Chapter 16 Questions

Explain the differences between a fixed WiMAX and a mobile WiMAX.

A mobile WiMAX has mobile stations and a base station. All stations in a fixed WiMAX are stationary.

What is AMPS?

Advanced Mobile Phone System, analog cell system using FDMA, 1G

What is the relationship between a base station and a mobile switching center?

Base stations pass info from their cells to the MSC which networks the info to the central cell center and other base stations.

What is the function of the CDMA in IS-95?

CDMA encodes each traffic channel using one of the rows in the walsh 64 table

What are the functions of a mobile switching center?

Communicates between base stations and central office. Responsible for billing.

What is the relationship between D-AMPS and AMPS?

D-AMPS is digital, AMPS is analog

What are the three types of orbits?

Equatorial, Inclined, Polar

Which type of orbit does a GEO satellite have? Explain your answer.

Equatorial, needs to move at the same speed as the Earth's rotation for line-of-sight propagation.

When we make a wireless Internet connection from our desktop at home, do we use fixed or mobile WiMAX?

Fixed

What is GSM?

Global System for Mobile Communication, European version of D-AMPS

What is the difference between a hard handoff and a soft handoff?

Hard handoffs occur when the mobile station can only connect to one base station at a time. This means the mobile station must completely disconnect from the previous base station before connecting to the new station. Soft handoffs became possible when mobile stations became able to connect to multiple base stations at once. Therefore, the mobile station can connect to the next base station before disconnecting from the previous base station meaning service is never lost.

Which is better, a low reuse factor or a high reuse factor? Explain your answer.

High reuse is better so frequencies can be reused more often.

What is the main difference between Iridium and Globalstar?

Iridium only requires satellites, Globalstar requires satellites and ground stations

When we make a wireless Internet connection from our cellular phone, do we use fixed or mobile WiMAX?

Mobile

What is a footprint?

The area a satellite services

What is the purpose of GPS?

To track location and give directions

Compare an uplink with a downlink.

Uplink = sending data to a satellite Downlink = receiving data from a satellite

What is the relationship between the Van Allen belts and satellites?

Van Allen belts are the two layers of high energy charged particles in the sky. Satellites aren't in these belts to avoid effects on signals.

To which generation does each of the following cellular telephony systems belong? a.) AMPS b.) D-AMPS c.) IS-95

a.) 1G 2.) 2G 3.) 2G