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Long Term Evolution (LTE) and LTE-Advanced Pro 287

RB set 1
RB set 2 + 1 + RB set 1 + 2
RB set 2

RB set 1 RB set 2
only only

Reduced interference as high power RBs
do not directly overlap here

Figure 4.27 Fractional frequency reuse for reducing cell‐edge interference.
those RBs for its own users. In addition, the Load Indication message on the X2 interface
can be used to inform neighboring eNode‐Bs regarding the RBs in which high interference
is experienced so that neighbors can change, limit or adapt the power usage of mobile
devices on certain RBs.
How eNode‐Bs use the information they receive from their neighbors is implementa-
tion specific and is not described in the 3GPP standards.

4.12.3 Self‐Organizing Network Functionality
In addition to interference management, there are a variety of other tasks that have to
be performed manually during the buildup of the network and afterward while main-
taining it to ensure high capacity and high availability. For LTE, 3GPP has created a
work item referred to as Self‐configuring and Self‐organizing Network (SON) to define
ways to optimize and automate many labor‐intensive tasks. 3GPP Technical
Recommendation (TR) 36.902 [24] gives an overview of a number of tasks that can be
fully or partially automated in the future:
Initial self‐configuration. Retrieval of basic operational parameters from a centralized
●
configuration server when the cell is first activated.
ANR. Mobile devices can report cells that are not in the neighbor list to the base
●
station they are currently served by. This information can then be used by the network
to automatically establish neighbor relationships for handovers.
Coverage and capacity optimization. Interference between cells due to extensively
●
overlapping coverage areas and coverage holes is one of the main issues for deployed
networks. Such conditions are usually detected with drive tests. Here, SON aims to
use mobile device and base station measurements to detect these issues. While inter-
ference can potentially be reduced automatically, unintended coverage holes can