With the continued development of the Internet of Things, a proprietary "machine-to-machine" network will play a greater role.
Most of the time, the Internet is primarily used to connect people and applications. Now, advances in semiconductor technology allow us to embed powerful processors and network interfaces into everyday objects, which in turn drives the development of the Internet of Things (IoT), where objects communicate with each other and are controlled through the Internet. . At the same time, proprietary "machine-to-machine" networking technology provides the last springboard for many IoT applications. Since each application is different, no single network technology or protocol can support all applications.
Let's take a look at how three proprietary networks with different characteristics meet the specific requirements of IoT generation. All three networks are wireless networks and support a limited distance. However, their applications are different and each network protocol is different to meet these special requirements.
Automakers and the US Department of Transportation are currently developing a set of standards for vehicles to communicate with each other to reduce road traffic accidents.
The goal is that equipment based on these standards will eventually be installed in every car, truck, bus and motorcycle. These standards are known as vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications. IEEE 802.11p or Wireless Access in Vehicular Environments (WAVE) is an important part of this project.
By using WAVE, each car will broadcast its position, speed and direction of travel 10 times per second, and nearby vehicles and roadside infrastructure will receive these broadcasts. Computers installed in the vehicle use these received information to generate an alert to the driver or take action to prevent an accident.
Although 802.11p is based on the IEEE 802.11 standard used by millions of Wi-Fi devices, it operates in different environments and has different design challenges. 802.11p must establish communication between vehicles, and the vehicles may be very close. We know that widely used 802.11 versions (such as 802.11n) require sites to exchange data packets to connect to a particular access point (AP), identified by its unique Basic Service Set Identifier (BSSID). This 802.11p identifier defines an external card BSSID, so no initial packet exchange is required. Each car does not need to establish a connection with a nearby vehicle, it can send its position, speed and direction, and process the data as it is received.
Since a large amount of data is not required to determine position, speed and direction, a high data transmission rate is not required for WAVE. However, data loss caused by reflections from nearby buildings and large trucks and buses poses a challenge. Therefore, WAVE designers use a 10MHz bandwidth channel (a narrower channel than other 802.11 versions) to reduce sensitivity to reflection.
Security is a major issue in V2V projects because of the potential risk of an attacker sending an error message. To this end, IEEE 1609 defines management and security operations for protecting data. According to the standard, vehicles and corresponding infrastructure factors obtain certificates through public key infrastructure to achieve secure operations. At the same time, other research is continuing. These research topics include trying to build protection against distributed denial of service attacks and assessing how to prevent attackers from accessing infrastructure and vehicles. Other issues include strengthening the capacity of certification authorities that support millions of vehicles and roadside infrastructure factors to support V2V and V2I.
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