This tutorial provides a guide to installation and alignment of MetroLinq products.
The mounting structure to which the MetroLinq mounting bracket is attached should be plumb (not crooked) and stable to avoid polarization mismatch. Choosing a mounting structure that allows the MetroLinq to be moved one meter vertically or horizontally in the future may be helpful for dealing with multipath issues should they arise.
MetroLinq devices should be properly grounded in compliance with ETSI standards which improves immunity to ESD and other related phenomena. This can be accomplished by either grounding the mounting structure to which the mounting bracket is attached, or attaching a grounding wire directly to the grounding point on the unit.
The first stage of the alignment process is to achieve a course alignment, after which the alignment can be fine-tuned. Course alignment can be achieved visually or by finding the maximum RSSI levels for the 5 GHz back-up connection (if enabled). The procedure is as follows:
1. If using the scope, attach the scope base to the top of the MetroLinq
2. Visually align the units adjusting one axis at a time.
Each scope will vary in accuracy to a different degree. The final position of the scope’s cross-hairs may not be perfectly centered with the device on the opposite side of the link after fine tuning. It is generally helpful to take note of the final position of the cross-hairs after fine tuning for future reference.
After the MetroLinq radios are aligned visually, the alignment can be fine-tuned using real-time RSSI feedback from the built-in aiming mode or the mobile LinqAssist app.
Starting Aiming Mode
Aiming Mode can be activated from the local GUI of the client radio as follows:
1. Login to the client MetroLinq device.
2. Navigate to Radio#1:60 GHz from the WIRELESS menu.
3. Set the device mode to Client.
4. Click on Open Aiming Tool.
5. Set the timer, if needed.
6. Click the START button to start aiming mode.Aiming mode will provide the Local and Remote RSSI values.To stop aiming mode, click on STOP or wait for the timer to expire (if set). Once aiming mode is exited, the 60 GHz link will be restored and ready for use.
The 60 GHz connection will be lost once aiming mode starts
The LinqAssist app, which is available for android and OSX devices, allows mobile devices to receive real-time RSSI feedback via Bluetooth. Before starting LinqAssist, a USB Bluetooth dongle must be inserted into the MetroLinq USB port of the client radio. To use LinqAssist:
1. Open the Linq AssistTM app.
2. Look for the 60Ghz interface MAC address of the MetroLinqTM device into which you’ve installed the Bluetooth USB dongle.
3. Click on the desired radio and the app will display alignment info from the radio.
Fine Tuning The Alignment
Once either aiming mode or LinqAssist has been opened, small adjustments can be made on each axis to fine tune the alignment as follows:
- Loosen the bolts required to adjust the first axis (vertical or horizontal)
Sweep very slowly across the axis from both directions to find the point of maximum signal and lock down the bracket.
Loosen the bolts required to adjust the other (perpendicular) axis.
Sweep very slowly across the other axis from both directions to find the point of maximum signal and lock down the bracket.
For longer links, fine tuning may need to be performed more than once on each side of the link (alternating between sides) to dial in the signal levels. A general guideline for RSSI levels can be obtained from our free LinqPathTM planning tool available on the IgniteNet Cloud.