Section: 6.1.3.6 Power Headroom Report MAC Control Element
Content: The Power Headroom Report (PHR) MAC control element is identified by a MAC PDU subheader with LCID as specified in table 6.2.1-2. It has a fixed size and consists of a single octet defined as follows (figure 6.1.3.6-1): - R: reserved bit, set to "0"; - Power Headroom (PH): this field indicates the power headroom level. The length of the field is 6 bits. The reported PH and the corresponding power headroom levels are shown in Table 6.1.3.6-1 below (the corresponding measured values in dB can be found in clause 9.1.8.4 of TS 36.133[ Evolved Universal Terrestrial Radio Access (E-UTRA); Requirements for support of radio resource management ]  [9]). Figure 6.1.3.6-1: PHR MAC control element Table 6.1.3.6-1: Power Headroom levels for PHR