docker build -f docker/Dockerfile.gnb_e2 -t nakaolab:sep1 .

O-RU and O-DU are connected via the Fronthaul (FH) interface.
FH traffic is logically diviced into 4 planes:
1. Control Plane which transports real-time slot configuration control messages
2. User Plane which transports IQ samples data (amplitude and phase)
3. Synchronization Plane transports timing information messages
4. Management Plane carries non-real-time management operation messages

C/U Plane messages are exchanged using the eCPRI protocol.

The energy consumption of RU can be modeled as
P = P_0 + P_RF + P_BB + P_PAM
where
P_0   : baseline components in the RU (fabric, ethernet, PCIe, etc.)
P_RF  : a-to-d/d-to-a converters (ADC/DAC) and the freq up/down converters
P_BB  : core digital processor (eFPGA) and the other low-PHY processing units
        (e.g. beamforming) for each antenna chain
P_PAM : power amplifier module (PAM) at each antenna chain

The paper claims that components other than PAM are rather static (?)
-> I guess the PAM is controlled by RF. Thus P_RF is the minimum amount of power
   required to run RF.

P_PAM = P_(PAM, 0) * P_(PAM, c)(r) * E_PAM * n_ant
where
P_(PAM, 0) : baseline power consumption that depends on the n of antennas,
             ganging elements, and the maximum EIRP per antenna
             * EIRP (Effective Isotropic Radiated Power) is the total power radiated
             by an antenna in the direction of its maximum gain, referenced to an ideal isotropic radiator.
P_(PAM, c)(r) : a factor that depends on _the amount of subcarriers to be amplified_,
                which in turn depends on the n of RBs (r) carried therein
E_PAM         : captures the efficiency of the amplifier to convert DC power into signal power gain
n_ant         : n of radio chains (with ONE amplifier per radio chain)

> This observation motivates the principle behind the solution we propose in this paper:
  consolidate data into as few symbol periods as possible, using more radio resources per period instead.
Since keeping PAM awake consumes more energy, it is better to send data in short bursts, where each burst
utilizes more spectrum resources



MIMO Muting