Short Range Wireless Technologies and Location Tracking

2.1 Short Range Technologies

• Definition: Includes wireless local area network (WLAN) and piconet.

• Coverage: Typically restricted to buildings, campuses, or single rooms.

• Operation: Operated by individuals without the need for a special network.

Practical Examples-

• Data transfer between mobile phones.

• Hands-free earphone-mic.

• Laptop connectivity to mobile.

• Office or company attendance punching through RFID cards.

Communication Methods

• Infrared Light Transmission: E.g., 900 nm wavelength.

• Radio Transmission: E.g., 2.4 GHz in the license-free ISM band.

Bluetooth

• Purpose: Aims at ad-hoc piconets.

• Coverage: Local area networks with limited coverage.

• Infrastructure: No need for infrastructure.

Zigbee

• Purpose: Developed as an open global standard.

• Use Case: Low-cost, low-power IoT networks.

Z-Wave

• Purpose: Wireless communication protocol.

• Use Case: Primarily used for home automation.

RFID

• Purpose: Method of data collection.

• Operation: Automatically identifies objects through low-power radio waves.

• Components: RFID tags, antenna, RFID reader, and transceiver.

2.1.1 Bluetooth

• Local Area Network: Acts as a local area network with very limited coverage and without the need for infrastructure.

• Proximity: Connects small devices in close proximity (about 10 meters) without expensive wiring or wireless infrastructure.

• Cord Replacement: Replaces cumbersome cords (e.g., printer cables, headphone cables, mouse cables) with an invisible, low-power short-range wireless connection, providing convenience and flexibility.

• Modem Standard: Promises to replace troublesome appliance communication cords with invisible wireless connections within a person's personal workspace.

• History: Named after King Harald Gormsen of Denmark. In 1994, Swedish IT company Ericsson initiated studies related to communicator link and Bluetooth technology. In 1998, Ericsson, Intel, IBM, Nokia, and Toshiba founded the Bluetooth consortium to develop a single-chip, low-cost, radio-based wireless network technology.

• Criteria Fulfillment: Bluetooth fulfilled criteria like market potential, compatibility, distinct identity, technical feasibility, and economic feasibility (IEEE 802.11).

2.1.1.1 Bluetooth Architecture

• Wireless Communication Network: Connects mobile devices wirelessly over a short range.

• Independent Model: Bluetooth architecture is an independent model with a stack of protocols, separate from the usual OSI model or TCP/IP model.

• Protocol Layers: Protocols in the Bluetooth standard are grouped into the physical layer, data link layer, middleware layer, and application layer.

1. Physical Layer

• Components: Includes Bluetooth radio and Baseband.

• Function: Lays down the physical structure and specifications for transmission of radio waves.

• Specifications: Defines air interface, frequency bands, frequency hopping specifications, and modulation techniques.

• Services: Takes the services of radio protocol.

• Addressing Scheme: Defines the addressing scheme, packet frame format, timing, and power control algorithms.

2. Data Link Layer

· Components: Includes Baseband, Link Manager Protocol (LMP), and Logical Link Control and Adaptation Protocol (L2CAP).

· Link Manager Protocol (LMP): Establishes logical links between Bluetooth devices and maintains the links for enabling communications. Other functions include device authentication, message encryption, and negotiation of packet sizes.

· Logical Link Control and Adaptation Protocol (L2CAP): Provides adaptation between upper layer frame and baseband layer frame format. Supports both connection-oriented and connectionless services.

3. Middleware Layer

· Components: Includes Radio Frequency Communications (RFComm) protocol, adopted protocols, Service Discovery Protocol (SDP), and AT commands.

· RFComm: Short for Radio Frontend Component. Provides a serial interface with WAP.

· Adopted Protocols: Protocols adopted from standard models, including Point-to-Point Protocol (PPP), Internet Protocol (IP), User Datagram Protocol (UDP), Transmission Control Protocol (TCP), and Wireless Application Protocol (WAP).

· Service Discovery Protocol (SDP): Manages service-related queries like device information to establish connections between contending Bluetooth devices.

· AT Commands: The ATtention command set.

4. Applications Layer

· Components: Includes application profiles that allow users to interact with Bluetooth applications.