L-Band Frequency Change

Changes to L-Band Coverage – December 19, 2018

From December 19, 2018, the geographic region covered by AORE beam (15.5W longitude) will be replaced by AORW beam (54W longitude), as part of the planned AORE satellite decommission. AORW broadcast power has already been increased and will continue at the levels, until the AORE replacement.

Users should not expect any performance degradation in their L-Band reception or their positioning, with the above change. The change does not require any new firmware updates. Receivers with auto assignment require no manual intervention.

Receivers that are manually configured to track the AORE beam, must switch to either AORW or 25E beam after December 19, 2018.

Please visit this page or sign up here to receive the latest information on the L-Band frequency updates.

Beam Name Satellite Position (Longitude) Frequency (MHz) Updates
98W 98.0 West 1545.8650 No change.
AORW 54.4 West 1545.8450 Increased power, now covers AORE region.
AORE 15.5 West 1545.8550 Signal turned off on December 19, 2018.
25E 25.0 East 1545.8250 No change.
IOR 64.5 East 1545.8650 Increased power.
143.5E 143.5 East 1545.8350 No change.
POR 178.0 East 1545.9050 No change. 

Please visit the TerraStar coverage page, to find out the visible beams in your region. https://www.novatel.com/products/terrastar-gnss-corrections/terrastar-coverage-map/

For more information or assistance, please contact NovAtel support.

Email: support@novatel.com

Phone:
1-800-NovAtel (1-800-668-2835) for North American Access
1-403-295-4900 for International Access

The following section addresses the frequently asked questions regarding the L-Band updates.

Frequently Asked Questions

1. What is changing with TerraStar?

2. When will the L-Band frequency change occur?

3. Why are the L-Band frequencies changing?

4. What services will be affected by the L-Band frequency change?

5. Who will be affected by the L-Band frequency change?

6. Is there a need for a firmware update?

7. What firmware versions are compatible?

8. How can I ensure my receiver works without any issue during the L-Band frequency change?

9. How does the L-Band frequency get updated in the receiver?

10. How can I verify the L-Band Frequency change in the receiver?

11. What happens if the receiver was never turned on during the frequency change period?

12. My receiver is still tracking the beam on the old frequency?

13. I don't have an active subscription; can the receiver track the new L-Band frequency?

14. Where can I get more information or assistance?

1. What is changing with TerraStar?

The L-Band frequencies used by all seven satellites (beams) to broadcast the correction signals to NovAtel receivers are changing. The beam name and the baud rate will not change. The correction messages will remain the same but will be broadcast on new frequencies.

2. When will the L-Band frequency change occur?

The L-Band frequency change will happen in two stages. The schedule and the corresponding beam turn on dates (for new frequency) and turn off dates (on old frequencies) are summarized in the table below.

 

Beam Name

New Frequency (MHz)

Turn on Date (New Frequency)

Old Frequency (MHz)

Turn off Date (Old Frequency)

STAGE 1

98W

1545.8650

March 15, 2018

1539.9025

May 15, 2018

AORE

1545.8550

March 16, 2018

1539.9825

May 16, 2018

143.5E

1545.8350

March 17, 2018

1539.9925

May 17, 2018

STAGE 2

25E

1545.8250

August 15, 2018

1539.8825

October 15, 2018

AORW

1545.9550

1545.8450

August 16, 2018

1539.8925

October 16, 2018

IOR

1545.8650

August 17, 2018

1539.9025

October 17, 2018

POR

1545.9050

August 18, 2018

1539.9425

October 18, 2018


To confirm which beams, cover your area of operation, please visit the TerraStar coverage map: https://www.novatel.com/products/terrastar-gnss-corrections/terrastar-coverage-map/The correction signals will be broadcast on both old (current) and new frequencies for a period of 8 weeks, to allow enough time for receivers operating in those areas to transition seamlessly from the old to new frequencies and to update the receiver’s stored beam table. After 8 weeks, the old frequencies will be turned off and only the new frequencies will be used. Any NovAtel receiver that was not powered on during the 8-week transition period will need to be manually assigned to the new frequency to get the correction signal and to update the L-Band beam table (See ASSIGNLBANDBEAM command).

3. Why are the L-Band frequencies changing?

INMARSAT, the satellite communication service provider has provided notice that all TerraStar L-Band frequencies will be migrated to the upper L-band (1545 MHz and higher) in early 2018. The L-Band frequency change is needed to minimize any potential impact from future Mobile Satellite Services (MSS) that will share the lower portion of the current L-Band spectrum (1526-1536 MHz).

4. What services will be affected by the L-Band frequency change?

All TerraStar services transmitted via satellite; including TerraStar-C, TerraStar-L and RTK ASSIST as well as Oceanix services will be impacted by this change.

5. Who will be affected by the L-Band frequency change?

All current and future TerraStar and Oceanix correction service users operating OEM6 and OEM7 receivers.

6. Is there a need for a firmware update?

NovAtel receivers with non-compatible firmware will not track the L-Band signal at the new frequencies. Even if the user has manually configured the receiver to track a new frequency, or requested the receiver to automatically find the new frequency, the new frequency will not be tracked persistently resulting in loss of precise positioning.

NovAtel receivers must be updated to compatible firmware versions before the frequency change, to ensure continuous operation of TerraStar services during and after the transition.

Receivers with compatible firmware versions will operate without any issues during and after the frequency change.  

7. What firmware versions are compatible?

Please refer to the table below for information on compatible firmware versions:

Receivers NovAtel Product Compatible Firmware
OEM6 Receiver Board: OEM628
Enclosures: FlexPak6, FlexPak6D
SMART Antennas: SMART6-L
6.710 or later
OEM6 Receiver Board: OEM638
Enclosures: ProPak6
6.606
OEM6 SPAN® Enclosures 6.631 or later
OEM7 All products 7.200 (7.02.00) or later

 

8. How can I ensure my receiver work without any issue during the L-Band frequency change?

  • Confirm the receiver is loaded with the compatible firmware version, prior to the L-Band frequency change (March 2018)
  • Turn on the receiver and track the specific L-Band beam for few hours during the frequency change period (see L-Band Frequency Change Schedule), or
  • Manually assign the new L-Band frequency after the turn on date for a specific beam and save the configuration (see SAVECONFIG command)

9. How does the L-Band frequency get updated in the receiver?

During the entire frequency change period, the new L-Band beam table is broadcast on both the old and the new frequencies every few hours. If the receiver is powered on and tracking, it will pick up the new L-Band beam table containing the new frequencies. Once the beam table has been updated in the receiver, the L-band signal tracking uses the new frequencies from that point forward.

During the frequency change period, the receiver is designed to seamlessly receive and update the L-Band beam table and switch to the new frequency without the need for manual intervention. Please ensure that the receiver is powered on and tracking for several hours during the transition period. 

10. How can I verify the L-Band frequency change in the receiver? 

Users can verify the L-Band frequency change by checking the LBANDBEAMTABLE log. With Stage 1 transition, the frequencies for beams 98W, AORE and 143.5E should be updated to the new frequency. With Stage 2 transition, the frequencies for all the beams should be updated to the new frequency.

Abbreviated ASCII Examples:

After Stage 1 (Beams 98W, AORE and 143.5E should have the new frequencies)

<LBANDBEAMTABLE COM1 0 74.5 UNKNOWN 0 0.151 02440000 f3b2 45228
<     7
<          "AORE" "A" 1545855000 1200 -15.50 1
<          "AORW" "B" 1539892500 1200 -54.00 1
<          "IOR" "C" 1539902500 1200 64.50 1
<          "POR" "D" 1539942500 1200 178.00 1
<          "25E" "E" 1539882500 1200 25.00 1
<          "143.5E" "F" 1545835000 1200 143.50 1
<          "98W" "G" 1545865000 1200 -98.00 1

After Stage-2 (All TerraStar beams should have the new frequencies)

<LBANDBEAMTABLE COM1 0 74.5 UNKNOWN 0 0.151 02440000 f3b2 45228
<     7
<          "AORE" "A" 1545855000 1200 -15.50 1
<          "AORW" "B" 1545845000 1200 -54.00 1
<          "IOR" "C" 1545865000  1200 64.50 1
<          "POR" "D" 1545905000  1200 178.00 1
<          "25E" "E" 1545825000  1200 25.00 1
<          "143.5E" "F" 1545835000 1200 143.50 1
<          "98W" "G" 1545865000 1200 -98.00 1

11. What happens if the receiver was never turned on during the frequency change period? 

If the receiver was never turned on or did not track long enough to get the new L-Band beam table, the receiver will most likely have the old frequencies. This can be verified by checking the LBANDBEAMTABLE log.

After Stage 1, the receiver will not track Stage 1 beams (98W, AORE, and 143.5E) but can track any visible Stage 2 beams (POR, AORW, 25E and IOR). After a few hours of L-Band tracking, the receiver will get the new L-Band beam table, which should allow it to track the Stage 1 beams on the new frequency.

After Stage 2, the receiver will not track any beams and will require a manual update of the frequency. Once the receiver is updated with the new L-Band beam table, it will be able to track any of the new frequencies (for visible beams).

Users can manually assign the beam to a new frequency any time after the turn ondate of the specific beam, to get the correction signal and update the L-Band beam table. 

12. My receiver is still tracking the beam on the old frequency, why? 

During the frequency change period, the receiver will continue to track a beam on the old frequency until it has received and updated the beam table. This may take several hours of continuous L-Band tracking. If a specific beam is manually assigned to the old frequency (and saved to configuration), the beam will continue to track on old frequency until the turn off date.

Checking the LBANDBEAMTABLE and LBANDTRACKSTAT will confirm the beam frequency being tracked by the receiver.

Receivers tracking any Stage 1 beams (98W, AORE and 143.5E) should switch automatically to new frequencies after a few hours of continuous L-Band tracking. Stage 2 beams will continue to be tracked on old frequencies until Stage 2 begins (after Aug 15, 2018). After Stage 2 begins, the receiver should only be tracking a beam on the new frequency.

13. I don't have an active subscription; can the receiver track the new L-Band frequency? 

An active TerraStar subscription is not required to track the L-Band signal. A receiver with L-Band capable model is sufficient. To support the L-Band frequency change, the receiver must also have a compatible firmware version. The receiver must be turned on and tracking the L-Band beam on either the old or new frequency for several hours during the transition period.  After the transition period (May 15, 2018 for Stage-1 and October 15, 2018 for Stage-2), receivers that are not updated, should be manually assigned with the new L-Band frequency. The receiver must track the beam for several hours to update the stored L-Band beam table.

Example: ASSIGNLBANDBEAM MANUAL 98W 1545865000 1200

14. Where can I get more information or assistance? 

For assistance and further information, it is strongly recommended to contact your local NovAtel dealer or sales representative, or NovAtel customer support.