Internet of Things (IoT) - Part 4 (Network Protocols and Architecture)

 
Topics covered
  • IoT Network Protocols
  • IoT Network Architecture

IoT Network Protocols

To understand IoT Networks let’s have a look at this picture.

IoT Network
Figure: IoT Network

In an IoT network the following are some of the technologies.

Wireless Personal Area Network (WPAN) include networks like Zigbee, Bluetooth, 6LowPAN etc.

On a slightly larger wireless network area scale, a Wireless Local Area Network (WLAN) includes Wi-Fi.

On a larger scale, the mobile communication technologies like 2G, 3G,4G and LTE remains. Smartphones and mobile communication systems will be used and they will connect to the base stations and base stations will provide connectivity to a Wide Area Network (WAN) including the internet.

Considering this, we can think of many other options.

Smartphones are equipped with Bluetooth and Wi-Fi, therefore we can think of an IoT network. The most common topology control is the WPAN that is Bluetooth or Near Feild Communication (NFC). The WPAN are connected to a smartphone and the smartphone can bring the signal up using 3G, 4G and LTE using the base station and the base station will connect that to the WAN.

Therefore we get a technology linking on another technology.

Wearable IoT Networks

This is a technology where the preceding explanation is brought into reality.

  • Wearable devices (for example, shoes, watch, glasses, belt, etc.) can be used to detect biometric information.

  • Smart devices collect the information and communicates with the control center and/or medical server using the internet.

    Wearable IoT Networks
    Figure: Wearable IoT Networks

Wi-Fi

  • Wi-Fi is a Wireless Local Area Network (WLAN) technology based on the IEEE 802.11 standards.
  • Wi-Fi Devices.
  • Smartphones, Smart Devices, Laptop Computers, PC, etc.
  • Applications Areas.
  • Home, School, Computer Laboratory, Office Building, etc.
  • Wi-Fi devices and Access Points (APs) have a wireless communication range of about 30 meters indoors.
  • Wi-Fi data rate is based on its protocol type :
  • IEEE 802.11a can achieve up to 54 Mbps
  • IEEE 802.11b can achieve up to 11 Mbps
  • IEEE 802.11g can achieve up to 54 Mbps
  • IEEE 802.11n can achieve up to 150 Mbps
  • IEEE 802.11ac can achieve up to 866.7 Mbps
  • IEEE 802.11ad can achieve up to 7 Gbps

    Wi-Fi IoT Networks
    Figure: Wi-Fi IoT Networks.

Bluetooth

  • Bluetooth is a Wireless Personal Area Network (WPAN) protocol designed by the Bluetooth Special Interest Group (SIG).

  • Replaces cables connecting many types of devices.

  • Mobile phones and headsets.

  • Heart monitors and medical equipment.

  • Bluetooth’s standard PAN range is usually 10 meters (50 m in Bluetooth 4.0).

  • Bluetooth Low Energy (in Bluetooth 4.0) provides reduced power consumption and cost while maintaining a similar communication range.

  • Bluetooth 2.0 + EDR can achieve up to 2.1 Mbps.

  • Bluetooth 3.0 + HS can achieve up to 24 Mbps.

  • Bluetooth 4.0 can achieve up to 25 Mbps

    Bluetooth IoT Network
    Figure: Bluetooth IoT Network

IEEE 802.15.4 Standard

  • Low-cost, low-speed, low-power Wireless Personal Area Network (WPAN) protocol.

  • IEEE 802.15.4 applications.

  • ZigBee, 6LoWPAN (IPv6 over low-power Wireless Personal Area Networks), Highway Addressable Remote Transducer (WirelessHART ), Radio Frequency for Consumer Electronics (RF4CE), Microchip Wireless Protocol (MiWi), and ISA100.11a

    Zigbee layer in OSI Model
    Figure: IEEE 802.15.4 and Zigbee layer in OSI Model.

ZigBee

  • Supported by the ZigBee Alliance.

  • Provides IEEE 802.15.4 higher-layer protocols required for low-powered radio systems.

  • IEEE 802.15.4 defines the physical and MAC layers.

  • ZigBee provides the application and network layer protocols.

  • ZigBee works well in isolated network environments.

    Zigbee Network
    Figure: Zigbee Network

A Zigbee network is made up of a Coordinator (C) that is required to establish a network connection. Coordinator ‘C’ establishes a PAN, a router (R), that provides the network connection to the end devices and End Device (E) that are the IoT devices connected to the network.

The following describes a IPv6 over Low-power Wireless Personal Area Networks (6LoWPANs):

  • Supports IPv6 packets over IEEE 802.15.4 WPANs.

  • Enables IPv6 IoT wireless network support.

  • Low power design included.

  • Good for battery-operated IoT devices.

  • 6LoWPAN is an Internet Engineering Task Force (IETF) standard that uses the IEEE 802.15.4 WPAN technology.

    6lowPAN
    Figure: 6lowPAN

In the 6LoWPAN node, Bluetooth smart devices can connect to the internet over Bluetooth Smart using a border router. The border router acts as a device connected to the internet and provides access for the nodes to the internet.

Z-Wave

The Z-Wave protocol is an interoperable, wireless, RF-based communications technology designed specifically for control, monitoring and status reading applications in residential and light commercial environments.

  • Low-powered RF communications technology that supports full mesh networks without the need for a coordinator node.

  • Operates in the sub-1GHz band, impervious to interference from Wi-Fi and other wireless technologies in the 2.4-GHz range (Bluetooth, ZigBee, etc.).

  • Designed specifically for control and status apps, supports data rates of up to 100kbps, with AES128 encryption, IPV6 and multi-channel operation.

    wave applications
    Figure: Z – wave applications

UDP

  • Data networking protocol.

  • Incorporated under the architecture of TCP/IP protocol.

  • UDP is robust and that is why TCP/IP has mainly standardized UDP for real-time data transfer.

    IoT Network Layers of OSI model
    Figure: IoT Network Layers of OSI model

In the diagram below, we get a clear differentiation of IP Suite and IP Smart Object (IoT) suite.

clear differentiation of IP Suite

IoT Network Architecture

Autonomous Network Architecture

  • Autonomous networks are not connected to the public networks. However, it does not mean that internet access is forbidden. It is possible via a gateway if required.

  • While designing autonomous networks, though not mandatory, an IP protocol suite is still commonly adopted due to its scalability and flexibility.

  • The large address capacity provided by IPv6 is required in most cases.

Example: Autonomous information collected by the parking sensor due to the occupancy of parking slots in a wireless manner and sent to the control center.

Autonomous Network Architecture
Figure: Autonomous Network Architecture

Ubiquitous Network Architecture

  • Smart objects or "things" network are a part of the internet.

  • Using the internet gateway, authorized users will have access to the information provided by smart objects networks, either directly fetching from the device or by means of intermediate servers.

  • The servers act as a sink to collect data from each object.

  • Features

  • Multitier: The network architecture is hierarchical, comprised of both multi-access networks and wireless multi-hop networks.

  • Multiradio: It is uncommon theses days to have a number of radio access technologies available to connect to the internet, either covering the same or complimenting geographical areas. These networks could be WLAN, WiMAX, macro-cellular, femto-cellular or even ad-hoc. The synergy and integration of multiple networks in multi-access and multi-operator environment introduces new opportunities for better communication channels and an enhanced quality of provided applications and services.

Examples

Structural Health Monitoring:
Monitoring the health of any structure, large or small, like buildings, bridges and so on. Passive wireless sensors are embedded within a concrete structure that sends radio signals of suitable amplitude and phase characteristics periodically using radio frequencies. The data collected from these sensors are then analyzed to detect anomalies.

Ubiquitous Network Architecture
Figure: Ubiquitous Network Architecture

That’s all for this article. Hope this was helpful and you enjoyed reading!!

 
References: