Networking and

communication basics.

Areej Aloufi

Basic Concepts in Communication

Basic Concepts

Communications – activity associated with distributing or Communications – activity associated with distributing or exchanging informationexchanging information

Telecommunications – technology of communications at a distance Telecommunications – technology of communications at a distance that permits information to be created any where and used that permits information to be created any where and used everywhere with little delayeverywhere with little delay

Today it, involves Today it, involves

Data: digital and analogData: digital and analog

Voice: spoken wordVoice: spoken word

Video: telelcommunication imagingVideo: telelcommunication imaging

Essentials for Communications

Essentials for Communications

Essentials for Communications

Source Transmitter Transmission Receiver Destination

1 2 3 4 5 6

Understanding Networking

Big Picture

Key Network Terminology Explained (1)

Networks needs to interconnect at a distance by a form of Networks needs to interconnect at a distance by a form of point to point or point to multiple point connected mediapoint to point or point to multiple point connected media

A network is a group of computers connected together in A network is a group of computers connected together in such a way as to allow such a way as to allow

Networks that are interconnected have proven to be low Networks that are interconnected have proven to be low cost, reliable, and efficient means of communicating at a cost, reliable, and efficient means of communicating at a distancedistance

Key Network Terminology Explained (2)

Node: anything connected to the network, usually a Node: anything connected to the network, usually a computer, but it could be a printer or a scannercomputer, but it could be a printer or a scanner

Segment: any portion of a network that is separated by a Segment: any portion of a network that is separated by a switch, bridge or a router from another part of a network.switch, bridge or a router from another part of a network.

Backbone: the main cabling of a network that all of the Backbone: the main cabling of a network that all of the segment connect to. Usually, the backbone is capable of segment connect to. Usually, the backbone is capable of carrying more information than the individual segments. carrying more information than the individual segments.

Topology: The way each node is physically connected to Topology: The way each node is physically connected to the networkthe network

Networkarchitecture

Common Topologies - Bus Bus: each node is daisy-chained Bus: each node is daisy-chained (connected one right after the (connected one right after the other) along the same backbone. other) along the same backbone. Information sent from a node Information sent from a node travels along the backbone until it travels along the backbone until it reaches its destination node. reaches its destination node.

Common Topologies - RingRing: Similar to a bus network, rings have nodes daisy chained, but the end of the network in a ring topology comes back around to the first node, creating a complete circuit.

Common Topologies - StarIn a star network, each node In a star network, each node is connected to a central is connected to a central device called a hub. The hub device called a hub. The hub takes a signal that comes takes a signal that comes from any node and passes it from any node and passes it along to all the other nodes in along to all the other nodes in the network. the network.

Key Network Terminology Explained (3)

Simplex: information flows in only one directionSimplex: information flows in only one direction

Half-duplex: information flows in two directions, but Half-duplex: information flows in two directions, but only in one direction at a time.only in one direction at a time.

Full-duplex: information flows in two directions at the Full-duplex: information flows in two directions at the same timesame time

Data TransmissionSuccessful transmission of data depends on:Successful transmission of data depends on:

The quality of the signal being transmittedThe quality of the signal being transmitted

Characteristics of the transmission mediumCharacteristics of the transmission medium

Data rate – bits per second in data communicationsData rate – bits per second in data communications

Bandwidth – bandwidth or signal is constrained by the transmitter and the Bandwidth – bandwidth or signal is constrained by the transmitter and the nature of the transmission in cycles per second or hertznature of the transmission in cycles per second or hertz

Noise – Average level of noise over the communication path.Noise – Average level of noise over the communication path.

Error rate – rate at which errors occur where error in 1 or 0 bit occursError rate – rate at which errors occur where error in 1 or 0 bit occurs

Understanding Transmission Medium

Basic transmission medium concepts

Medium is the physical path between transmitter Medium is the physical path between transmitter and receiver in a data transmission systemand receiver in a data transmission system

Guided Medium: waves are guided along a solid Guided Medium: waves are guided along a solid medium path medium path ..

Unguided medium: waves are propagated through Unguided medium: waves are propagated through the atmosphere and inner/outerspace (satellite, the atmosphere and inner/outerspace (satellite, laser, and wireless transmissions).laser, and wireless transmissions).

Medium examples by type

Conductive: twisted pairs and coaxial cablesConductive: twisted pairs and coaxial cables

Electromagnetic: microwaveElectromagnetic: microwave

Light: lasers and optical fibers (need clear line of Light: lasers and optical fibers (need clear line of sight)sight)

Wireless – inner/outerspace; satelliteWireless – inner/outerspace; satellite

Network Hardware

What is the difference between?

Bridge: device to interconnect two LANs that use the Bridge: device to interconnect two LANs that use the SAME logical link control protocol but may use SAME logical link control protocol but may use different medium access control protocols.different medium access control protocols.

Router: device to interconnect SIMILAR networks, Router: device to interconnect SIMILAR networks, e.g. similar protocols and workstations and serverse.g. similar protocols and workstations and servers

Gateway: device to interconnect DISSIMILAR Gateway: device to interconnect DISSIMILAR protocols and servers, and Macintosh and IBM LANs protocols and servers, and Macintosh and IBM LANs and equipmentand equipment

Switches

Allow different nodes of a network to communicate Allow different nodes of a network to communicate directly with each other.directly with each other.

Allow several users to send information over a Allow several users to send information over a network at the same time without slowing each network at the same time without slowing each other down.other down.

WANs and LANs

Major Categories of Networks

Local Area Networks (LAN)Local Area Networks (LAN)

A network of computers that are in the same general A network of computers that are in the same general physical location, within a building or a campus. physical location, within a building or a campus.

Metropolitan Area Networks (MAN)Metropolitan Area Networks (MAN)

Wide Area Networks (WAN)Wide Area Networks (WAN)

What is ethernet?

A group of standards for defining a local area A group of standards for defining a local area network that includes standards in cabling and the network that includes standards in cabling and the structure of the data sent over those cables as well structure of the data sent over those cables as well as the hardware that connects those cables.as the hardware that connects those cables.

Independent of the network architectureIndependent of the network architecture

How does Ethernet work?

Using addresses to distinguish between machines, Using addresses to distinguish between machines, Ethernet transmits frames of data across baseband Ethernet transmits frames of data across baseband cablescables..

Communication protocol standards:

Connectivity:Connectivity: refers to a measure of the effectiveness and refers to a measure of the effectiveness and efficiency of computer based devices to communicate and efficiency of computer based devices to communicate and share information and messages without human share information and messages without human intervention. It is achieved by the use of communication intervention. It is achieved by the use of communication protocol standards.protocol standards.

Protocols:Protocols: deals with the specifics of how a certain task deals with the specifics of how a certain task will be done. will be done.

Standard:Standard: it is an approved reference model and protocol it is an approved reference model and protocol determined by standard setting groups for building or determined by standard setting groups for building or developing products and services.developing products and services.

Communication protocol standards:

HIS, RIS and PACs are integrated using HIS, RIS and PACs are integrated using communication protocol standards. The two popular communication protocol standards. The two popular standards are health level 7 (HL-7) and digital standards are health level 7 (HL-7) and digital imaging and communication in medicine (DICOM).imaging and communication in medicine (DICOM).

Communication protocol standards:

HL-7 : standard application protocol most used with HL-7 : standard application protocol most used with HIS and RIS.HIS and RIS.

DICOM : is the imaging communication protocol for DICOM : is the imaging communication protocol for PACs. PACs.

Computer in radiology:

In 1955 computers were used to calculate radiation In 1955 computers were used to calculate radiation dose distributions in cancer patients. Today, dose distributions in cancer patients. Today, computer applications in radiology include two computer applications in radiology include two categories imaging and nonimaging applications. categories imaging and nonimaging applications.

Imaging applications:

They are those modalities in which the information They are those modalities in which the information acquired from the patient is subjected to computer acquired from the patient is subjected to computer processing. This involves digital image processing processing. This involves digital image processing techniques to produce computer – generated or techniques to produce computer – generated or digital images. These images can be stored or digital images. These images can be stored or displayed.displayed.

Several methods exist for creating images: Several methods exist for creating images: computed radiography, digital fluroscopy, computed radiography, digital fluroscopy, radiographic film digitalization computed radiographic film digitalization computed tomography and magnetic resonance imaging.tomography and magnetic resonance imaging.

Non imaging applications:

Radiology information systems (RIS) patient Radiology information systems (RIS) patient admissions, scheduling, accounting, billing, admissions, scheduling, accounting, billing, film library functions, word processing, film library functions, word processing, statistics, database management and data statistics, database management and data communications. RIS can connect to hospital communications. RIS can connect to hospital information system (HIS) which address the information system (HIS) which address the needs of all departments in the hospital needs of all departments in the hospital including laboratory, pharmacy, finance, including laboratory, pharmacy, finance, admissions and hospital administration.admissions and hospital administration.

PACS:

Control databasesystem

Local area network(LAN)

Computermonitor

Film printer

Optical jukeboxor tape

RIS/HIS

Remoteinterface

Wide area network (WAN)

CT MRI CR

Communication

Archiving

Acquisition

Display

ANY Qs?