Bluetooth technology is standardized under the IEEE 802.15.1 standard, which is part of the IEEE 802 family of standards for local and metropolitan area networks. Here’s a detailed technical breakdown:
IEEE 802.15.1 Overview
The IEEE 802.15.1 standard specifies the Medium Access Control (MAC) and Physical Layer (PHY) for Wireless Personal Area Networks (WPANs) based on Bluetooth technology. It was initially based on the Bluetooth 1.1 specification and later updated to align with Bluetooth 1.2.
Key Components of IEEE 802.15.1
1. Physical Layer (PHY)
- Radio Frequency (RF) Specifications: Operates in the 2.4 GHz ISM band with 79 channels spaced 1 MHz apart.
- Modulation: Uses Gaussian Frequency Shift Keying (GFSK) for basic rate (1 Mbps) and Enhanced Data Rate (EDR) with Phase Shift Keying (PSK) for higher rates (2 Mbps and 3 Mbps).
2. Medium Access Control (MAC)
- Logical Link Control and Adaptation Protocol (L2CAP): Provides multiplexing of data from different higher-layer protocols, segmentation and reassembly of packets, and quality of service (QoS) management.
- Link Manager Protocol (LMP): Manages link setup, authentication, link configuration, and power control.
- Baseband: Handles physical channel access, timing, and error correction. It supports both synchronous (SCO) and asynchronous (ACL) data links.
3. Service Access Points (SAPs)
- Defines interfaces for higher-layer protocols to access MAC services. This includes Logical Link Control (LLC) interfaces for data link layer services.
Evolution and Updates
- IEEE 802.15.1-2002: The initial standard, aligning with Bluetooth 1.1.
- IEEE 802.15.1-2005: Updated to incorporate features from Bluetooth 1.2, including adaptive frequency hopping (AFH) to reduce interference from other wireless technologies.
Coexistence and Interference Management
- IEEE 802.15.2: Addresses coexistence issues with other wireless technologies operating in the same frequency band, such as Wi-Fi (IEEE 802.11).
Current Status
The IEEE no longer maintains the 802.15.1 standard, and the Bluetooth Special Interest Group (SIG) now oversees the development and maintenance of Bluetooth specifications.