I have a question about using CBRS class B devices for Fixed Wireless Internet over LTE. I’m new to this.
I understand that SAS registration allows transmitting at high power. But the device as initially installed will be on low power (class A level) and it must first connect to the network before a registration and grant can be obtained. Thus the radio installation must be within transmission range of the tower to connect at low power. Also there will be times when the SAS forces a GAA device to go down to low power, so it has to be installed in range anyway.
So it seems that SAS registration does not increase the effective service area as the radio must be functional at low power. I’m told that at cell edge the higher transmit power may increase the available upload bandwidth. Is that true and is that the only benefit for Internet use? Would there be any benefit to registering service locations that are nearer the tower? Assume GAA priority only.
This really depends on the type of equipment you’re planning to use. There is a distinction in how the radios connect to the network. In the case of PMP 450 from Cambium Networks, our Subscriber Modules (SMs or CPE) are CBSD Category B devices (i.e. High power).
CBSD-CPE rules allow pilot tones and beacons to be sent at high power to allow the radio to establish connectivity to the Access Point (AP or sector). While it is possible that, when another radio system requests a grant, and the spectrum is being fully utilized, the SAS may require existing radios to adjust their power levels, this is not commonly observed, and can be mitigated in several ways.
As with any wireless system, operating at the highest possible modulation levels will allow the fastest data transmission rates. This is more easily done nearer to the AP, so SM radios located closer to the AP have a better chance of this. With the PMP 450 system, Uplink and Downlink are completely configurable in terms of frame timing, from 85% up to 85% downlink in 1% increments. Typically, for residential broadband, operators set this to 70% downlink or more.
If I haven’t answered your question, I invite you to please continue the conversation in this thread…
BEC Ridgewave 6900-R21.
This is a class B device. As far as I know the radio can’t transmit at high power without a grant from the SAS. And to get that it has to be connected first at low power. Chicken and egg. In a scenario where the radio would be in cell range at high power but not at low power, it can’t connect to get a grant.
As stated above, CBSD-CPE rules allow pilot tones and beacons to be sent at high power to allow the radio to establish connectivity to the Access Point (AP or sector). This is how it is done with PMP 450 equipment, and how the equipment was issued its grant from the FCC.