The US regulatory workfederal Communications Commission (FCC) has implemented its scheduled plan for December 2019: It uses the car consultation PWLAN (IEEE specification 802.11p) after a long response phase the radio spectrum.
Although this only affects the US, but the decisions of the FCC often have groundbreaking character for other regulatory keeps. In Europe, the step is attracting attention, because the auto industry is split in two bearings: some companies, including the world-growing autoconzers Volkswagen, set to 11p, while others prefer the modern mobile technology C-V2X (Cellular Vehicle-to-Everything). C-V2X Grundet on mobile radio techniques LTE and 5G.
No place for two rivals
The main entity for the development of the two methods is the reduction in the number of traffic totes and at all the risk minimization in the strain traffic. For this, vehicles warn each other from hazardous situations such as sudden brakes, unsuitable construction sites or black ice and report when a rescue car crosses the way. 11P and C-V2X are not compatible, and that is the CRUX: research and policies worldwide are convinced that a uniform specification is required for car consultation.
Because the efficiency of networking depends directly on the dissemination and two or more competing techniques reducing their distributions each other. Therefore, the regulatory holders worldwide have reserved only a special wiring belt at 5.9 GHz for the service; In the USA already happened in 1999 (Dedicated Short-Range Communications, DSRC). Unlike mobile communications, however, it was not technologies-neutral, but noticeable at 11p bound.
The FCC has now established: Ongoing projects now have a year time to maximize the range of 5850 MHz to 5895 MHz and to the upper 30 MHz (5895 to 5925 MHz). There is now C-V2X duty. The free 45 MHz is released immediately in unlicited operation in buildings. Practically, this leads to an increase in the Wi-Fi radio. In the US, the 5-GHz band wake up to 160 MHz width, especially the Wi-Fi specification 802.11ax benefits (Wi-Fi 6). In addition, the FCC comments for the use of the 45 MHz in the open air.
USA and EU against 11P
Governments in the US have managed by the car throughout the time differently. For a long time, the implementation of the 11P technique of the auto industry and the in turn of the customer’s demand of the customers is overlooked for a long time (and also elsewhere in the world). However, demand remained largely. Father wanted to make the Obama government PWLAN mandatory. The government under Trump stood against it. The first shot in front of the bug fired the FCC already in 2015. The EU Commission also wanted to make a duty. But the project has stopped a majority of member standards in the summer of 2019, including Germany.
The commonly used designation PWLAN is derived from the IEEE specification 802.11p. In the US, the car network service is run under the name DSRC (Dedicated Short-Range Communications). The EU Commission propulses the car consultation under the title Cooperative Intelligent Transportation Systems (C-ITS), at least until 2019 also based on the 11P technology.
Mobile also not ideal
China, on the other hand, has long been C-V2X and thus LTE and 5G. In Germany, for example, Audi, BMW, Daimler or Deutsche Telekom C-V2X nozzle. VW had already announced a golf with 11p- or PWLAN technology in 2017. But it should take until the summer of 2020 until first golf specimens came to the strain with the car radio. In the test, the vehicle is a positive impression.
Some radio specialists see 11p, however, as a dead end. Especially the weak wireless concept, which does not provide precautions against disturbances while using the radio band. But if two or more vehicles send 11p messages at the same time, it comes to collisions so that the messages are not delivered. The collisions increase with increasing vehicle density. For radio techniques that use a coordinated allocation of radio resources, ie about LTE or 5G, collisions are only available when relieving a radio cell. Because for C-V2x as well as for 11p, the separate range is used at 5.9 GHz, disturbances are excluded by LTE or 5G smartphones.
However, C-V2X is not free of criticism. To achieve the desired short signal transformations, the base stations had to be sustained accordingly. Is open, how expensive that becomes and who finances that. It is also unclear how to achieve a base station cars with foreign SIM cards, so such as a Vodafone-based messages to be delivered to cars with telecom or telephony or even with foreign SIM cards.
The decision of the FCC already fell at the end of October. It is very visible to the middle of November:
Fact Sheet: Modernizing the 5.9 GHz band