Page 318 - From Smart Grid to Internet of Energy

Internet of things for smart grid applications Chapter 7 283

On the other hand, Chinese Industrial Wireless Alliance has introduced
another industrial standard entitled Wireless network for Industrial
Automation-Process Automation (WIA-PA) almost at the same time in 2010.
A regular WIA-PA network associates star and mesh topologies to compose
a hierarchical network. The mesh topology includes router and gateways, while
router and field devices compose star topology. The components of WIA-PA
networks are same with WirelessHART where the field devices are integrated
at industrial stages to obtain and to transmit the data. ISA100.11a has been pre-
sented by International Society of Automation (ISA) in 2009 and has been
approved as IEC 62734 standard by IEC in 2014. Despite the previous wireless
standards, ISA100.11a is aimed to be a new approach with wider coverage and
broader connectivity features. The devices are spread into two main groups as
field devices and infrastructure devices in ISA100.11a that data acquisition
devices, routers, and mobile devices are defined as field devices and backbone
routers, gateways, and security devices are accepted as infrastructure devices
[42, 53].
The improvements of TSCH and DSME approaches brought by IEEE
802.15.4e promoted IPv6 utilization in industrial networks. 6TiSCH is a crucial
standard performing IPv6 communication over TSCH by interconnecting MAC
layer and network layer. IEEE 802.15.4e is not capable to fill the gap between
scheduling and managing the networks traffic that is accomplished by 6TiSCH
Operation Sublayer. Thus, the top stack of 6TiSCH enables IPv6 that allows
converting long 6LoWPAN packets to short IEEE 802.15.4. Three major open
source wireless devices; OpenWSN, Contiki, and RIOT, support 6TiSCH to
implement WSN and wireless communication infrastructure. The features
and differences of industrial IoT (IIoT) protocol architectures are illustrated
in Fig. 7.7 regarding to the wireless industrial standards. The layer structure
is comprised by considering OSI seven-layer structures where some standards
do not include respecting protocols are left blank.
Security and privacy issues should be taken into consideration at the adop-
tion stage of IoT devices. The security environment includes all sides of infra-
structure as users, things, technological system, and processes. The PHY and
MAC layer security is related to communication devices where IEEE
802.15.4 is prominent standard enabling security services operating at MAC
layer with various encryption methods. The 32-, 64-, and 128-bit Advanced
Encryption Standard (AES) keys are used to increase security in Cipher Block
Chaining (CBC) mode that generates a Message Integrity Code (MIC) or Mes-
sage Authentication Code (MAC) inserted to the transmitted data. The security
mode AES keys are identified as AES-CBC-MAC-32, AES-CBC-MAC-64 and
AES-CBC-MAC-128 at MAC layer. These keys prevent the vulnerabilities to
integrity and authentication attacks. Cipher blocking and counter modes are
associated to increase confidentiality of IEEE 802.15.4 standard at link layer
transmission. The associated encryption modes are defined with CBC-MAC
AES/CCM and AES keys are titled as AES-CCM-32, AES-CCM-64 and
AES-CCM-128 with different heap sizes and encryption levels.