MAPL (Maximum Allowable Path Loss)

Last updated on Apr 26, 2023

Maximum Allowable Path Loss (MAPL) is a term used in the telecommunication industry to describe the maximum amount of attenuation that a radio signal can undergo before it becomes unusable. In other words, it is the maximum amount of signal loss that can occur during transmission while still maintaining an acceptable level of signal quality.

MAPL is an important consideration when designing wireless communication systems, particularly for applications such as cellular networks, where it is necessary to ensure that the signal can be received with sufficient strength and quality over a given distance. It is also relevant for other wireless systems such as satellite communication, point-to-point radio links, and other wireless data transmission systems.

In this article, we will discuss the basics of MAPL, how it is calculated, and its significance in the design of wireless communication systems.

Basics of MAPL

The concept of MAPL is based on the fact that when a signal is transmitted from a transmitter to a receiver, it experiences attenuation due to a variety of factors. These factors can include distance, atmospheric conditions, and obstructions in the path of the signal such as buildings, trees, and other physical obstacles.

The strength of a received signal is typically measured in decibels (dB), which is a logarithmic unit that expresses the ratio of the received signal strength to a reference level. In wireless communication, the reference level is often defined as the minimum signal strength required for the receiver to detect and decode the transmitted signal.

In order to ensure that the signal can be received with sufficient strength and quality, a maximum allowable path loss is defined. This is the maximum amount of signal loss that can occur between the transmitter and receiver while still maintaining an acceptable level of signal quality.

Calculation of MAPL

The calculation of MAPL depends on several factors, including the frequency of the transmitted signal, the distance between the transmitter and receiver, the power of the transmitter, and the sensitivity of the receiver.

One commonly used formula for calculating MAPL is the Friis transmission equation, which is given by:

MAPL = (Pt + Gt) - (Pr + Gr) - 20 log (d) - 20 log (f) - K

where:

Pt = transmitter power (in dBm) Gt = transmitter antenna gain (in dBi) Pr = receiver sensitivity (in dBm) Gr = receiver antenna gain (in dBi) d = distance between the transmitter and receiver (in kilometers) f = frequency of the transmitted signal (in megahertz) K = system constant (typically between 32 and 45 dB)

The first term on the right-hand side of the equation represents the power transmitted by the transmitter, taking into account the transmitter power and antenna gain. The second term represents the power received by the receiver, taking into account the receiver sensitivity and antenna gain. The third term represents the attenuation due to distance, while the fourth term represents the attenuation due to frequency.

The last term, K, is a system constant that takes into account other factors such as atmospheric attenuation, multipath interference, and other system losses. The value of K is typically determined empirically based on the specific system being used.

Significance of MAPL

The maximum allowable path loss is a critical parameter in the design of wireless communication systems. It determines the maximum distance over which a signal can be transmitted while still maintaining an acceptable level of signal quality.

If the path loss exceeds the maximum allowable value, the signal quality may degrade to the point where it becomes unusable. This can result in dropped calls, slow data speeds, and other issues that can impact the user experience.

Therefore, the design of wireless communication systems must take into account the maximum allowable path loss to ensure that the system can meet the required level of performance over the intended range of operation.

Conclusion

Maximum Allow Path Loss (MAPL) is a critical factor in the design of wireless communication systems. It determines the maximum distance over which a signal can be transmitted while still maintaining an acceptable level of signal quality. The calculation of MAPL depends on several factors, including the frequency of the transmitted signal, the distance between the transmitter and receiver, the power of the transmitter, and the sensitivity of the receiver.