is the period of a satAccording to Kepler’s law, what is the period of a satellite that is located at an orbit approximately 35,78ellite that is located at an orbit approximately 35,786 km above the earth?6 km above the earth?
SolutionSolution
Applying the formula, we get
Period = (1/100) (35,786 + 6378)1.5 = 86,579 s = 24 h
A satellite like this is said to be stationary to the earth. The orbit, as we will see, is called a geosynchronous orbit.
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Satellite frequency bandSatellite frequency band
Band Band Downlink, GHzDownlink, GHz Uplink, GHzUplink, GHz Bandwidth, MHzBandwidth, MHz
LL 1.51.5 1.61.6 1515
SS 1.91.9 2.22.2 7070
CC 44 66 500500
KuKu 1111 1414 500500
KaKa 2020 3030 35003500
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GPSGPS
24 satellites in six orbits.
Medium-Earth-orbit (MEO) satellites that provide time
and location information for vehicles and ships.
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LEO (Lowor-Earth Orbit) SatellitesLEO (Lowor-Earth Orbit) Satellites
UML : User Mobile Link, GWL : Gateway Link, ISL : Intersatellite Link
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Iridum Constellation Iridum Constellation
The Iridium system has 66 satellites in six LEO orbits, each at an altitude of 750 km.
Providing direct universal voice and data communications for handheld terminals.
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TeledesicTeledesic
• Teledesic has 288 satellites in 12 LEO orbits, each at an altitude of 1350 km.
• Teledesic satellites are low-Earth-orbit satellites that will provide universal
broadband Internet access.