What is OLAN on Boeing 737? (- Onboard Local Area Network)

The onboard local area network (OLAN) on the Boeing 737 is a sophisticated communication system that allows various avionics systems, cabin services, and passenger devices to connect and communicate with each other. OLAN facilitates the integration of different systems and devices on the aircraft, enhancing operational efficiency, passenger experience, and overall safety.

OLAN utilizes Ethernet-based technology to create a network infrastructure within the aircraft, enabling seamless communication and data transmission between different components. This network supports the exchange of important information, such as flight data, system diagnostics, entertainment content, and cabin service requests, among others. It forms the backbone of the aircraft’s avionics and interconnects the flight deck, cabin management systems, in-flight entertainment systems, and other onboard services.

Boeing 737 aircraft feature a comprehensive OLAN solution that is designed to meet the evolving needs of modern aviation. Let’s explore the key components and functionalities of the onboard local area network in more detail.

Key Components and Functionalities of the OLAN

1. Avionics Ethernet Switch

The Avionics Ethernet Switch serves as the central hub of the OLAN, providing the necessary connectivity for multiple devices and systems. It is responsible for routing data packets and managing network traffic within the aircraft. The Ethernet switch ensures reliable and secure communication between the flight control systems, flight management computers, and other avionics components.

The Ethernet switch is designed to handle high-bandwidth data streams and support various data protocols used by different avionics systems. It offers multiple Ethernet ports, allowing devices to be easily connected and establishing a robust network infrastructure. This centralization of network connectivity improves system integration and simplifies maintenance and troubleshooting procedures.

2. Cabin Intercommunication Data System (CIDS)

The Cabin Intercommunication Data System (CIDS) is an integral part of the OLAN on the Boeing 737. It enables communication between the cabin crew, passengers, and different cabin systems while providing real-time monitoring and control capabilities.

CIDS consists of various components, including control panels, public address systems, and passenger information displays. These elements are interconnected through the OLAN, allowing cabin crew members to make announcements, control lighting and temperature, and manage audio/video entertainment systems efficiently. Passengers can also use the network to request services, such as food and beverage orders or assistance from the crew.

3. In-Flight Entertainment System (IFE)

The In-Flight Entertainment (IFE) system leverages the OLAN to provide passengers with a wide array of entertainment options during their flight. It includes seatback screens, overhead displays, and audio systems, all connected via the Ethernet network.

The OLAN supports the transmission of audio and video content to individual passenger screens, allowing them to enjoy movies, TV shows, music, and other multimedia offerings. With the advancement of wireless technologies, passengers can even connect their personal devices, such as smartphones or tablets, to access the IFE system and stream content directly.

The Boeing 737’s OLAN ensures a seamless and immersive in-flight entertainment experience for passengers, contributing to their overall satisfaction and comfort throughout their journey.

The Importance of the OLAN in Aviation

The onboard local area network plays a crucial role in modern aviation by enabling efficient communication and integration of various systems onboard the Boeing 737 aircraft. Here are some key reasons why the OLAN is of utmost importance:

Enhanced Operational Efficiency

The OLAN streamlines the flow of information between different avionics systems, enabling faster data exchange and facilitating more efficient decision-making processes for the flight crew. Real-time data transmission helps monitor aircraft systems, identify anomalies, and respond promptly, ensuring the safe and smooth operation of the aircraft.

Improved Passenger Experience

The OLAN enhances the in-flight experience for passengers by providing them with a range of entertainment options, seamless connectivity for personal devices, and the ability to order services directly from their seat. Passengers can enjoy a personalized and immersive journey, making their overall travel experience more enjoyable.

Efficient Maintenance and Diagnostics

With the OLAN’s centralized network infrastructure, maintenance and diagnostics become more efficient. The Ethernet-based system enables easy monitoring of various aircraft systems, allowing engineers to identify and address issues proactively. This contributes to reduced downtime, improved aircraft availability, and overall cost savings for airlines.

Furthermore, the OLAN’s robust architecture and redundancy capabilities ensure reliable connectivity and minimize the risk of system failures. This enhances the safety and stability of the aircraft, instilling confidence in both passengers and aviation industry professionals.


The onboard local area network (OLAN) on the Boeing 737 plays a critical role in enhancing communication, integration, and passenger experiences onboard. It enables efficient data exchange between avionics systems, streamlined cabin services, and immersive in-flight entertainment. The OLAN’s Ethernet-based infrastructure ensures reliable connectivity and facilitates efficient maintenance and diagnostics, contributing to the overall safety, operational efficiency, and cost-effectiveness of the aircraft.

As aviation continues to evolve, the importance of advanced communication systems like the OLAN becomes even more significant. By providing seamless connectivity and enabling efficient data exchange, the OLAN helps shape the future of air travel, ensuring a connected and enjoyable journey for passengers.

For More: What is ETC on Boeing 737? (Electronic Temperature Control)