Open Hardware and open firmware in OSI Layer 1

1. Describe OSI Layer 1.

2. Describe the hardware associated with OSI Layer 1.

3. Describe existing projects that either have developed or are developing open hardware that will work in OSI Layer 1. When I say open hardware, I mean hardware that uses Free Software/open-source philosophies in their designs.

4. What open protocols and Free Software/open source design principles are used in OSI Layer?

5. Has anyone implemented open firmware for OSI Layer 1 devices? If so, please fully explain them.

1. OSI Layer 1 Description

The OSI (Open Systems Interconnection) model is a conceptual framework used to understand network interactions in seven layers. Layer 1, known as the Physical Layer, is foundational, dealing with the hardware transmission of raw bits over a communication channel. It encompasses all the hardware, electrical, and physical specifications for devices. In essence, the Physical Layer is responsible for the actual physical connection between devices. It translates communication requests into hardware-specific operations, ensuring that when one device sends data, another device on the network can receive it accurately. This layer involves specifications such as:

• Electrical and physical specifications of devices
• Layout of pins, voltages, line impedance
• Physical data rates
• Maximum transmission distances
• Physical connectors and interfaces (e.g., optical fiber, Ethernet cables, and wireless transmission methods)

2. Hardware Associated with OSI Layer 1

Hardware devices and media that operate at the Physical Layer include:

• Network cables, such as coaxial cables, fiber optic cables, and twisted pair cables
• Connectors and interfaces like RJ45 for Ethernet cables, SC/ST connectors for fiber optics
• Hubs and repeaters, which regenerate signals to extend the transmission distance
• Network interface cards (NICs), which provide the physical interface for network connectivity in computing devices
• Switches and routers (although these devices operate at higher layers, they contain physical layer components to connect and transmit signals)

3. Open Hardware Projects for OSI Layer 1

Several projects and initiatives have embraced the open hardware philosophy, aiming to create accessible, modifiable, and free-to-use hardware designs for network devices. Some notable projects include:

• LibreRouter: This project aims to create open-source hardware for wireless community networks. The LibreRouter is designed as an outdoor wireless router, supporting high-performance mesh networking and being easily deployable in varied environments.

• Open Compute Project (OCP): Initially started by Facebook, this project focuses on sharing designs of data center products among companies, including servers and network devices. They work on openness in hardware designs that can be used in data centers, which indirectly impacts OSI Layer 1 through the design of network interfaces and physical infrastructure.

• OSHWA (Open Source Hardware Association): While not limited to networking hardware, OSHWA promotes and certifies open-source hardware of all kinds. Networking projects under this umbrella can include anything from simple connectors to more complex networking hardware.

4. Open Protocols and Free Software/Open Source Design Principles in OSI Layer 1

In the context of the Physical Layer, "open protocols" typically refer to the specifications and standards that define the operation of hardware devices. These protocols are often developed by standards organizations like the IEEE (Institute of Electrical and Electronics Engineers) and are made available publicly. Examples include:

• Ethernet standards (IEEE 802.3): Specifications for wired network connections, including aspects like cable types, signaling, and connector types.
• Wi-Fi standards (IEEE 802.11): Define wireless networking techniques.

Open-source design principles at this layer focus on transparency, modifiability, and free distribution of hardware designs. These principles allow for collaborative improvements, cost reductions, and increased innovation in hardware development.

5. Open Firmware for OSI Layer 1 Devices

Open firmware refers to the software that operates on the hardware devices at the Physical Layer, controlling their behavior. While firmware is more commonly associated with higher-layer functions, there are projects aimed at developing open-source firmware for devices that could be considered part of Layer 1, such as:

• OpenWrt: Primarily for routers and network devices, OpenWrt provides a fully writable filesystem and thus can be seen as touching upon Layer 1 through the control of physical interfaces and modulation schemes.
• U-Boot: A universal bootloader, often used in embedded devices to initialize hardware before loading the operating system. It has wide applicability, including in devices operating at the Physical Layer.

Although not every project is exclusively focused on OSI Layer 1, the openness in firmware development for networking devices significantly impacts the flexibility, security, and functionality of physical network components.