Unit 12

Question 1

ad-hoc network

Answer 1

A network with dynamic routing and without dedicated nodes like routers and hubs, thereby allowing nodes to easily join and leave the network.

Question 2

application portability

Answer 2

The ability to adapt an application to a different platform. The easier the adaptation is, the more portable the application is said to be.

Question 3

cell (of a transceiver)

Answer 3

The area that a transceiver covers.

Question 4

code on demand

Answer 4

On a request from the client, code is transferred from the server and executed on the client, using the client’s resources.

Question 5

context awareness

Answer 5

The ability for hardware to detect the current environment and for software to adapt to it.

Question 6

geotagged information

Answer 6

Data that has been associated to a physical location, e.g. the address of a restaurant is geotagged with the latitude and longitude of its location.

Question 7

Global Positioning System (GPS)

Answer 7

A satellite system that sends continuous radio signals, thereby enabling a receiver on the Earth to compute its latitude and longitude.

Question 8

latency

Answer 8

In general, the delay between the time an activity is initiated and the time its effects are noticed. In the concrete case of networks, it is the time taken for messages to be transmitted from one host to another.

Question 9

logical mobility

Answer 9

The change of host of a software component.

Question 10

mobile agent

Answer 10

An execution unit that moves, together with some code and resources, from one site to another, where it resumes execution.

Question 11

mobile code

Answer 11

Code that is transferred from one execution unit to another, where it is executed.

Question 12

mobile computing

Answer 12

The use of a portable computer with a wireless network connection.

Question 13

Mobile IP

Answer 13

A standard internet protocol for communicating with mobile nodes.

Question 14

personal area network

Answer 14

A short-range network connecting various devices, typically for personal use, with each other; for example, a network connecting home entertainment devices, a personal computer and a mobile phone.

Question 15

physical mobility

Answer 15

The change of physical location of a hardware component.

Question 16

physical portability

Answer 16

The ability to easily carry and move a computing device from one physical location to another.

Question 17

portability

Answer 17

In the context of mobile systems, this means physical portability. In the context of software development, it means application portability.

Question 18

radio-frequency identification (RFID)

Answer 18

A radio-based technology to communicate with small devices that can store and change small amounts of data.

Question 19

remote evaluation

Answer 19

The transfer of code from the client to the server, where it is executed using local resources, after which a reply is sent to the client.

Question 20

strong mobility

Answer 20

The ability, provided by the platform or middleware, to suspend an execution unit, capture its state (including the code it is executing and the data it is manipulating) and transfer all this to a new site, where execution is resumed.

Question 21

transceiver

Answer 21

A transmitter and receiver of radio wave signals.

Question 22

weak mobility

Answer 22

The ability, provided by the platform or middleware, to transfer code from one site to another.