Bluetooth vs. Bluetooth Low Energy: A Detailed Comparison

Bluetooth Technology Overview

When it comes to the definition of Bluetooth technology, you may know that it is a short-range wireless communication standard. Over the years, the Bluetooth SIG has released various versions of the Bluetooth specification. In fact, keeping all the different Bluetooth versions running properly is not an easy task. Here are the basics of Bluetooth and Bluetooth low energy:

What is Classic Bluetooth?

The original version, now known as Bluetooth Classic, is the cornerstone of the wireless connectivity we are familiar with. Generally speaking, Bluetooth Classic refers to the original Bluetooth technology available before Bluetooth 4.0 – Basic Rate (BR), Enhanced Data Rate (EDR), and Amplified (AMP). It operates over 79 channels in the 2.4GHz band, enabling devices such as phones and headsets to form a personal area network (PAN) to transmit data over short distances.

In fact, Classic Bluetooth is not an official term. It is a convenient reference to the original BR/EDR/AMP technology suite defined by the Bluetooth SIG, showing the dynamic evolution of the technology. Moreover, one of its most notable roles is as the key to pairing audio devices with mobile phones. Classic Bluetooth is becoming more and more important to everyday life, especially as the trend of smartphone devices without headphone jacks continues. The process of connecting two devices via Classic Bluetooth is now a common skill.

What is Bluetooth Low Energy?

As part of the Bluetooth 4.0 core specification, Bluetooth Low Energy (BLE) represents a huge leap forward in energy efficiency in the Bluetooth ecosystem. Also known as Bluetooth Smart, BLE shares the same management and supervision as the Bluetooth SIG. Its notable features are its lowest power consumption and energy-saving sleep modes. As a result, this enables BLE devices to operate for long periods of time using small coin-cell batteries.

BLE operates in the same 2.4GHz frequency range as standard Bluetooth, but uses a unique frequency-hopping spread spectrum (FHSS) scheme. While BLE shares the same radio spectrum as its predecessor, it operates at about half the data rate, achieving a balance between power conservation and effective communication range.

In essence, Bluetooth Low Energy is not just a simplified version of Classic Bluetooth, but a specialized and efficient iteration that caters to a range of applications that require energy-efficient wireless connectivity.

Bluetooth Classic vs. Bluetooth Low Energy: A Feature-by-Feature Comparison

The above introduces the basics of Bluetooth and Bluetooth LE. Let’s compare some key technical differences between classic Bluetooth and Bluetooth LE:

Battery consumption

While Classic Bluetooth is very energy efficient compared to other wireless standards, BLE takes power consumption even further. Classic Bluetooth has higher power requirements, while Bluetooth Low Energy can run for years on just a single coin cell battery. For IoT applications that require sustained low power consumption, BLE is the clear winner.

Data transfer rate

Classic Bluetooth has a maximum data rate of about 3Mbps, while Bluetooth Low Energy has a maximum data rate of about 1Mbps. However, BLE's lower rate is sufficient for periodic transmission of small amounts of data, a common IoT use case. The higher throughput of Classic Bluetooth comes at the expense of higher power consumption.

Delay

Latency refers to the time delay required for a data packet to be successfully transmitted. Bluetooth Low Energy actually achieves a lower latency time of about 6 milliseconds compared to 100 milliseconds for Classic Bluetooth. As a result, BLE enables more responsive device communications, which is critical for real-time IoT applications.

scope

Bluetooth 5.0 significantly increases the maximum range of Bluetooth to about 800 feet or 240 meters. In practice, however, the typical reliable range of classic Bluetooth remains around 30m and the typical reliable range of Bluetooth Low Energy remains around 50m. Outdoors, within line of sight, BLE has an optimal range of up to 150m. Despite the improvements in Bluetooth 5.0, the range is determined by antenna design and transmission power, not differences between the core technologies themselves.

Topology

Topology refers to how devices connect and communicate within a network. Classic Bluetooth uses a simple point-to-point topology where two devices communicate directly. Bluetooth Low Energy supports point-to-point as well as star topologies where many devices communicate with a central master device. Additionally, BLE offers broadcasting from one device to multiple devices as well as Bluetooth mesh networking. The additional topology options in Bluetooth LE make its network architecture more flexible and scalable for IoT implementations.

Advantages and Disadvantages of Classic Bluetooth and BLE

As Bluetooth has diversified into standards that meet different needs, it is important to understand the advantages and limitations of each. Now let’s summarize some of the main advantages and limitations of LE Bluetooth vs. Classic Bluetooth:

Advantages of Classic Bluetooth

• Higher throughput: Classic Bluetooth has a higher data transfer rate of approximately 3Mbps, allowing for fast transfer of large files such as audio streaming.
• Backward Compatibility: Classic Bluetooth maintains backward compatibility with legacy devices, preserving connectivity with older accessories.
• Proven technology: As a long-established standard, Classic Bluetooth benefits from decades of refinement and broad compatibility.

Disadvantages of Classic Bluetooth

• High power consumption: Due to the high power requirements during transmission and discovery, the battery life of Bluetooth devices is quickly depleted.
• Slow connection speed: Classic Bluetooth has a latency of about 100 milliseconds, which is lagging for applications that require fast back-and-forth communication.
• Limited topologies and connections: Classic Bluetooth only offers a simple point-to-point topology and limits slave connections to 7 devices.

Advantages of Bluetooth Low Energy

• Low power consumption: Only a small battery is needed to last for months or years, making it ideal for IoT devices.
• Optimized latency: Latency as low as 6 milliseconds enables responsive control applications.
• Low cost: The low cost of chipsets and components makes BLE devices very low cost.

Disadvantages of Bluetooth Low Energy

• Lower data rates: Maximum data rates are around 1-2Mbps, which is not suitable for high-bandwidth communications and is much lower than WiFi/cellular networks.
• Limited range: Typical coverage is less than 200m, even within line of sight.
• Environmental effects: Obstacles such as walls or bodies can degrade performance.

Bluetooth vs. Bluetooth Low Energy: Different Use Cases

Classic Bluetooth and Bluetooth Low Energy are suitable for different applications according to their functions. As discussed earlier, Classic Bluetooth is most commonly used in audio devices such as wireless headphones and speakers, as well as file transfers between devices. In fact, it is intended for direct use by ordinary consumers, who can easily purchase and use these Bluetooth devices.

In contrast, BLE is optimized for commercial IoT devices due to its efficiency in periodic data collection with low power consumption. While BLE is also used in personal devices such as fitness trackers that focus on data collection, it is heavily used in healthcare monitors and industrial environments for location services and condition monitoring. BLE's low power consumption and high efficiency make it an ideal choice for IoT use cases involving frequent small data transfers.

Considering the above comparison, here are the different use cases for Classic Bluetooth vs Bluetooth Low Energy:

Common Classic Bluetooth use cases include:

• Wireless headphones and speakers for streaming music
• Connect a wireless keyboard, mouse, and printer
• Hands-free calling in the car
• File transfer between devices
• Providing Internet connection via tethering

Bluetooth Low Energy is optimized for compact IoT devices that collect small amounts of sensor data. Common BLE use cases include:

• Connect to wearable fitness trackers to monitor steps, heart rate, and more
• Smart home sensors for temperature, motion, and more
• Location beacons provide proximity services
• Industrial IoT sensor networks for condition monitoring
• Healthcare devices that require low power consumption, such as blood glucose monitors
• Public transportation app that detects nearby buses/trains

Summarize

In short, Bluetooth technology will continue to play an important role in the future. Through continuous innovation and progress, it will provide more convenient and efficient wireless connection solutions for applications in various fields and promote the development of digitalization and intelligentization.