LTE CA primary band lock


#1

In BR1 ENT, is there a way to lock which band is the primary in carrier aggregation? I’m currently using another brand and the router usually selects band 20 to be the primary band and uses that for uploads, even though band 3 has more upload bandwidth. I’d like to be able to lock it to band 3 or at least influence the selection process to steer it towards the better band.


#2

Hello pmaa,

I don’t think that we support Band prioritization at this time but you can manually select the bands.

You can limit to specific bands. Band Selection can be found in the Cellular Settings. If you click the question mark next to LTE/3G a help box will open with the option to ‘click here’ to enable advanced band selection. Once you’ve done that a Band Selection option will be added to the Cellular Settings.


#3

Could you share how the unit selects a band? E.g., at one location we have bands 4 and 13 available, and the radio sometimes picks 4 (low quality signal), and sometimes 13 (much better quality). We would prefer it to pick whatever band provides the better signal without having to lock it in manually.
The unit is a Balance 30 LTE on Verizon.


#4

The tower will tell the device what band to use and I’m sure they look at strength, quality, S/N, distance, and probably band saturation as well.


#5

Thanks. I guess our towers have other priorities than the quality of the particular connection (we gain some 10dBm (give or take a few) over Band 4 whenever we lock the connection to Band 13).


#6

How do the RSRP, RSRQ, and S/N compare between the two?


#7

As of this moment:
Band 13: RSSI: -63dBm SINR: 3dB RSRP: -95dBm
Band 4: RSSI: -74dBm SINR: -2dB RSRP: -108dBm

The location is marginal and the antennas stock, so this is not a great location for the device - however, it made me really notice the band issue.

We had similar experiences with an HD2 IP67 LTE-A: Sometimes B13 would be primary, sometimes B4. The connection was always better whenever B13 would be primary.
Which Band was set as primary seemed arbitrary - cycling the modem connection on/off would yield different band choices - sometimes B4, sometimes B13


#8

I had exactly the same problem. Sometimes the primary band would change after rebooting to the better band, but generally it would lean towards the other band with poorer upload bandwidth. I’ve since changed providers to a one that is more stable.

I’m not sure if there is a configuration issue with the provider not offering the better primary band, or if there’s a gap between current software implementations and the CA standard, but for this type of case it would be beneficial to have an option to lock the primary band.


#9

A followup with data on a HD2 IP67 HW3 on Verizon, LTE-A:
(at least) three bands available, B13, B4, B2.
Left to itself, the HD2 picks B2+B13 and B4+B13 (B13 being the secondary)
Speeds are so-so (5 Mbps at best).
When locking to B13 with no secondaries, the speeds double/triple - 10-15 Mbps at best.
This raises two issues:

  1. B13 is undeniably superior, yet is not chosen as a primary band
  2. Furthermore, the only way to reliably get B13 as the primary is to deny a secondary band altogether, i.e. LTE instead of LTE-A.
    Mind you, this is based on a few samples in a single location on a particular day, but the degree of arbitrariness troubles me (whether it be caused by Verizon or by the modem implementations).

On the plus side: This particular unit will be deployed in the mountains, where LTE-A has yet to be deployed :slight_smile: