Radio Protocol Architecture

Radio protocol architecture refers to the set of rules and conventions governing the communication between different entities in a radio communication system. These protocols ensure that devices can effectively communicate with each other over the airwaves.

1. Physical Layer:
   • Modulation/Demodulation: This layer deals with the conversion of digital data into analog signals for transmission (modulation) and the reverse process (demodulation) at the receiver end. Modulation techniques include amplitude modulation (AM), frequency modulation (FM), and phase modulation (PM).
   • Channel Coding/Decoding: The physical layer also involves adding error-detection and error-correction codes to the transmitted data to ensure reliable communication. Channel coding helps mitigate the effects of noise and interference.
   • Multiplexing/Demultiplexing: Multiple signals may share the same channel in radio communication. Multiplexing allows combining these signals for transmission, while demultiplexing separates them at the receiving end.
2. Data Link Layer:
   • Medium Access Control (MAC): This layer is responsible for managing access to the shared communication medium, especially in scenarios where multiple devices compete for access. It involves protocols like Carrier Sense Multiple Access (CSMA) for channel access.
   • Logical Link Control (LLC): LLC provides flow control, error checking, and framing of data for reliable communication between devices. It ensures that data is correctly and efficiently transferred between devices.
3. Network Layer:
   • Routing: The network layer handles the routing of data between different devices in a network. It determines the best path for data to travel from the source to the destination, taking into account factors such as network topology and traffic conditions.
   • Addressing: Each device in a network is assigned a unique address, and the network layer is responsible for addressing and routing data packets based on these addresses.
4. Transport Layer:
   • Segmentation/Reassembly: This layer divides large messages into smaller segments for transmission and reassembles them at the destination. It also ensures the reliability and integrity of data transfer through mechanisms like acknowledgment and retransmission.
5. Session Layer:
   • Session Establishment, Maintenance, and Termination: This layer manages the establishment, maintenance, and termination of communication sessions between devices. It ensures that data is synchronized and organized into manageable sessions.
6. Presentation Layer:
   • Data Formatting and Translation: The presentation layer is responsible for formatting and translating data between the application layer and the lower layers. It ensures that data is presented in a format that the application layer can understand.
7. Application Layer:
   • End-User Services: The application layer provides end-user services and network-based application services, such as file transfer, email, and remote login. It directly interacts with the end-user applications.

In practical implementations, these layers may be combined or adapted based on the specific requirements of the radio communication system. Additionally, standards like the OSI model or the TCP/IP model may not be strictly followed, as some protocols may have unique architectures tailored to their specific use cases.