# The Latest Advances in Wireless Communication in Aviation, Wind Turbines and Bridges
## 4 WSN Systems in Different Applications: Aerospace, Bridge Structures, and Wind Turbines
### WSN in Aerospace
#### 4.1.3 Selected Wireless Communication Protocols Used in Aviation  
The Avionics data and communication network (also known as ADCN) is mainly comprised of three types of systems (Time Critical: Avionics network; High Performance: Aircraft and Cabin Operations; Open World: in-Flight Entertainment). The highest level of criticality is critical, whereas high performance and open-world correspond to medium and lowest levels. In the case of open-world and high-performance systems, increasing bandwidth utilization is one of the main constraints, while predictable behavior and timing guarantees are not necessarily a fundamental design issue. Within the field of open-world systems, in [34], the authors referred to the conducted simulations and experiments with the use of standard wireless technologies for an In-Flight Entertainment Network (IFE). The results obtained for heterogeneous architecture based on Ethernet and Wireless USB technologies are promising in QoS. For high-performance systems, authors in [34] referred to tested Ultra WideBand technology for in-cabin communication with optimized resource allocation, and average communication latency was achieved with the use of simulation. The following standards apply in data and communication networks (ADCN):  
* AFDX(IEEE 802.11e) makes use of a unique protocol in order to provide deterministic time management and redundancy, ensuring secure and reliable communication of critical and non-critical data. AFDX(r) communication protocols have been developed from commercial standards (Etherther MAC addressing IEEE802.3, IP Internet Protocol, UDP user datagram) in order to obtain the required deterministic behavior for avionics applications. Virtual Linked Terminal Systems (or LRUs) communicate with traffic shaping through bandwidth allocation gaps (BAG). AFDX(r) data transmissions are used on the following aircraft: Airbus A380/A350/A400M, Boeing B787 Dreamliner (ARINC 664), ARJ21, and Super jet 100. AFDX(r)/ARINC 664P7 is used as the core for all systems, such as flight control systems, cockpit avionics, air conditioning, power equipment, fuel systems, landing gear, and more [35]. * The CAN bus is a 1 Mbps data bus that works in accordance with an event-triggered paradigm where messages are transmitted with the use of a priority-based access mechanism. Figure 5: Graphical representation of different wired sensors distribution all over the aircraft [33]. anism. CAN bus operates by using a producer/consumer communication scheme which is based on a unique identifier per message type. The CAN messages are broadcast on the bus; then, each CAN equipment will filter the consumed data based on the CAN identifier. The collisions on the bus are solved following a CSMA/CR protocol (Carrier Sense Multiple Access/Collision Resolution) by the bit arbitration method. The CAN frame comprises a payload of up to 8 bytes and an overhead of 6 bytes because of the different headers and bit stuffing mechanism [36]. * The ARINC 429 and MILSTD 1553B are communication standards used in both military and commercial aviation. The ARINC 429 connects LRUs onboard Boeing 737 and other civil aircraft with the use of distributed avionics architectures. The MIL-STD 1553B is applied in most military aircraft for critical flight control and various mission systems. Both of them are half-duplex communication standards. The ARINC 429 connects the LRU. The MIL-STD 1553B connects multiple devices via a common bus via a point-to-point wiring scheme. They are now used in manufacturing and space aircraft; however, certain shortcomings in modern aircraft performance have resulted in the adoption of extended and modified versions of these standards [37]. * ARINC 653 is a specification for an application executive used for integrating avionics systems on modern aircraft. This specification is aimed at enforcing fault containment, and preventing fault propagation from one partition to another, which eases the application's life cycle verification, validation, as well as certification procedures.