User's Manual

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Chapter 2 LTE eNB Overview
LTE eNB System Description v2.0 18
Copyright © 2017, All Rights Reserved.
However, if different UEs in neighbor cells use the same resource, interference
may occur. This occurs more seriously between UEs located on the cell edge,
resulting in serious degradation at cell edge.
A scheme used to relieve such inter-cell interference problem on the cell edge is
ICIC.
The ICIC allows interference signals to be transmitted to other cells in the cell
edge area in as small an amount as possible by allocating a basically different
resource to each UE that belongs to a different cell and by carrying out power
control according to UE’s location in the cell.
The eNBs exchange scheduling information with each another via X2 interface for
preventing interferences by resource conflicts at cell edges. If the interference of a
neighbor cell is too strong, the system informs other system to control strength of
the interference system.
The ICIC scheme is used to improve the overall cell performance.
MIMO
The LTE eNB supports 2Tx/2Rx, 2Tx/4Rx or 4Tx/4Rx MIMO by default using
multiple antennas.
To support multiple antennas, the baseband module of the eNB channel card
processes MIMO, and each path of the RF is processed separately. The LTE eNB
provides high-performance data services by supporting several types of MIMO.
Call Processing Function
Cell Information Transmission
In a serving cell, eNB periodically transmits a Master Information Block (MIB)
and System Information Blocks (SIBs), which are system information, to allow UE
that receives them to perform proper call processing.
Call Control and Air Resource Assignment
The eNB allows UE to be connected to or disconnected from the network.
When UE is connected to or released from the network, eNB transmits and
receives the signaling messages required for call processing to and from UE via
the Uu interface, and to and from EPC via the S1 interface.
When UE connects to the network, eNB performs call control and resource
allocation required for service. When UE is disconnected from the network, eNB
collects and releases the allocated resources.
In case of more information on the handover procedure, refer to ‘Message Flow’
section below.