The Camera Monitor System (CMS), commonly referred to in the industry as electronic rearview mirrors, replaces traditional optical rearview mirrors with a combination of cameras and monitors. In this display mode, images captured by external cameras are processed and displayed on in-cabin screens, while also integrating functions such as blind-spot warning and obstacle alerts.

Scope of Application:
The standard “GB 15084-2022: Motor Vehicles - Devices for Indirect Vision - Requirements of Performance and Installation” specifies the technical requirements, test methods, installation requirements, and conformity of type for devices for indirect vision on category M and N motor vehicles, as well as category L motor vehicles with at least a partially enclosed cab.

Mirror Types and Field of View Requirements: (GB 15084-2022 6.5)
The types of devices for indirect vision and their field of view requirements are as follows:
a) Class I, providing the interior rear view;

Field of view requirements:
The driver shall be able to see, on a level road surface, an area centered on the longitudinal median plane of the vehicle, at least 20 m wide, extending from 60 m behind the driver's eye point to the horizon (see the shaded area in the figure).

b) Classes II and III, providing the main exterior rear view;
Class II Main Rearview Mirror

Field of view requirements:
Class II device on the driver's side
The driver shall be able to see, on a level road surface, an area 5 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the driver's side, extending from 30 m behind the driver's eye point to the horizon. Additionally, the driver shall be able to see an area 1 m wide, starting from a point 4 m behind the vertical plane passing through the driver's eye points, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle (see the shaded area on the driver's side in the figure).

Class II device on the passenger's side
The driver shall be able to see, on a level road surface, an area 5 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the passenger's side, extending from 30 m behind the driver's eye point to the horizon. Additionally, the driver shall be able to see an area 1 m wide, starting from a point 4 m behind the vertical plane passing through the driver's eye points, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle (see the shaded area on the passenger's side in the figure).

Class III Exterior Rearview Mirror
Field of view requirements:
Class III device on the driver's side
The driver shall be able to see, on a level road surface, an area 4 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the driver's side, extending from 20 m behind the driver's eye point to the horizon. Additionally, the driver shall be able to see an area 1 m wide, starting from a point 4 m behind the vertical plane passing through the driver's eye points, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle (see the shaded area on the driver's side in Figure 8).

Class III device on the passenger's side
The driver shall be able to see, on a level road surface, an area 4 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the passenger's side, extending from 20 m behind the driver's eye point to the horizon. Additionally, the driver shall be able to see an area 1 m wide, starting from a point 4 m behind the vertical plane passing through the driver's eye points, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle (see the shaded area on the passenger's side in Figure 8).

c) Class IV, providing the wide-angle exterior view;
Field of view requirements:
Class IV device on the driver's side
The driver shall be able to see, on a level road surface, an area 15 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the driver's side, extending from at least 10 m to 25 m behind the driver's eye point. Additionally, the driver shall be able to see an area 4.5 m wide, starting from a point 1.5 m behind the vertical plane passing through the driver's eye points, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle (see the shaded area on the driver's side in the figure).

Class IV device on the passenger's side
The driver shall be able to see, on a level road surface, an area 15 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the passenger's side, extending from at least 10 m to 25 m behind the driver's eye point. Additionally, the driver shall be able to see an area 4.5 m wide, starting from a point 1.5 m behind the vertical plane passing through the driver's eye points, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle (see the shaded area on the passenger's side in the figure).

d) Class V, providing the close-proximity exterior view;
Field of view requirements:
The driver shall be able to see, on a level road surface, the area bounded by the following vertical planes [see the shaded areas in Figures a) and b)]:
a) A plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the cab on the passenger's side;
b) A plane parallel to plane a), located 2 m outwards;
c) A plane parallel to the vertical plane passing through the driver's eye points, located 1.75 m behind it;
d) A plane parallel to the vertical plane passing through the driver's eye points, located 1 m in front of it. If the distance between the transverse vertical plane at the front of the vehicle's bumper and the vertical plane passing through the driver's eye points is less than 1 m, the transverse vertical plane at the front of the bumper shall serve as the parallel plane;
If the field of view given in Figures a) and b) can be obtained through Class IV and Class VI devices, the installation of a Class V device is not mandatory.

For vehicles where any part of the Class V mirror or its mounting bracket, in any adjustment position, has a height above the ground greater than 2.4 m, the driver shall be able to see, on a level road surface, the area bounded by the following vertical planes (see the shaded areas in Figures c and d):

• Laterally, a plane parallel to the aforementioned plane, located 4.5 m outwards;
  
• Rearwards, a plane parallel to the vertical plane passing through the driver's eye points, located 1.75 m behind it;
  
• Forwards, a plane parallel to the vertical plane passing through the driver's eye points, located 3 m in front of it. This field of view may be partially provided by the front view device.
  
• This field of view may be provided by a combination of Class IV, V, and VI devices, and does not apply to category M₂ and M₃ vehicles.
  

e) Class VI, providing the front view;
Field of view requirements:
The driver shall be able to see, on a level road surface, the area bounded by the following vertical planes (see the shaded area in the figure):
a) A transverse vertical plane passing through the foremost point of the vehicle body;
b) A transverse vertical plane located 2 m in front of plane a);
c) A longitudinal vertical plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the cab on the driver's side;
d) A longitudinal vertical plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the cab on the passenger's side, and another longitudinal vertical plane located 2 m outwards from it;
e) In the field of view area defined by the two planes in b) and d), a rounded corner transition with a radius of 2 m is permitted.
This device applies to cab-over vehicles of category N₂ > 7500 kg and category N₃.
If cab-over vehicles of category N₂ > 7500 kg and category N₃ cannot meet the field of view requirements through a Class VI device, other vision assistance systems shall be used, and such systems shall be capable of detecting critical objects within the specified field of view area in the figure.

f) Class VII, providing the view for category L motor vehicles (with at least a partially enclosed cab)
Exterior mirror on the driver's side
The driver shall be able to see, on a level road surface, an area 2.5 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the driver's side, extending from 10 m behind the driver's eye point to the horizon (see the shaded area on the driver's side in the figure).

Exterior mirror on the passenger's side
The driver shall be able to see, on a level road surface, an area 4 m wide, bounded by a plane parallel to the longitudinal median plane of the vehicle and passing through the outermost point of the vehicle on the passenger's side, extending from 20 m behind the driver's eye point to the horizon (see the shaded area on the passenger's side in the figure).