How to distribute RRU power between LTE cells with different bandwidth?
For example, I need to to split 46 dBm for 3 LTE carriers, with different bandwidth: 5 MHz, 10 MHz and 20 MHz.
the 1st carrier (20Mhz) has a RSpower of 15.2dBm, which uses a power of 20W/port
the 2nd carrier (10 Mhz) has a RS power of 15.2dBm, which uses a power of 10W/port
the 3rd carrier (5 Mhz) has a RS power of 15.2dBm, which uses a power of 5 W/port
Total power=35 Watts not exceed the ability of the RRU. (40 Watts)
I believe it depends on the design of each network.
What is there is documentation with typical power configurations for the RRU model.
If it fits in the RRU specification, you can divide as it is more convenient.
Considering an equivalent coverage (assuming frequencies close to each other), the power distribution would be proportional to the bandwidth.
But the engineer may want to prioritize the 20 MHz layer leaving its coverage a little larger than the others, to absorb more traffic.
That’s my undesrtanding.
It depend on Which Carrier Frequency you want to set as Capacity Layer/Coverage Layer. In general If frequencies are close to each other than RS Power is set Equal for all the carriers.
Now assuming single Port antenna … 46 dbm=40 Watt RRH Power can be distributed as per the below Setting.
There will be a little variance with respect to setting proposed above and Actual Setting as per the setting of Pa/Pb Value for Individual carrier.
Firstly you should check harrdware capability of RRU, does it support 3 LTE carriers?
Cellular Internet of things
Authors: Olof Liberg, Mårten Sundberg, Johan Bergman (Ericsson Business Unit Networks), Y.-P. Eric Wang, Joachim Sachs, Gustav Wikström (Ericsson Research).
I would like to suggest you take a look at this book.
It will be helpful to arrive at the best answer, moreover discovering that its not an straight math calc, as soon as LTE and IOT will be sharing tasks and physical space.