The combination of IoT and Big Data has given rise to streaming analytics, which processes and analyzes data in real-time. This enables immediate decision-making based on the data generated by IoT devices.

Blockchain integration in IoT is especially beneficial for maintaining data integrity. Blockchain's tamper-proof nature ensures that data remains unaltered, enhancing the trustworthiness of information in IoT applications. Device Availability, Real-time Data Processing, and Energy Efficiency are important but not the primary focus of blockchain integration in IoT.

The integration of IoT in agriculture, where sensors monitor soil moisture and trigger irrigation systems, is an example of Edge Computing. In this scenario, IoT sensors at the "edge" (in the field) collect data, analyze it locally, and make real-time decisions (turning on irrigation) without sending all data to a centralized server. Edge computing enhances efficiency and reduces latency in agriculture applications.

RTOS stands for Real-Time Operating System. It's an operating system intended to serve real-time applications, where processing must be done within specific time constraints.

A common security challenge faced by IoT devices is inadequate authentication. Many IoT devices lack robust authentication mechanisms, making them vulnerable to unauthorized access and potential security breaches. Proper authentication is essential for protecting IoT devices and the data they handle.

One of the main challenges in deploying WSN in IoT is the limited battery life of sensor nodes. This is because many sensor nodes are often deployed in remote or inaccessible locations, making it challenging to replace or recharge their batteries.

In a typical IoT system, the Data layer is responsible for processing and analyzing the collected data. This layer is crucial for handling, storing, and making sense of the data gathered from various sensors and devices in the IoT ecosystem.

FreeRTOS is a real-time operating system (RTOS) kernel that is event-driven and widely used in embedded systems due to its low resource requirements and real-time capabilities.

In advanced IoT applications involving autonomous vehicles and traffic signals, a Publish-Subscribe (Pub/Sub) communication model is most suitable. This model allows multiple devices (vehicles) to publish information (their status, location) to a central hub (traffic signals) and subscribe to updates from others. It's a scalable and efficient way for real-time interaction, enabling vehicles to receive timely traffic information.

In IoT, differential privacy is a technique used to protect the privacy of individual data in a dataset. It adds noise or perturbation to data in a way that makes it challenging to identify individual data points while still allowing useful insights to be derived from the dataset. This is crucial for preserving the privacy of IoT data, especially when dealing with sensitive information.