Cellular and Personal Communications Systems

1
Cellular and Personal Communications Systems
2
Chapter Thirty Three Objectives

• Describe how cellular communications works
• Describe the differences between analog and
  digital cellular
• Describe the call setup process
• Explain the pieces that make up a cellular
  network
• Define the concept of PCS

3
Cellular and PCS

• IMTS coverage areas and frequency reuse

4
Cellular and PCS

• A call in progress handled by the cell

5
Cellular and PCS

• Cell site senses the drop in signal and alters
  the MTSO

6
Cellular and PCS

• MTSO begins to prepare for handoff

7
Cellular and PCS

• Cell site advised to go to new channel

8
Cellular and PCS

• Cellular pattern of overlapping cells

9
Cellular and PCS

• Cellular equipment now links to the backbone
  network through SS7 linkage

10
Cellular and PCS

• The cellular (mobile) unit sets up the calls to
  the cell site (base station) using a
  frequency-agile capacity to synthesize the
  necessary frequency

11
Cellular and PCS

• Cellulars Success and Loss
• High cost of the service
• Possibility of getting poor transmission or
  reception on the network
• Lack of available service
• Carrier problems
• Accommodate more users
• Sell more price-sensitive services
• Generate new revenue
• Get more subscribers to generate more revenue to
  pay off the high investment

12
Cellular and PCS

• Cell splitting
• Required when constant congestion occurs
• Helps use (reuse) more frequencies in smaller
  (coverage) areas

13
Cellular and PCS

• Problems with cell splitting

14
Cellular and PCS

• The set was taken out of the car. Battery
  technology determines the standby and operation
  time.

15
Cellular and PCS Digital Transmission
16
Cellular and PCS Fax Technology

• Post-fax scenario

17
Cellular and PCS

• Interruptions on the circuit do not cause
  disconnections. A line of dots may be lost in
  handoff.

18
Cellular and PCS

• Many disconnects with early wireless data

19
Cellular and PCS

• Improvements in data communications prevent
  disconnections as handoff occurs

20
Cellular and PCS Digital Evolution

• TDMA
• CDMA
• PCS

21
Cellular and PCS

• Comparison of technologies considered for PCS/PCN

22
Cellular and PCS/PCN

• A charger smart box enables standard cordless
  performance when used with telco wires

23
Cellular and PCS/PCN

• The communicator is connected to the telco via
  microcell technology

24
Cellular and PCS/PCN

• Spring loaded wrist phone

25
Cellular and PCS

• After removing the set from the smart box and
  leaving the locale, an instant communication is
  established via microcell to alert the network
  that the user is mobile

26
Cellular and PCS

• Telepoints can be mounted on the sides of
  buildings

27
Cellular and PCS/PCN

• Microcells can be mounted on the tops of buildings

28
Cellular and PCS/PCN

• Notes