Understanding Low Energy Bluetooth Technology

Introduction

Bluetooth technology has transformed wireless communication between devices due to its universality and simplicity. Devices can communicate wirelessly with a high level of security via Bluetooth. Due to its low power consumption and cost, Bluetooth plays a crucial role in applications ranging from high-speed automotive devices to complex medical equipment.

The convenience and global recognition of Bluetooth allow any Bluetooth-enabled device to connect with nearby devices through a pairing process. Once paired, devices can establish full-duplex communication and transmit data and voice through a short-range dedicated network known as a “piconet.” A piconet can connect up to eight devices, with one device acting as the master and the others as slave devices within the network/piconet. The master device serves as a hub, and slave devices communicate with each other through the master device. Another significant feature of Bluetooth technology is its use of frequency hopping to minimize interference.

The full-duplex communication capability of Bluetooth technology provides users with numerous innovative features, such as connecting a mobile phone to Bluetooth speakers, hands-free calls while driving, sharing files between two laptops, and connecting game consoles to Bluetooth-enabled game controllers.

Low Energy Bluetooth:

Low Energy Bluetooth is an intelligent, low-power Bluetooth wireless technology. This technology enhances the intelligence of devices by reducing their size, price, and complexity.

Low Energy Bluetooth, also known as Smart Bluetooth, was initially part of the Bluetooth 4.0 core specification. Before being adopted by the Bluetooth Special Interest Group, it was designed by Nokia as a short-range wireless communication technology aimed at providing the lowest power wireless standard, specifically optimized for low cost, low bandwidth, low power, and low complexity. These design goals are reflected in the core specifications: Low Energy Bluetooth strives to become a low-power standard specifically designed for semiconductor manufacturers and low-power, low-cost practical applications. Currently, Low Energy Bluetooth technology is widely used and can operate for a long time on a single button battery.

While Low Energy Bluetooth is an excellent technology in itself, the reason for its widespread adoption is that it made the right compromises at the right time. Although it is a relatively new standard, the number of product designs incorporating Low Energy Bluetooth technology has far surpassed that of other wireless technologies at the same stage.

The challenges faced by traditional Bluetooth include rapid battery depletion and frequent disconnections, requiring frequent re-pairing. Low Energy Bluetooth has successfully addressed these issues, which is one of the reasons for its rapid development. The rapid advancement of smartphones, tablets, and mobile computing devices has further propelled the adoption of this technology. Major players in the mobile industry proactively adopted Low Energy Bluetooth, paving the way for its widespread use, which in turn encouraged semiconductor manufacturers to invest their limited resources into what they believe to be the most promising technology for long-term growth.

As the market for mobile devices and tablets matures, the connection demands between these devices and the external environment create significant growth potential. This presents an excellent opportunity for peripheral device suppliers to develop innovative devices that solve problems consumers may not even be aware of yet. Therefore, Low Energy Bluetooth has accumulated numerous advantages, providing flexible small product designers with the opportunity to enter the mass market with specific functions, creativity, and innovation, all while maintaining a relatively low design budget. Low Energy Bluetooth also enables these developers to communicate with any advanced mobile platform using easily accessible chips, tools, and standard designs.

Features

1. Lowest Power Consumption

From design to usage, everything is aimed at achieving the lowest power consumption. To minimize power usage, Low Energy Bluetooth devices spend most of their time in sleep mode. When activity occurs, the device is automatically awakened and sends a short message to a gateway, personal computer, or smartphone. The maximum/peak power consumption does not exceed 15 mA, with an average power consumption of about 1 µA. The power consumption during use is reduced to one-tenth that of traditional Bluetooth. In low-usage applications, a single button battery can sustain stable operation for 5 to 10 years.

2. High Cost-Effectiveness and Compatibility

To ensure compatibility with traditional Bluetooth technology and achieve cost-effectiveness for small battery-powered devices, two types of chipsets are available:

Dual-mode technology that supports both Low Energy Bluetooth and traditional Bluetooth functionalities.

Pure Low Energy Bluetooth technology optimized for low-cost and low-power small battery-powered devices.

3. Stability, Security, and Reliability

Low Energy Bluetooth technology utilizes the same Adaptive Frequency Hopping (AFH) technology as traditional Bluetooth, ensuring that Low Energy Bluetooth can maintain stable transmission in “noisy” radio frequency environments in residential, industrial, and medical applications. To minimize the cost and power consumption of using AFH, Low Energy Bluetooth technology has reduced the number of channels from the 79 1 MHz wide channels of traditional Bluetooth to 40 2 MHz wide channels.

4. Wireless Coexistence

Bluetooth technology, wireless LAN, IEEE 802.15.4/wireless personal area networks, and many proprietary radios all operate in the unlicensed 2.4 GHz Industrial, Scientific, and Medical (ISM) frequency band. Due to the numerous technologies sharing this radio frequency space, wireless performance can degrade due to interference leading to error correction and retransmissions (e.g., increased latency and reduced throughput). In demanding applications, interference can be reduced through frequency planning and special antenna designs. Since both traditional Bluetooth and Low Energy Bluetooth use AFH, which minimizes interference from other wireless technologies, Bluetooth transmission exhibits excellent stability and reliability.

5. Connection Range

The modulation of Low Energy Bluetooth technology is slightly different from that of traditional Bluetooth technology. This different modulation achieves a connection range of up to 300 meters using a 10 mW dBm wireless chipset (the maximum power of Low Energy Bluetooth).

6. Usability and Integration

Low Energy Bluetooth piconets are generally based on one master device connected to multiple slave devices. In a piconet, all devices are either master or slave, but cannot be both simultaneously. The master device controls the communication frequency of the slave devices, which can only communicate based on the master device’s requests. Compared to traditional Bluetooth technology, a new feature added in Low Energy Bluetooth technology is the “broadcast” feature. Through this feature, slave devices can notify that they need to send data to the master device. Broadcast messages also include activities or measurements.

Technical Details

Data Transmission – Low Energy Bluetooth supports the transmission of very small packets (8 to 27 octets) at a speed of 1 Mbps. All connections use an advanced low-power listening mode to achieve ultra-low duty cycles and minimize power consumption.

Frequency Hopping – Low Energy Bluetooth uses the common Adaptive Frequency Hopping technology of Bluetooth to minimize interference from other technologies within the 2.4 GHz ISM band. Efficient multipath advantages increase link budgets and effective operational ranges while optimizing power consumption.

Host Control – Low Energy Bluetooth features highly intelligent control capabilities. The host can remain in sleep mode for extended periods and is only awakened by the controller when needed. Since the power consumption of the host processor is generally higher than that of the Low Energy Bluetooth controller, this achieves maximum energy savings.

Latency – Low Energy Bluetooth supports connection setup and data transmission within 3 milliseconds. Thus, in short burst communications, applications can establish connections and transmit validated data within milliseconds before quickly disconnecting.

Distance – The increase in modulation index allows Low Energy Bluetooth to achieve a maximum distance of over 100 meters.

Stability – Low Energy Bluetooth uses robust 24-bit CRC on all packets to ensure optimal interference resistance.

Strong Network Security – Utilizing CCM’s complete AES-128 encryption technology provides strong packet encryption and verification, ensuring communication security.

Topology – BLE uses a 32-bit access address on each packet from slave devices, allowing for the connection of billions of devices. This technology is optimized for one-to-one connections while using a star topology for one-to-many connections.

Comparison Between Traditional Bluetooth and Low Energy Bluetooth

Applications

Because almost all portable devices support BLE, it can be applied to various new applications across different industries. For example, at exhibitions, BLE can help companies win new customers more effectively in the following ways:

Gaming – By rewarding exhibition attendees for finding Beacons placed in certain locations using Low Energy Bluetooth technology, exhibitors can attract these attendees to areas that are usually neglected.

Sponsorship – By pushing notifications to attendees via Beacons, encouraging them to check nearby booths when passing through specific areas of the exhibition, this can provide a premium service to sponsors, thus generating additional revenue.

Heat Maps – Beacons can gather real-time statistics, identify hotspots, and notify event managers of overcrowded areas that may pose safety risks.

Content Distribution – Attendees no longer have to wait for email delivery of conference slides. BLE Beacons can automatically send slides, e-books, and other materials to attendees during or after the conference.

Automatic Check-in – Event organizers can set up simulated check-in Beacons at the entrance of the venue to easily obtain information about attendance and view personal profiles in real time. Users do not need to be present. If users download the app and activate Bluetooth on their mobile devices, the app will automatically check them in when they walk into the venue.

Low Energy Bluetooth has developed a mature ecosystem. Developers can now access various chips and modules that accelerate the hardware and software development speed of BLE devices.