Chapter 2

Using the RADWIN OLBC for RADWIN 2000

Continuing with the RADWIN OLBC for RADWIN 2000 Products:

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Figure 2-1: Link Budget window

 To use the Link Budget Calculator for RADWIN 2000:

1. Choose a band from the drop-down list.

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Figure 2-2: Band selector

2. Choose the Product Series. There are five products from which to choose:

Series

General Description

RADWIN 2000 C

The RADWIN 2000 C Models support asymmetric Ethernet throughput up to 100 Mbps. They are targeted to carrier grade IP Backhaul applications. Asymmetric capacity is automatically allocated to the uplink and downlink according to actual Ethernet traffic and air interface conditions. User settings determine the uplink / downlink capacity during periods of congestion.

The Maximum Information Rate (MIR) may now be set up to 100 Mbps per direction. With TDM services enabled, the link provides symmetric throughput up to 50 Mbps full duplex.

RADWIN 2000 B

Low form factor ODU with an embedded antenna, additionally connectorized for use with an external antenna. The series provided a low to intermediate solution for backhaul and access applications supporting up to 50 Mbps aggregated net throughput and up to 8 E1/T1.

RADWIN 2000 X

Addresses corporate Access needs operating in 3.3 -3.8 GHz licensed band, supporting up to 20 Mbps aggregate net throughput and up to 3 E1s or 4 T1s.

RADWIN 2000 L

These models are the RADWIN 2000 products from previous releases. They support up to 50 Mbps full duplex net throughput with up to 16 E1/T1 services. Traffic is always symmetric.

RADWIN 2000 PDH

The RADWIN 2000 PDH Models support up to 16 E1/T1 services and up to 10 Mbps Ethernet throughput. They are targeted to Cellular Backhaul applications. Traffic is always symmetric.

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Figure 2-3: Product Series selection

3. Choose the required channel bandwidth:

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Figure 2-4: Channel bandwidth selection

4. For a collocated link choose the RFP. Use the Help button to the right of the RFP selection box for help:

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Figure 2-5: RFP Selector

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Figure 2-6: RFP Selection Guide

For collocated RADWIN 2000 products, you may only use RFP B or E.

5. Enter the required Tx power:

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Figure 2-7: Selecting Tx Power

6. Enter the radio details. Note that Rate is chosen from a drop-down list:

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Figure 2-8: Rate selector

Note

If you choose Adaptive Rate, then the Rate list is unavailable as is the Climate factor list. Both of these quantities are calculated.

The Rate shown, defines the air-interface rate in Mbps. The system operates in TDD mode and has the overhead of the air-interface protocol. Thus, the Ethernet actual throughput is provided by the Ethernet Rate.

Note

For a given air-rate, Ethernet throughput will decrease with increasing range due to propagation delay.

The Fade margin is the minimum required for LOS conditions. For degraded link con­ditions, a larger Fade margin should be used.

The EIRP is given in dBm and Watts.

7. If the required range between the two link sites is known, you may enter it directly. Alternatively, you may enter the latitude and longitude of each site in the link, in which case the distance between them will be calculated and displayed.

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Figure 2-9:  Calculation of distance from site coordinates

If for example, you enter:

Site A: 41.1°N lat 75.2°W Long

Site B: 40.8°N lat 75.0°W Long

and press Set,

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the range will be calculated and displayed:

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Note

You can enter latitude and longitude in degree-minute-second format by typing each coordinate as a space-separated triple like this:

30°12”16’ should be entered as 30 12 16.

Alternatively, if you click View, you are offered a visual link profile in a new browser tab. See Chapter 5 for details.

8. Located to the right of the green Coordinates button is a drop-down list of Climactic C Factor values. It is only available if you choose a non-adaptive rate.

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Figure 2-10: Climactic C Factors

For help about what these mean, click the gsc_00010.png button to the right of the list in Figure 2-10.

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Figure 2-11: Climactic C Factor description

In Figure 2-12 we display a map of the world showing C Factor contours:

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Figure 2-12: World map showing C Factor contours

9. After changing the C Factor, click Calculate to see the changed performance esti­mate.

10. Choose the required services:

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Figure 2-13: Services selector

Choosing Ethernet+T1s or Ethernet+E1s offers a further choice:

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Figure 2-14: Choosing the number of trunks

11. Click Calculate to obtain the required performance estimate.

Note

Placing the cursor in any other calculated field will also update the calculated results.

The Expected Performance parameters are calculated and displayed:

•         Expected RSS - the expected RSS that the RADWIN Manager shows when the RADWIN 2000, RADWIN 5000 & WinLink 1000 ODUs are optimally aligned

•         Services Type - max number of T1 or E1 trunks if “Max Trunks” is selected

•         Ethernet Rate - maximum throughput available for the chosen parameter combina­tion

•         Antenna height for LOS – the minimum antenna height required for line-of-sight operation. It is the sum of the height required for boresight clearance due to the earth’s curvature plus the height required to clear the Fresnel zone

If the expected performance is not suitable for your application, try different parameters and repeat the calculation.