RFBluetooth vs BLE: Key Differences Explained
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This article explores the differences between Bluetooth and Bluetooth Low Energy (BLE) technologies, both of which are Wireless Personal Area Network (WPAN) standards. BLE was specifically developed for sending small data packets, making it ideal for Internet of Things (IoT) devices powered by coin cell batteries.
Bluetooth, on the other hand, is commonly used for applications requiring more substantial data exchange, such as wireless headsets and other consumer electronics. BLE finds its niche in areas like mobile payments, healthcare, ticketing, and access control. Both technologies offer cost-effective solutions.
Both Bluetooth and BLE networks operate with a master-slave architecture.
Bluetooth
Bluetooth is a ubiquitous wireless technology found in almost all mobile devices. It facilitates the transfer of files (text, photos, videos, etc.) between mobile phones and other compatible devices.
Operating in the 2.4 GHz band, Bluetooth creates a Personal Area Network (PAN) for communication. As a connection-oriented technology, a connection must first be established between Bluetooth-enabled devices before data transfer can occur. The Bluetooth Special Interest Group (SIG) manages the standard.
Different Bluetooth versions exist, each offering varying speeds and coverage ranges. (Refer to the Bluetooth tutorial for more details).
BLE - Bluetooth Low Energy
Bluetooth version 4.0 introduced Bluetooth Low Energy (BLE), also known as Bluetooth Smart or Wibree. This is a low-power variant of the traditional Bluetooth standard.
Like Bluetooth, BLE is also managed by the Bluetooth SIG. Due to its low power consumption and sleep modes, BLE devices can operate for years on a coin cell battery. It operates in the same 2.4 GHz band as standard Bluetooth but utilizes a different Frequency Hopping Spread Spectrum (FHSS) scheme.
BLE devices are incompatible with standard Bluetooth devices, meaning they cannot directly communicate with each other. To achieve interoperability, dual-mode devices equipped with both protocol stacks are necessary. Many vendors, including CSR, Broadcom, Nordic Semiconductor, EM Microelectronics, and Texas Instruments, have developed dual-mode BLE hardware chips. (Refer to BLE basics for more information).
Bluetooth vs BLE: A Tabular Comparison
The following table highlights the key differences between Bluetooth and BLE technologies:
| Specifications | Bluetooth | BLE (Bluetooth Low Energy) |
|---|---|---|
| Network/Topology | Scatternet | Star, Bus |
| Power consumption | Low (less than 30 mA) | Very Low (less than 15 mA) |
| Speed | 700 Kbps | 1 Mbps |
| Range | <30 m | 50 meters (150 meters open field) |
| RF Frequency band | 2400 MHz | 2400 MHz |
| Frequency Channels | 79 channels (2.400 GHz - 2.4835 GHz, 1 MHz spacing) | 40 channels (2402MHz - 2480 MHz, 3 advertising, 37 data channels) |
| Modulation | GFSK (0.35 index), π/4 DQPSK, 8DPSK | GFSK (0.5 index) |
| Data transfer latency | Approx. 100 ms | Approx. 3 ms |
| Spreading | FHSS (1MHz channel) | FHSS (2MHz channel) |
| Link layer | TDMA | TDMA |
| Message size (bytes) | 358 (Max) | 8 to 47 |
| Error detection/correction | 8 bit CRC (header), 16 bit CRC, 2/3 FEC (payload), ACKs | 24 bit CRC, ACKs |
| Security | 64b/128b, user defined application layer | 128 bits AES, user defined application layer |
| Application throughput | 0.7 to 2.1 Mbps | less than 0.3 Mbps |
| Nodes/Active Slaves | 7 | Unlimited |
