In the previous tutorial, various physical and data link layer protocols developed for LPWAN were discussed. In this tutorial, protocol stacks developed for Personal Area Network (PAN), Home Area Network (HAN) and Local Area Network (LAN) will be discussed.
In this tutorial, the following protocol stacks and standards are discussed –
1) IEEE 802.15.4e
7) IEEE 802.11.ah
10) ISA 100.11a
1) IEEE 802.15.4e – IEEE 802.15.4 is a physical and MAC layer protocol developed by IEEE 802.15 Group for Low Power Wireless Personal Area Networks. This protocol stack operates on license free frequency bands like 868 to 868.6 MHz in Europe, 902 to 928 MHz in United States and 2400 to 2483.5 MHz in other parts of the world. This protocol stack has been developed for short range communication between low power devices. Such data communication is characterised by low data rates, limited bandwidth and low transmission power. The devices as well as the transceivers are battery operated and must need a battery replacement over long time.
In this standard, IOT devices can be connected in a star topology or peer to peer topology. The peer to peer topology is usually preferred when the network coverage has to be extended using multi hop routing. Because of the limited transmission range, the devices have to operate cooperatively in order to enable multi hop routing over longer distances. As a result, the packet size is limited to 127 bytes only, and the rate of communication is limited to 250 kbps.
The coding scheme in IEEE 802.15.4 has built in redundancy, which makes the communication robust, allows to detect data losses, and enables the retransmission of lost packets. The protocol also supports short 16-bit link addresses to decrease the size of the header, communication overheads, and memory requirements.
The IEEE 802.15.4 standard is basis for many other LAN and PAN protocol stacks as well like Zigbee, WirelessHART, Thread and MiWi.
2) Zigbee – Zigbee is an IEEE 802.15.4 standard based protocol stack developed primarily for industrial use. It operates at 2.4 GHZ frequency range and have data rates up to 256 Kbps. A Zigbee based network can be designed in star, peer to peer or cluster tree topology. There can be maximum 1024 nodes in a network with total network coverage limited between 100 and 200 metre.
Zigbee comes available in two stack profiles – Zigbee PRO and Zigbee Remote Control. These stack profiles are different implementation of Zigbee network. In either stack profile, there are three types of devices in a Zigbee network: FFD (Fully Functional Device), RFD (Reduced Functional Device), and one Zigbee coordinator. A FFD node can additionally act as a router. Zigbee uses 128 bit AES (Advanced Encryption Standard) encryption to secure data transmission among connected devices. The latest version of Zigbee is Zigbee 3.0. The recent version has unified different stack profile standards to a single standard.
3) WirelessHART – Developed from Time Synchronized Mesh Protocol (TSMP) by Dust network, Wireless Highway Addressable Remote Transducer Protocol (WirelessHART) is standard protocol designed for wireless sensor networks. This protocol stack is widely used for industrial automation applications. This industrial automation protocol has been specially designed to manage process measurement, industrial asset management and process control. It is a robust and interoperable wireless standard based on IEEE 802.15.4 standard. It operates at 2.4 GHz frequency and has several security features at different levels of network architecture to provide a secure, reliable and robust M2M communication in an industrial scenario. It uses Time Division Multiple Access (TDMA) technique at MAC layer featured with advanced encryption standards.
4) Thread – Thread is a IPv6 based network layer protocol which uses IEEE 802.15.4 standard at physical and MAC layers. It was developed by Thread Group for Home Automation Networks (HAN). It is based on IEEE 802.15.4, IPv6 and 6LoWPAN standards and operates at 2.4 GHz frequency at physical layer (PHY). There can be maximum 250 nodes in a thread network and data is secured by implementation of various authentication and encryption techniques.
5) MiWi – MiWi is a proprietary wireless protocol developed by Microchip Technology for Wireless Personal Area Network (WPAN). It is based on IEEE 802.15.4 standard and is developed for interconnecting low power devices in short range with communication at low data rates up to 250 Kbps. At physical layer, it operates at a frequency of 2.4 GHz.
6) Z-Wave – Z-Wave is more of a de facto standard than a traditional one approved by a standards body or industry consortium. It is a wireless communication protocol used primarily for home automation networks (HAN). Z-wave operates at 908.42 MHz frequency in US and 868.42 MHz in Europe. It works on mesh networking topology so it can support up to 232 nodes on a single mesh network. The network coverage of Z-Wave is limited to 30 Metre and data rates can be up to 100 Kbps. Unlike multiple vendors for technologies like BLE, Zigbee, WirelessHART, Sigma Designs is the only vendor providing Z-Wave transceivers.
7) IEEE 802.11.ah – IEEE 802.11.ah is Wi-Fi variant operating at Sub-1GHz license free frequency bands. The Wi-Fi Alliance has introduced the term “Wi-Fi HaLow” as the designation for products incorporating IEEE 802.11.ah technology. This protocol stack will allow connecting low power devices with an extended coverage similar to a Wi-Fi network. The extended coverage for this standard could be up to 1 Km for a single station through use of multiple relays. The standard allows 1, 2, 4, 8 and 16 MHz wide channels according to license free bandwidth available in a country. The standard allows using BPSK, QPSK and QAM modulation techniques for data transmission with maximum data rates up to 347 Mbps. The transceivers in this protocol stack are battery operated that usually need a battery replacement in weeks.
8) EnOcean – EnOcean (Energy Harvesting Wireless Technology) is a wireless protocol stack that operates at 868 MHz frequency in Europe and 315 MHz frequency in United States. It is a physical and MAC layer protocol with network coverage up to 30 metre in indoor and 300 metre in open areas. The standard has been developed to network battery less wireless sensors in a Personal Area Network (PAN).
9) Eddystone – Developed by Google, Eddystone is BLE based beacon messaging protocol in a short range distance. The protocol stack can be used for data communication with mobile devices (both android and IOS) and driving sensor data within a network.
10) ISA 100.11a – Developed by International Society of Automation (ISA), ISA 100.11a is a wireless protocol for industrial automation. The protocol has been designed for non critical process control, monitoring and alert application in an industrial scenario. The standard defines all seven layers of OSI model including protocol stack for physical and MAC layers.
11) ANT – Developed by ANT Wireless, ANT is a proprietary physical and MAC layer protocol designed for Wireless Sensor Networks (WSN). Based on 2.4 GHZ ISM band, the ANT can have a network coverage up to 100 Metre. This protocol stack is currently used for Personal Area Networks (PAN) in Health and Fitness Verticals. The company is working on adapting the protocol to suit other PAN applications as well like home automation, office and industrial automation.
12) INSTEON – INSTEON is an RF protocol stack developed for Home Automation Networks (HAN). It uses a dual mesh topology where home automation based IOT devices are networked as independent peer devices. The protocol uses frequency shift keying for RF messaging among devices. The devices can communicate with each other any time whenever required.
13) DiGiMesh – DiGiMesh is proprietary protocol standard developed by DiGi International. It is a wireless protocol stack for mesh networking topology suitable for low power personal area network (PAN) applications.
14) HomePlug – Developed by HomePlug Power line Alliance, HomePlug is a physical and network access protocol designed for Home Automation Networks (HAN). It comes available in three variants – HomePlug-AV, HomePlug-AV2 and HomePlug-GP.
15) G.9959 – Developed by ITU, G.9959 is a network access protocol stack designed for wireless networking of low power devices in a Personal Area Network (PAN). There can be maximum 232 nodes in a network having half duplex communication at low bandwidth and low data rates.
In the next tutorial, RFID based protocol stacks will be discussed.
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