Mobile Computing

Question 1

(2 answers)

What are the motivations for mobile computing?

Answer 1

• More convenient
• Allows access to computing facilities or telecommunication from a very wide range of locations

Question 2

(2 answers)

What are the advantages of mobile computing?

Answer 2

• Users can communicate and access other parts of a distributed system from a wider variety of locations
• Wireless mobile systems avoid the cost and disruption of fixed wiring installation

Question 3

(2 answers)

What are the disadvantages to mobile computing?

Answer 3

• Increased security risks - mobile devices are more likely to be lost or stolen, and wireless communications are more vulnerable to interception
• Performance - wireless communications are typically slower, have less capacity, and are less reliable

Question 4

(2 answers)

How can the security risks involved with mobile computing be minimised?

Answer 4

• Requiring passwords to establish a connection
• Encrypting all communication with stream ciphers

Question 5

(8 answers)

What are the fallacies of distributed computing?

Answer 5

• The network is reliable
• Latency is zero
• Bandwidth is infinite
• The network is secure
• Topology does not change
• There is one administrator
• Transport cost is zero
• The network is homogeneous

Question 6

What are mobile components?

Answer 6

Mobile components are not fixed in any one location.

Communication often takes place wirelessly, though this is not a requirement.

Question 7

What is physical mobility?

Answer 7

Hardware components moving around the physical space.

Question 8

What is physical portability?

Answer 8

Physical portability is the ability to move the device from one physical space to another.

Question 9

What is logical mobility?

Answer 9

Software components moving across (possibly fixed) hosts.

Question 10

What is code mobility?

Answer 10

Code mobility is the ability for code to be transferred to, and then executed on, a different device.

(e.g. applets)

Question 11

What is a mobile agent?

Answer 11

Code begins execution on one device and can be suspended and transferred to another device, where execution is resumed.

Question 12

What is strong mobility?

Answer 12

Strong mobility is the ability to suspend, transmit, then resume code on another device.

(e.g. mobile agent)

Question 13

What is weak mobility?

Answer 13

Weak mobility is the ability to only move code between devices.

Question 14

(Ubiquitous = omnipresent, everywhere, etc)

What is ubiquitous computing?

Answer 14

Ubiquitous computing is a world in which small, highly portable computing devices are everywhere in our environment and integrated with everyday life.