Comprehensive Study Notes: Web of Things and Cloud of Things

Overview of Web of Things (WoT)

  • Definition of Web of Things (WoT):     * Used to describe approaches, software architectural styles, and programming patterns that allow real-world objects to be part of the World Wide Web (WWW).     * It provides an Application Layer that simplifies the creation of Internet of Things (IoT) applications.     * Principle of Reuse: Rather than re-inventing completely new standards, WoT reuses existing and well-known Web standards.

  • Core Architectural Objectives of WoT:     * Access: Deals with the access of things to the Internet and ensures they expose their services via Web APIs.     * Find: Provides a way to find and locate things on the Web.     * Share: Ensures that data generated by things can be shared in an efficient and secure manner.     * Integrate: Integrates current services and data offered by things into higher-level Web tools.

Web of Things vs. Internet of Things (IoT)

  • Distinction between the Internet and the World Wide Web:     * The Internet: A term used to identify the massive interconnection of computer networks around the world. It represents the physical connection of the paths between two or more computers.     * The World Wide Web (WWW): The general name for accessing the Internet via HTTP (HyperText Transfer Protocol). It is just one of the connection protocols available on the Internet.

  • Restaurant Analogy:     * If the Internet is a restaurant, the Web is the most popular dish on the menu.     * However, it is the "dishes" (the Web) that make the Internet popular, useful to everyone, and powerful.     * Technically, the Internet is the large container, and the Web is a part within that container.

  • Evolutionary Path:     * Web 1.0: Internet of Documents.     * Web 2.0: Internet of Multimedia.     * Web 3.0: Internet of Things.     * Web of Things (WoT): The current evolution characterized by Web Browsers, Multi-tiered Architecture, and Application Servers.

Two Pillars and Tiers of the Web

  • Three-Tiered Architecture Overview:     * Tier One - User Interface Tier (Client): The client-side interface.     * Tier Two - Connectivity Tier (Application): Contains application logic and the Application Server (AOS). It handles database connectivity.     * Tier Three - Database Tier (Data): Comprises the Database and RDBMS (Relational Database Management System) on the Data Server.

  • Components of the Two Pillars:     * HTML (HyperText Markup Language).     * HTTP (HyperText Transfer Protocol).     * URL (Universal Resource Locator).     * Web Browsers.     * Multi-tiered Architecture.     * Application Servers (including Java-Based Application Servers).

Platform Middleware for WoT

  • Nature and Purpose:     * Communication middleware and platform middleware are closely related.     * Synonyms for Platform Middleware: Application Frameworks or Three-Tiered Application Servers.     * The primary goal is to bring IoT applications to the World Wide Web.

  • WoT/IoT Vision:     * Everyday objects will be connected with each other and the Internet, forming a distributed network with sensing capabilities.

  • Evolution of "Object" Terminology in Software:     * Object-Oriented Design.     * Object-Oriented Software Engineering and Programming.     * CORBA (Common Object Request Broker Architecture).     * DOM (Document Object Model).     * POJO (Plain Old Java Object).     * COM (Component Object Model) & DCOM (Distributed COM).     * OPC (Object Linking and Embedding for Process Control).     * OID (Object Identification).     * SOAP (Simple Object Access Protocol).     * JSON (JavaScript Object Notation).

Unified Multitier WoT Architecture: SOA vs. SODA

  • SOA/EAI (Service-Oriented Architecture / Enterprise Application Integration):     * Focus: Application Integration.     * Primary Goal: Streamline business processes.     * Middleware: ESB (Enterprise Service Bus).     * Key Benefit: High reusability and flexibility.     * Scope: Integrates enterprise software applications like ERP (Enterprise Resource Planning) and CRM (Customer Relationship Management) using protocols like SOAP and XML.

  • SODA/MAI (Service-Oriented Device Architecture / Machine-to-Machine Application Integration):     * Focus: Device/IoT Integration.     * Primary Goal: Connect physical devices to services.     * Middleware: SODA middleware/gateways.     * Key Benefit: Interoperability of things and device connectivity to the cloud.     * Scope: Tailored for the Web of Things; specializes in managing and integrating physical devices and sensors into SOA environments.

  • Protocols and Metadata:     * SOAP: A protocol framework specification for exchanging structured information via XML; usually relies on HTTP, SMTP (Simple Mail Transfer Protocol), or JMS (Java Messaging Services).     * WSDL (Web Services Description Language): Typically describes the services.     * SOAP Protocol: Describes the communication protocols.

  • Device Description Language (DDL):     * Based on XML encodings.     * Classifies devices into three categories: Sensors, Actuators, and Complex Devices.

  • OSGi (Open Services Gateway initiative):     * Known as "The Universal Middleware."     * A module system and service platform for the Java programming language implementing a complete and dynamic component model.

WoT Portals and Business Intelligence (BI)

  • Web Portal Definition: A website that functions as a point of access to information on the World Wide Web, presenting info from diverse sources in a unified way (e.g., Yahoo, AOL, Excite, MSN).

  • Categorization of Portals:     * Horizontal Portals: Cover many different areas.     * Vertical Portals: Focused on one specific functional area. WoT portals are vertical portals.

  • Business Intelligence (BI) and Data Mining:     * Large amounts of IoT data allow for data mining to acquire BI.     * Data mining finds interesting and valid patterns in data.     * Interdisciplinary field involving: Databases, machine learning, pattern recognition, statistics, and visualization.

  • Common BI Functions:     * Extract, Transform, and Load (ETL).     * Reporting, Online Analytical Processing (OLAP), and Analytics.     * Data mining, Process mining, Complex Event Processing (CEP).     * Business performance management, Benchmarking, Text mining, and Predictive analytics.

Cloud of Things

  • Relationship and Categorization:     * IoT is often referred to as Machine-to-Machine (M2M), Connected World, Smarter Planet, or Smart Grid.     * M2M is currently a more popular term than "Cloud Computing."     * Both IoT and Cloud Computing are categorized as forms of distributed computing.     * Cloud computing is considered an enabling technology for the IoT.

  • Mobile Cloud Computing (mCC):     * The market is changing due to "widgets," which are compelling mobile cloud applications.     * Smartphones are becoming thin clients for cloud services.     * Example: Apple's iCloud (announced June $2011$) runs on Amazon Web Services (AWS) and Microsoft Azure IaaS, symbolizing the start of "Cloud Phones."     * Real mCC: Widgets that receive services from the cloud during runtime (e.g., LBS applications, data synchronization, weather forecast, bank clients).

  • Cloud Premise: Data services and architecture reside on servers in a "cloud"; access is independent of the device (PC, Mac, mobile, BlackBerry).

Cloud Middleware and Hierarchy

  • Cloud Hierarchy:     * Software as a Service (SaaS): "Everything as a Service" via PM (Platform Middleware) as a utility IM (Infrastructure Middleware).     * Platform as a Service (PaaS): Includes all Enterprise Middleware, B2B, EAI, and multi-tenant App Servers.     * Infrastructure as a Service (IaaS): Includes Grid Middleware, MSV (Multi-Server Virtualization) Cluster Middleware, SSV (Single System View), and schedulers.     * Foundation: Cloud Platform and Hardware.

  • VAMOS Middleware (IBM):     * Runs modules at the hypervisor level.     * Reduces I/O virtualization overhead by cutting guest/hypervisor switches.     * Application of VAMOS to databases improved performance by up to 32%32\%.

  • Grid and Cluster Middleware Examples:     * Low-level: MPI, Open MPI, PVM (Parallel Virtual Machine), POE (Parallel Operating Environment, IBM).     * Resource/File Systems: MPI-IP, PVFS/GPFS (Parallel Virtual File System), Sector-Sphere, Condor, PBS, LoadLeveler.     * High-level: Globus Toolkit, Gridbus, Legion, Unicore, Beowulf, OSCAR, CAOS, Rocks, OpenMosix.

Cloud Standards

  • Service Models: IaaS, PaaS, SaaS.

  • Deployment Models: Private cloud, Public cloud, Community cloud, and Hybrid cloud.

  • Essential Characteristics:     1. On-demand self-service.     2. Broad network access.     3. Resource pooling.     4. Rapid elasticity.     5. Measured service.