4 Data connections

hardware

A interface is an architecture used to interconnect two (2) devices together

De facto standard

• – it is something that is used so widely that it is considered a standard for a given application although it has no official status.

Composition

• – it is the whole content of an entity of an interface standard.

o Electrical component

deals with voltages, line capacitance, and other electrical issues.

Mechanical component

o deals with items such as the connector or plugs description

Functional component

o deals with the function of each pin used in an interface.

Procedural component

o describes how the circuits are used to perform an operation.

Examples of Interfaces:

1. USB

2. Fire wire

3. Thunderbolt

4. Lightning

5. SCSI

6. Infiband

7. Fibre Channel

Universal Serial Bus (USB)

• - It is a digital interface that uses a standardized connector (plug) for all serial and parallel type devices which provides a digital interface and known for being hot-pluggable

Fire Wire

• – It is a type of interconnection between peripheral devices (such as wireless modems and high-speed digital video cameras) and a microcomputer

Thunderbolt

• – It is currently found on Apple laptops and provides a 10-Gbps connection to peripheral devices.

Lightning

• - It is an 8-pin connector in which it can be found as the primary connector on the newer versions of Apple's iPhone as well as Apple devices such as the iPad.

• SCSI - SCSI,

which stands for Small Computer System Interface is a technique for interfacing a computer to high-speed devices such as hard disk drives, tape drives, CDs, and DVDs.

InfiniBand

• – This interface is used due to its high-speed connection that is mostly found in networks that require large amounts of peripheral storage.

Fibre Channel

• is like InfiniBand in that it too is a serial, high-speed network that connects a computer to multiple input/output devices

Asynchronous connection

- a single character, or byte of data, is the unit of transfer between the sender and receiver. The sender prepares a data character for transmission, transmits that character with irregular timing, and then begins preparing the next data character for transmission

Synchronous connection

- the unit of transmission is a sequence of characters. This sequence of characters may be thousands of characters in size with regular timing sent

Isochronous connection

- a special kind of data link connection used to support various types of real-time applications such as streaming voice, video, and music

Data Transmission Factors:

1. bandwidth

2. radiation

3. noise absorption

4. Attenuation

Bandwidth of Data Transmission Factors

- refers to the data-carrying capacity of a channel or medium. Higher bandwidth communication channels support higher data rates

Radiation

- refers to the leakage of signal from the medium due to undesirable electrical characteristics of the medium.

Noise Absorption

- refers to the susceptibility of the media to external electrical noise that can cause distortion of the data signal

Attenuation

- refers to the loss of energy as signal propagates outwards. The amount of energy lost depends on frequency. Radiations and physical characteristics of media contribute to attenuation.

Bandwidth

• Bandwidth is the measurement of the ability of an electronic communications device or system to send and receive information

Hertz

o - Bandwidth in hertz is the range of frequencies contained in a composite signal or the range of frequencies a channel can pass

Bits per Seconds

o - The term bandwidth can also refer to the number of bits per second that a channel, a link, or even a network can transmit

Throughput

• is the amount of data that enters and goes through a system. In layman’s term, it is a measure of how fast we can actually send data through a network.

Latency

It is a measure of delay. It measures the time it takes for data to get to its destination across the network.

Propagation time

o measures the time required for a bit to travel from the source to the destination.

Transmission time

o measures the time how long a message will pass in channel corresponding with the bandwidth.

Queuing time

o measures the time needed for each intermediate or end device to hold the message before it can be processed

Processing delay

o measures how data is processed through or from links.

Bit Rate

• is the amount of data (number of bits) that can be transmitted per second. Bit rate is closer to bandwidth, but it is often per host or source to destination devices.

• Baud Rate

refers to the number of signal elements or symbol changes that occur per second. A symbol is one of several voltage, frequency, or phase changes

switched network,

• data is transferred from source to destination through a series of intermediate switching nodes. Data passes through a subset of the network nodes

Circuit switching

o involves establishing a path from source to destination before the commencement of communication. The path is dedicated to the source-destination pair for the duration of the communication session

Packet switching

o involves organizing data in blocks called packets that are sent in a store-and-forward manner without prior establishment of the communication path. By store-and-forward, we mean that when a node receives a packet, it stores the packet and checks it for errors

broadcast network,

a transmission from a source is received by all nodes in the network. A broadcast network ensures that all the nodes in the network see the transmitted data