The GNSS module is present on the front panel of the RSP3 module and can be ordered separately with PID=. However, there is no license required to enable the GNSS module.

The GNSS LED on the RSP3 front panel indicates the status of the module. The following table explains the different LED status.

When connected to an external antenna, the module can acquire satellite signals and track up to 32 GNSS satellites, and compute location, speed, heading, and time. GNSS provides an accurate one pulse-per-second (PPS), a stable 10 MHz frequency output to synchronize broadband wireless, aggregation and pre-aggregation routers, and an accurate time-of-day (ToD).

Note	The RSP3 module can also receive 1PPS, 10 MHz, and ToD signals from an external clocking and timing source. However, the timing signals from the GNSS module (when enabled) take precedence over those of the external source.

By default, anti-jamming is enabled on the GNSS module.

The GNSS module has the following stages of acquiring and providing timing signals to the Cisco router:

• Self-Survey Mode—When the router is reset, the GNSS module comes up in self-survey mode. It tries to lock on to minimum four different satellites and computes approximately 2000 different positions of the satellites to obtain a 3-D location (Latitude, Longitude, and Height) of it current position. This operation takes about 35-to-40 minutes. During this stage also, the module is able to generate accurate timing signals and achieve a Normal or Phase-locked state.

When GNSS moves into Normal state, you can start using the 1PPS, 10 MHz, and ToD inputs from GNSS. The quality of the signal in Self-Survey mode with Normal state is considered good enough to lock to GNSS.

• Over determined clock mode—The router switches to over determined (OD) mode when the self-survey mode is complete and the position information is stored in non-volatile memory on the router. In this mode, the module only processes the timing information based on satellite positions captured in self-survey mode.

The router saves the tracking data, which is retained even when the router is reloaded. If you want to change the tracking data, use the no shutdown command to set the GNSS interface to its default value.

The GNSS module stays in the OD mode unless one of the following conditions occur:

• A position relocation of the antenna of more than 100 meters is detected. This detection causes an automatic restart of the self-survey mode.

• A manual restart of the self-survey mode or when the stored reference position is deleted.

• A worst-case recovery option after a jamming-detection condition that cannot be resolved with other methods.

You can configure the GNSS module to automatically track any satellite or configure it to explicitly use a specific constellation. However, the module uses configured satellites only in the OD mode.

Note	GLONASS and BeiDou satellites cannot be enabled simultaneously. GALILEO is not supported.

When the router is reloaded, it always comes up in the OD mode unless:

• the router is reloaded when the Self-Survey mode is in progress

• the physical location of the router is changed to more than 100 m from it’s pre-reloaded condition.

When the GNSS self-survey is restarted using the default gnss slot R0/R1 command in config mode, the 10MHz, 1PPS, and ToD signals are not changed and remain up.

The Cisco ASR 903 and Cisco ASR 907 routers have two GNSS modules, one each on the active and standby RSP3 modules. Each GNSS module must have a separate connection to the antenna in case of an RSP3 switchover.

GNSS firmware is integrated into the Cisco IOS XE Everest 16.5.1 image. When you load this image, the GNSS firmware is copied to the /usr/binos/bin/ directory.

If the version of the firmware in the software image is greater than the current running verison, firmware is automatically upgraded.

You cannot obtain the GNSS data from the standby RSP device for Cisco ASR900 RSP3 Module HA system.

enable
configure terminal
gnss slot r0
no shutdown
exit

Note	After the GNSS module is enabled, GNSS will be the source for 1PPS, ToD, and 10MHz clocking functions.

enable
configure terminal
gnss slot r0
constellation [auto | gps | galelio | beidou | qzss
exit

enable
configure terminal
gnss slot r0
1pps polarity negative
exit

Note	The no 1pps polarity negative command returns the GNSS to default mode (positive is the default value).

enable
configure terminal
gnss slot r0
1pps offset 5
exit

Note	It is recommended to compensate 5 nanosecond per meter of the cable.

The no 1pps offset command sets cable delay offset to zero.

enable
configure terminal
gnss slot
 
ro
anti-jam disable
exit

Use the show gnss status command to display status of GNSS.

Router# show gnss status
GNSS status:
 
  GNSS device: detected
  Lock status: Normal
  Receiver Status: Auto
  Clock Progress: Phase Locking
  Survey progress: 100
  Satellite count: 22
  Holdover Duration: 0
  PDOP: 1.04   TDOP: 1.00
  HDOP: 0.73   VDOP: 0.74
  Minor Alarm: NONE
  Major Alarm: None

Use the show gnss satellite command to display the status of all satellite vehicles that are tracked by the GNSS module.

Router# show gnss satellite all
All Satellites Info:
 
SV PRN No   Channel No       Acq Flg    Ephemeris Flg     SV Type     Sig Strength
----------------------------------------------------------------------------------
14          0                      1                1           0               47
21          2                      1                1           0               47
22          3                      1                1           0               46
18          4                      1                1           0               47
27          6                      1                1           0               44
31          8                      1                1           0               49
24          10                     1                1           0               42
79          12                     0                1           1               18
78          13                     1                1           1               26
 
Router# show gnss satellite 21
Selected Satellite Info:
 
  SV PRN No: 21
  Channel No: 2
  Acquisition Flag: 1
 Ephemeris Flag: 1
  SV Type: 0
  Signal Strength: 47
 

Use the show gnss time and show gnss location to display the time and location of the Cisco ASR 902 or Cisco ASR907 router.

Router# show gnss time
 
Current GNSS Time:
 
  Time: 2015/10/14  12:31:01 UTC Offset: 17
 
Router# show gnss location
Current GNSS Location:
 
  LOC: 12:56.184000 N  77:41.768000 E 814.20 m

Use the show gnss device to displays the hardware information of the active GNSS module.

Router# show gnss device 
GNSS device:

  Serial number: FOC2130ND5X
  Firmware version: 1.4
  Firmware update progress: NA
  Authentication: Passed

The following example shows the configuration example of telemetry for GNSS module:

configure terminal
telemetry ietf subscription 1
encoding encode-tdl
filter tdl-uri /services;serviceName=ios_emul_oper/gnss_data
source-vrf Mgmt-intf
stream native
update-policy periodic 1000
receiver ip address 7.0.1.112 45000 protocol native