Answer:
Option D: UNII-3
Explanation:
According to the 802.11 standard, 23 20MHz wide channels are defined in 5 GHz specturm. Each channel is 20MHz apart and they are separated into three Unlicensed National Information Infrastructure (UNII) bands. 802.11a/n/ac wireless devices can operate within these bands. In United States, UNII-3 is the upper UNII band that spans from 5.725 GHz TO 5.825 GHz and therefore it is the band that access point is operating. UNII-3 is not used in Europe countries for wireless communication.
Answer:
The system call is the programming way for executing the requesting the services in the program from kernel in the particular operating system.
The main purpose of the system call in the operating system is that it basically provide the different types of the services to the users by using the API (Application program interface) system.
It basically provide the interface for allowing the users to request the services between the operating system and a processor. In the linux there are basically three types of system call are as follows:
D. A spike of electricity. They are fast and have a short duration.
