Справочник Пользователя для Proxim Tsunami MP.11

Tsunami MP.11 Antenna Installation

Notes:

• The RSL must be higher than the Receiver Sensitivity plus the fade margin for a good link. See Table 1 to

have a working link with no excessive errors. The amount of Fade Margin indicates the reliability of the link;
the more Fade Margin, the more reliable the link.

• The path loss must be smaller than the link budget minus the minimum required fade margin. The maximum

ranges cause the path loss plus the fade margin to be the same as the link budget.

The results of this link budget calculation are very important for determining any potential problems during

installation. If you have calculated the expected RSL, you can verify that it has been achieved during installation

and troubleshooting, if necessary.

In the USA and Canada, this model radio can be installed with any gain directional antennas, as there is no

Effective Isotropic Radiated Power (EIRP) limit for the application of these systems for fixed point-to-point

applications in the 5.8 GHz frequency band. In other bands and in other countries, EIRP limits may apply.

In the case of EIRP limits, use the lesser of either (P

out

- L

+ G

) or the EIRP limit within the previous equation.

You should check this equation in both directions to assure legal application. An EIRP limit is the maximum RF

energy that can be transmitted, as measured at the transmitting antenna, and is usually determined by

government regulations.

Proxim’s recommendation is to keep at least 60-70% of the first Fresnel zone free. If the clearance is lower than
this percentage, the link budget and achieved fade margin are affected. Clearances more than 100% of the
Fresnel zone can cause reflections that are 180 degrees out of phase and can cancel out the signal. The Fresnel
zone works in both the horizontal and vertical paths.

The first Fresnel zone size is a list; Proxim’s recommendation is to keep at least 60-70% of this zone free. If the

clearance is lower than this percentage, the link budget and achieved fade margin are affected. Clearances more

than 100% of the Fresnel zone can cause reflections that are 180 degrees out of phase and can cancel out the

signal. The Fresnel zone works in both the horizontal and vertical paths.

Tables for output levels can be found in the Technical Specifications in the Tsunami MP.11 Installation and

Management manual.

Table 1. Examples of Minimum Antenna Cable Loss

Frequency Band

Antenna

Gain

TPC

Setting

Minimum Cable Loss for Data

up to 24 Mbps*

EIRP

Deployment

5.25-5.35 GHz

5.725-5.85 GHz

-6

-10

-6

-10

1.5

9.5

3.5

28.5

29.5

28.5

35.5

USA

USA, PtMP

5.725-5.85 GHz

5.47-5.725 GHz

-6

-10

1.5

9.5

28.5

35.5

41.5

49.5

28.5

29.5

USA, PtP

ETSI

* Note that higher data rates use lower output power, so less cable loss is required to meet the maximum EIRP limit.