1.1 COMPUTER COMMUNICATIONS CATEGORIES

 

• Basic Categories

• Interface to Sensors and Actuators

- Uses readings from sensors to control devices in the environment

- very simple protocols, but often requires specialized hardware and software.

• Interface to computers

- uses machine to machine connection for direct communication

- can appear to be like a local area network

- low speeds (eg. 300 baud, 1.2, 2.4 9.2 Kbaud)

• Local Area Computer Networks

- measured in distances from meters to kilometers

- speed measured in Megabits/sec

- medium includes, wire, fibre-optics, radio frequency

- commonly available in all forms

- inexpensive

• Wide Area Computer Networks

- from city wide, to global

- speed measured in Kilobytes/second

- medium includes, wire, fibre optics, satellite, microwave

- access is costly (some mix of initial and variable costs), and geared to large corporations, or special applications.

 

• Classification of Interconnected processors (by Physical Size)

Table 1:

Inter-processor Distance

Processors Located in Same

Example

0.1 m

Circuit Board

Data flow machine

1 m

System

Multi-

processor

10 m

Room

Local

network

100 m

Building

1 km

Campus

10 km

City

Long haul network

100 km

Country

1000 km

Continent

Inter-

connection of long haul networks

10000 km

Planet

 

 

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