Network

Network#

Network Module Design#

Overview#

The network module provides a unified framework for managing and utilizing multiple network interfaces, specifically Ethernet and Wi-Fi. It is designed to support scenarios where either one or both interfaces are used concurrently, ensuring flexibility, efficiency, and reliability.

Requirements#

Functional Requirements#

  • Interface Support:

    • Support both Ethernet and Wi-Fi interfaces.

    • Allow operation with either one or both interfaces.

  • Transition and Parallel Usage:

    • Enable parallel usage of both interfaces.

    • Support interface transitions (e.g., fallback from Ethernet to Wi-Fi).

  • Data Communication:

    • Provide TCP/UDP-based data transmission and reception.

  • Automatic Recovery:

    • Reconnect automatically in case of disconnection.

Non-Functional Requirements#

  • Modular Design:

    • Keep interfaces independent for better maintainability.

  • Scalability:

    • Ensure ease of adding new interfaces like LTE in the future.

  • Power Efficiency:

    • Minimize power consumption for embedded systems.

  • Real-Time Operation:

    • Ensure timely data handling for latency-sensitive applications.

Design Principles#

  • Abstraction:

    • Abstract interface details to allow the upper layers to function independently of the specific hardware interface.

  • Modularity:

    • Separate interface management (Ethernet, Wi-Fi) from protocol logic.

  • Flexible Interface Selection:

    • Allow users to explicitly choose interfaces or let the system select the most appropriate one.

Architecture#

Layered Structure#

  • Application Layer:

    • Provides APIs for data transmission and reception, hiding interface-specific details.

  • Network Manager Layer:

    • Handles interface selection, status monitoring, and fallback logic.

  • Interface Layer:

    • Includes drivers for Ethernet and Wi-Fi, exposing a unified interface for the network manager.

  • Hardware Layer:

    • Communicates directly with the underlying hardware (e.g., MCU peripherals).

Data Flow#

  • Transmission: Application → Network Manager → Selected Interface → Hardware

  • Reception: Hardware → Selected Interface → Network Manager → Application

Key Components#

  • network_manager:

    • Controls the overall network operations, including interface prioritization and transitions.

    • Manages interface health checks and recovery.

  • interface_driver:

    • Manages specific interfaces such as Ethernet and Wi-Fi.

    • Provides a unified API for initialization, data transfer, and status checks.

    • Examples: ethernet_driver, wifi_driver.

  • network_protocol:

    • Implements protocol logic such as TCP and UDP.

    • Interfaces with drivers for data transmission and reception.

  • connection_monitor:

    • Periodically checks interface connectivity.

    • Initiates reconnection attempts if necessary.

State Transition Diagram#

Network Module State Diagram

State Transition Table#

  • S0: Off

  • S1: Initializing

  • S2: Initialized or Disabled

  • S3: Enabling

  • S4: Enabled

  • S5: Connecting

  • S6: Connected

Current

Event

Next

Note

S0

Turn on

S1

S1

Turn off

S0

S1

Initializing error

S0

S1

Initializing timeout

S0

S1

Initialized

S2

S2

Turn off

S0

S2

Enable

S3

S3

Turn off

S0

S3

Enabling error

S2

S3

Enabling timeout

S2

S3

Too many retries

S0

S3

Enabled

S4

S4

Turn off

S0

S4

Disabled

S2

S4

Connect

S5

S5

Turn off

S0

S5

Disabled

S2

S5

Connecting error

S4

S5

Connecting timeout

S4

S5

Disconnected

S4

S5

Too many retries

S0

S5

Connected

S6

S6

Turn off

S0

S6

Disabled

S2

S6

Disconnected

S4

APIs#

Initialization and Deinitialization#

  • netmgr_init(): Initializes the network manager.

  • netmgr_deinit(): Deinitializes the network manager.

  • netmgr_enable(): Enables the network manager.

  • netmgr_disable(): Disables the network manager.

Interface Management#

  • netmgr_register_iface(): Registers a new interface with the network manager.

Data Transmission and Reception#

Server interface provided for data transmission and reception.

Status Monitoring#

  • netmgr_state(): Retrieves the current state of the network manager.

  • netmgr_connected(): Checks if the network manager is connected.

Future Scalability#

  • Adding New Interfaces:

    • Introduce new drivers (e.g., LTE) with the same interface_driver structure and register them in the network manager.

  • Quality of Service (QoS):

    • Implement prioritization for critical data flows.

  • Load Balancing:

    • Optimize bandwidth by distributing traffic across multiple interfaces.

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