What Is Data Transmission? How to Ensure Smooth Data Flow

Long-distance foot races, like marathons, are intriguing, aren't they?

Even more interesting is the story of Pheidippides. When Athens defeated the Persian force during the battle of Marathon, he ran 25 miles to deliver the victory message.

In ancient Athens, messengers ran long distances to convey important messages. As Phidippides approached the Acropolis, he praised Nike, the Greek goddess of victory, and collapsed dead because of exhaustion (keep in mind this is a myth, so events may be slightly exaggerated).

In data communication and networking, data transmission systems are equivalent to messengers like Pheidippides (without the whole death thing). To transfer analog and digital data among global business networks, companies use data exchange software or electronic data interchange (EDI) software. 

Organizations choose data transmission systems to ensure smooth data flow via information networks.

Importance of data transmission

Businesses multiply their strengths with mergers, acquisitions, and diversification. Effective decision making about such complex and different business environments requires contextual and connected data. 

Companies can’t have what they need from each other without fast data acquisition and transmission. Data communication solutions improve data transmission rates while protecting data quality within organizations with large data volumes. 

Furthermore, data transmission reduces hardware costs and gives people easy access to data when they need it.

Data transmission components

Data communication between two or more devices using a network relies on the following data transmission elements.

• Message is the data that a device sends to other devices. Common examples of messages are texts, audio files, and video files.
• Sender is the device that initiates the data transmission process of sending a message to another device.
• Receiver is the final device that gets the message.
• Transmission medium or channel bridges senders and receivers. Businesses can use guided, wired media or unguided methods such as radio waves, microwaves, or twisted pair cables to transfer data.
• Set of rules or protocols govern data communication between devices.

How does data transmission work?

Imagine keying in data to a computer using a keyboard. The electronics inside the keyboard use standard coding schemes to convert data inputs into equivalent binary coded patterns.

7 bits present 128 elements, while 8 bits present 256 elements in a keyboard. The receiver follows a similar process to decode received binary patterns and convert them into characters. 

Both senders and receivers use Extended Binary Coded Decimal (EBCDIC) and the American Standard Code for Information Interchange (ASCII) codes for representing alphabetic, punctuation, and numerical characters. 

Digital data transmission happens in a similar way. A source device generates data in the form of digital signals or bit streams. A communication medium like a physical copper wire, wireless network, or optical fiber transports this data to one or more recipient devices.

Each outward signal can be a baseband or passband. 

• Baseband or original message signal is the original information that’s intended to be transmitted. However, a baseband signal has a low frequency and can’t travel long distances without modulation.
• Passband signal refers to the original message after modulation. Therefore, passband signals are modulated differently than baseband signals.

Data transmission can also facilitate internal data transfer, like sending data from a hard disk or random access memory (RAM) to a processor. In most cases, data transmission is digital but can also be analog.

Types of data transmission

Data transmission modes vary depending on data exchange direction, numbers of bits transmitted, and synchronization between transmitter and receiver.

Data transmission modes can be classified into three categories based on their direction of information exchange. 

1. Simplex transmission

In simplex data transmission mode, data flows in one direction. This unidirectional communication restricts senders to sending and receivers to receiving only. Simplex isn’t a popular transmission model since most businesses need two-way communication. 

Devices using simplex transmission send more data using the entire channel bandwidth. However, there’s no inter-communication between devices because of the unidirectionality. 

Common examples of devices using simplex transmission models include keyboard and mouse. Radio stations also use simplex transmission to send signals to listeners who can’t transmit back. 

2. Half duplex transmission

Half duplex or semi-duplex transmission mode allows data to flow in both directions, but only one direction at a time. Basically, devices can transmit and receive data, but not simultaneously. Like simplex transmission, the half-duplex transmission uses the entire channel bandwidth in one direction at a time.

Imagine talking via a walkie-talkie, a classic example of half duplex transmission. You can only listen when another person speaks. Similarly, they can only listen when you speak. If you both try to speak at the same time, you’ll hear nothing but a distorted sound.

Half duplex transmission causes communication delay as you have to wait while the other party sends data. 

3. Full duplex transmission

Communication in full-duplex transmission mode is bi-directional. Data flows in both directions, allowing both devices to send and receive messages simultaneously. The full duplex transmission uses two simplex channels that move traffic in opposite directions. A full duplex is the fastest communication mode between devices.

A telephone network uses full duplex transmission to let two people talk and listen at the same time. However, the full duplex mode needs a dedicated path to ensure seamless communication between two devices. 

You can divide data transmission modes into two categories depending on the synchronization between receivers and transmitters.

Synchronous transmission

Synchronous transmission is a full duplex-type transmission that uses clock signals to keep the transmitter and receiver in step with one another. This data transfer method packages and sends data in large blocks at fixed time intervals. Clock signals in transmitter and receiver ensure continuous and consistent time-based data block transfer.

Now, let’s break down how synchronous transmission works.

• Data block grouping inserts synchronous idle characters (also known as syn characters) to space data blocks at regular intervals.
• Connection synchronization occurs after remote devices receive and decode syn characters.
• Data transmission begins after the correct connection synchronization.

Synchronous data transmission sends data blocks instead of characters, so it's fast – precisely why businesses transferring large amounts of data love this model. However, this data transmission can be expensive. 

Central processing units (CPU), RAM, and network protocols like Ethernet use synchronous transmission.

Asynchronous transmission

Asynchronous transmission is a half duplex-type transmission that uses start (binary 0) and stop (binary 1) bits to mark the beginning and end of characters during data transfer. It doesn't matter what you send; each character must start with 0 and end with 1 for a device to know it has received or sent a complete character.

Onto understanding how asynchronous transmission works.

• Mark state refers to gaps between character transmissions in an inactive transmission line. Asynchronous transmission uses binary 1 to denote periods of inactivity.
• Mark state interruption happens when a receiving system sees a binary 0. At this stage, the system anticipates the arrival of data characters.
• Asynchronous data transmission occurs as the systems receive characters and returns to the mark state when the transmission ends. 

Since there's no clock mechanism, asynchronous communication devices don’t send or receive information at a steady pace. In spite of this, they maintain reliable information flow by negotiating speed as per hardware capabilities. 

Asynchronous data transfer is best for low-speed transmissions. You can always compress data to boost speed. When you key in data using a keyboard, that’s a classic example of asynchronous data transfer.

Synchronous vs. asynchronous transmission

Synchronous transmission uses timing signals to send a continuous stream of data, whereas asynchronous transmission transfers data at a random time interval.  

There are two categories of data transmission based on the number of simultaneous bits transferred over a network.

Serial transmission

Serial data transmission receives or sends data using a single packet of data bits at every clock pulse. It uses bi-directional communication to transfer data via a computer bus or communication channel. Serial transmissions generally convey 8 bits at a time along with a start and stop bit. 

Data transfer among two computers using serial ports is an example of serial transmission.

Serial transmission is suitable for long-distance data transmission because of its simplicity and low cost. The data transfer speed, however, is comparatively slow due to a single communication channel. 

Parallel transmission

Parallel data transmission transfers multiple data bits simultaneously. In this mode of transmission, parallel wires do the heavy lifting by containing data. Other cables help transmitters and receivers communicate with each other. 

The way a computer communicates with a printer is a good parallel data transmission example. 

Parallel transmission is ideal for sending a large volume of data in a shorter time. That’s why you often see it in short-distance communication. However, two transmission channels too close to each other can interfere with data signal quality. This transmission mode is also expensive as it needs more channels.

Serial vs. parallel transmission

Serial transmission uses a single communication channel to transfer data, whereas parallel transmission deploys multiple parallel links to transmit data simultaneously.

Types of data transmission media

Data transmission media can be divided into guided and unguided media. 

Wired, bounded, or guided transmission media ensures high speed and secure data transmission using physical links. Guided media, ideal for shorter distances, has five major types.

1. Twisted pair cable is the most widely used transmission media. It’s basically a winding of two separately insulated conductor wires. A twisted pair cable contains several such pairs in a protective cover. Shielded twisted pair (STP) cables block external interference with a special jacket. Unshielded twisted pair (UTP) cables can block interference without physical shields.
2. Coaxial cable uses both baseband and broadband modes to transmit information. These cables come with insulation layers and parallel conductors with protection covers. Analog television networks and cable televisions use coaxial cables.
3. Optical fiber cable transmits large volumes of data using light reflection through a glass or plastic core. These cables can be bi-directional or unidirectional.
4. Stripline is a transverse electromagnetic (TEM) transmission line that sends high-frequency waves using a conducting material.
5. Microstripline uses a dielectric layer to separate the conducting material from the ground plane.

Unbounded, wireless, or unguided transmission media broadcast messages using electromagnetic signals. It transmits the following types of signals.

• Radio waves can send signals through buildings. These waves don’t require alignment between sending and receiving antennae. Common examples include cordless phones and frequency modulation (FM) radios.
• Microwaves use proper alignment between sending and receiving antennae (also known as line of sight transmission) to send signals. Microwaves are commonly used in mobile phone communication.
• Infrared waves facilitate short-distance communication; they can’t penetrate through physical obstacles.

Data transmission channel capacity

Bandwidth and data transfer rate are two parameters that businesses use to measure data transmission channel capacity.

Bandwidth refers to the frequency ranges available for data transmission through a channel. The higher the bandwidth, the faster the data transfer rate. Channel bandwidth is measured in Hertz (Hz).

Data transfer rate, or bit rate, measures the number of bits transmitted per second between source and destination. Data transfer rate is measured in bits per second (BPS). For example, 1 kilobit per second (KBPS) equals 1024 BPS. 

Let’s look at what to consider when choosing a data transmission mode.

Data transmission protocols and standards

Every domain plays by its own rules, and data transmission systems are no different. These rules or protocols dictate how the sending and receiving ends of a system work.

Data transmission protocols define three elements:

1. Syntax is the data structure or format that devices use while sending or receiving data. For example, a protocol may consider the first eight data bits as the sender’s address and the rest of the data stream as a message.
2. Semantics define how receivers and senders interpret each section of a data bit. For example, what action does a receiver take after receiving data? How does it interpret the data it received?
3. Timing tells you what data to send and at what speed. Setting timing is crucial because you don’t want the receiver to lose data just because a sender device can transmit data lightning fast.

When learning about data communication, you’ll come across De Facto and De Jure standards.

De Facto standards are rules that companies adopt because of their widespread use. These standards aren’t approved by any organization. For instance, you can establish a standard at your company depending on its needs. 

De Jure standards are regulations set by recognized bodies like the American National Standards Institute (ANSI), the International Organization for Standardization (ISO), and the Institute of Electrical and Electronics Engineers (IEEE).

For example, data communication protocols follow simple mail transfer protocol (SMTP) or transmission control protocol (TCP) in certain cases. 

Keep reading to explore common data communication etiquette.

• Data sequencing breaks down a bigger message into smaller data packets. These smaller chunks make it easy for devices to spot errors. Plus, they have to resend smaller data quantities in case of errors.
• Data routing helps sources and destinations find the most efficient path between them. Finding the right data route is critical to boosting data transmission efficiency.
• Data flow ensures proper data delivery regardless of the speed mismatch between a receiver and sender.
• Error control does what it says – it spots errors and helps devices recover. It also ensures there’s no interruption in data sending or receiving.
• Coding process is what computers use to convert data into binary forms.

Data security is vital to any business. However, how do you ensure data doesn't leak while traveling? You use secure data transmission methods.

Data transmission and CDN

Data transmission is more than sending and receiving data. It decides whether a business succeeds in processing complex tasks or not.

For example, the data you receive may fuel business applications and help you make decisions. So you don’t want a sub-par data transmission under any circumstances – precisely why companies sincerely address issues like server health, data transmission structure, latency, and network congestion. 

Businesses often rely on content delivery network (CDN) solutions to ensure seamless data distribution. CDNs help you use the network efficiently by utilizing nodes strategically located around the globe. As a result, you can easily avoid network congestion and offer a better user experience. 

Most CDNs come with built-in load balancers to help senders and receivers access the closest entry and exit points. This ease of data transmission improves speed. Also, CDNs help protect your data from emerging threats. 

Run your own marathon

Operating a business is a marathon, not a sprint. You need efficient data transmission systems, like Pheidippides, to share information across networks and make decisions. Start by deciding which transmission mode works best for you so that you leverage it to create your legacy.

If you’re looking to share data among companies and stakeholders without changing the inherent meaning, it’s time to start using data exchange.