Wireless IoT Sensing Devices IoT Wireless I/O Modules Features Wireless Ethernet Interface IEEE 802.11 b/g/n and Wi-Fi The 802.11 specification is a standard for wireless LAN (WLAN) that was ratified by the Institute of Electrical and Electronics Engineers (IEEE) in the year 1997. Like all IEEE 802 standards, the 802.11 standards focus on the bottom two levels the ISO model, the physical layer and link layer. The name Wi-Fi (short for "Wireless Fidelity") corresponds to the name of the certification given by the Wi-Fi Alliance, the group which ensures compatibility between hardware devices that use the 802.11 standard. Due to misuse of the terms, the name of the standard is often confused with the name of the certification. A Wi-Fi network, in reality, is a network that complies with the 802.11 standard. WLAN Infrastructure The WLAN infrastructure is organized by WLAN Access Point (AP) and WLAN Stations. The wireless client, which is the end device like a smart phone, connects to a wireless access point (AP) to join the WLAN network. The wireless server which provides the wireless network, and organizes the network for WLAN stations is called a WLAN access point (AP), or wireless adapter. WLAN APs sometime provides the function of a DHCP server with dynamically assigned IP address for WLAN stations. This kind of AP usually acts a as a network router, so it can also be called a wireless router. HTML5 Web configuration A web interface is the most common interface that can be accessed by most devices. Compared with .NET programmed utilities or mobile apps, a web interface has much less limitations compared to platforms. WISE modules provide web interface configuration in HTML5. By using browsers which support HTML5, like Google Chrome, Mozilla Firefox, IE or Apple Safari, users can access WISE using any devices or platform. The new web configuration interface can automatically change its layout when using different kinds of device, and for mobile devices which have vertical screens, it will automatically adjust the layout to fit the screen of the mobile device and switch to horizontal layout when using a laptop. Before entering the page or web configuration, WISE modules provide an authorization process, meaning that users need to login with different accounts for different authorizations, which ensures the security of the module. Ethernet Architecture WLAN is the easiest interface to implement into an existing Ethernet network, users just need to add an access point to an existing network to extend wireless connectivity. Because all network devices don't need to be from same vendor, it has been widely established for a wide range of different application scenarios. Wireless Operation Mode In general, WISE modules need to stay connected to access points (AP) to be online. Users who want to connect their mobile devices to WISE modules will need to connect to the same AP as WISE modules connect to. In this case, that access point acts as a wireless switch for both Ethernet devices. 2.4 GHz Interface Comparison 2.4 GHz radio band is one of the industrial, scientific and medical (ISM) radio bands. It is the most widely used band for short-range, low power communications systems, which includes Bluetooth, Near Field Communication (NFC), wireless sensor networks (like Zigbee), and wireless LAN (WLAN). WLAN provides most bandwidth and is the widest standard used by vendors. Bluetooth offers low power consumption and is widely applied to mobile devices. The new Bluetooth standard of can automatically avoid radio band interference with WLAN by frequency hopping. ZigBee also provides low energy consumption, and it also has various network topologies. However, ZigBee cannot be used in environments with other 2.4GHz radio wireless devices. Plus, it needs its own gateway to organize the ZigBee network, and it is not compatible with other vendor’s ZigBee devices. Limited AP Mode For configuration or module diagnostics, it is not necessary to have a wireless switch. WISE-4000 series offers another network mode: Limited AP Mode. Users can connect their mobile devices to the WISE module directlywithoutanAP.WhenWISE-4000worksinLimited AP mode, users can find the SSID for and connect to it as a wireless switch. This makes the configuration and diagnostics much easier. Chapter 14 Table of Contents Table of Contents