Aviat Networks Technical Application Note

January 5, 2012

AVIAT NETWORKS TECHNICAL APPLICATION NOTE

ECLIPSE RADIO AIS OPERATION AND EXPLANATION

2 AVIAT NETWORKS January 5, 2012

Aviat Networks Technical Application Note

Eclipse Radio AIS Operation and Explanation

TABLE OF CONTENTS

1. EXECUTIVE SUMMARY .............................................................................................................. 3

2. NORMAL OPERATION OF T1 CIRCUITS IN ECLIPSE RADIOS ............................................. 3

3. LOSS OF INPUT (LOS) OPERATION IN THE ECLIPSE RADIO .............................................. 3

4. TROUBLESHOOTING LOS / AIS ALARMS ............................................................................... 4

5. CONCLUSION ............................................................................................................................. 5

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Aviat Networks Technical Application Note

Eclipse Radio AIS Operation and Explanation

1. EXECUTIVE SUMMARY

This document addresses AIS operation in an Eclipse radio during normal and alarmed conditions.

2. NORMAL OPERATION OF T1 CIRCUITS IN ECLIPSE RADIOS

T1 traffic is provided by the OEM at Site A to the radio at the same location. This T1 traffic is then transmitted across RF to Site B. The radio at Site B sends the T1 traffic to the OEM located at this site (Figure 1). No alarm conditions exist during normal operation.

Figure 1

3. LOSS OF INPUT (LOS) OPERATION IN ECLIPSE RADIOS

If T1 traffic is not provided by the OEM at Site A, the radio at this site will generate a LOS alarm. This alarmed condition can be observed by the operator via the radios interface tool. This same radio will also generate an AIS (Alarm Indication Signal) message. This message will take the place of the absent T1 signal and will be transported across RF to the radio located at Site B. Because the AIS message is generated in response to an external device malfunction, the radio at Site B will not report an AIS alarm indication. However, the radio at Site B will forward the AIS message to the OEM at this location. This OEM device will acknowledge the AIS condition as per its manufacturers design. Refer to figure 2 for additional information.

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Aviat Networks Technical Application Note

Eclipse Radio AIS Operation and Explanation

Figure 2

4. TROUBLESHOOTING LOS / AIS ALARMS

The following troubleshooting guidelines are applicable to the Eclipse and IRU600 product line:

4.1 Trib (#) LOS - Loss of signal on a commissioned tributary. This is a critical alarm.

1. Probable Cause - The failure may be within the attached equipment, the trib cable, or the radio.

2. Recommended Actions Check for alarms on trib-attached equipment, which may indicate loss of signal input

from this source. Check the trib cable and connectors. Check the configuration of the affected trib. Ensure correct line options are selected. Run a loop-back test on the affected trib using an external BER tester. If the test is OK, the problem is in the attached equipment or cabling. If the test fails, replace the DAC/IDU.

3. Additional Information This alarm is raised at the affected end of the link only. For an E1/DS1 trib, AIS will be inserted towards the radio, provided the trib is ticked.

4.2 Trib (#) Output AIS Enabled - Alarm indication signal transmitted on trib(s). This is a warning alarm.

1. Probable Cause AIS has been enabled (forced) on the alarmed trib or tribs using commands in the Portal

System Controls screen. AIS can be forced on E1, DS1, E3, DS3, or STM1/OC3 tribs. 2. Recommended Actions

To remove the alarm, de-select AIS. 3. Additional Information

AIS may be selected to replace the normal signal to indicate to the receiving equipment that there is a transmission interruption at the equipment originating the AIS signal, or upstream of that equipment. In this user-enabled instance, AIS can be used to test traffic or alarm continuity on uncommissioned (non-traffic carrying) tribs, or to send a signal

1.EquipmentFailure

2.LOSAlarmreportedbythisradio.AISmessagegeneratedhere.

3.AISmessagereceivedandforwardedtotheOEMdevice.Noalarmsreportedbythisradio.

4.ThisOEMwillreportanalarmaccordingtothemanufacturersdesign.InthecaseofaLARUSdevice,thisOEMwillreportanAISindicationin the form of a F alarm.

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Aviat Networks Technical Application Note

Eclipse Radio AIS Operation and Explanation

downstream to indicate traffic has been interrupted (for example, a service check is being performed).

For E1, DS1, E3, DS3 tribs, AIS is generated as an unframed, all-ones signal. For an STM1/OC3 trib, AIS selection inserts a PRBS15 pattern (15 bit pseudo-random

bit sequence). The AIS enabled alarm is activated on a per trib basis.

5. CONCLUSION When T1 traffic is absent, the radio will facilitate troubleshooting by generating a LOS alarm on the radio experiencing T1 loss. At the same time, this radio will create an AIS message that will be sent to the remote site, allowing the remote OEM equipment to issue an alarm according to its design.

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Data subject to change without notice.

Eclipse AIS Technical Application Note_Jan 04 2012