IEEE Standard for Wireless Access in Vehicular Environments

D.

The IEEE standard that defines wireless access in a vehicular environment is 802.11p. This standard was specifically designed to provide reliable and efficient communication between vehicles and between vehicles and infrastructure in a vehicular environment.

802.11p uses the 5.9 GHz band and operates using a channel bandwidth of 10 MHz. It has a range of up to 1 km and can support data rates of up to 27 Mbps. It uses Orthogonal Frequency Division Multiplexing (OFDM) modulation and has a high level of error correction to ensure reliable communication in a noisy and fast-moving environment.

802.11af, on the other hand, is a standard that defines TV white space (TVWS) wireless networks. These networks use unused frequencies in the TV broadcast spectrum to provide wireless broadband connectivity over long distances.

802.11ac is a standard that defines high-speed wireless local area networks (WLANs) that operate in the 5 GHz band. It can support data rates of up to 7 Gbps and uses Multiple-Input Multiple-Output (MIMO) technology to improve performance.

802.11k is a standard that defines radio resource management (RRM) for WLANs. It provides mechanisms for WLANs to optimize their use of the radio spectrum and to manage interference.

In summary, the correct answer to the question is D. 802.11p.