System Description

Confidential
Chapter 2 SOL230 Overview
SOL230 System Description v1.0 14
Copyright © 2017, All Rights Reserved.
dividing it into units of RLC PDU at the transmitting side and the packet is
retransmitted (forwarded) according to the ARQ feedback information received
from the receiving side for increased reliability of the data communication.
QoS Support
The SmallCell receives the QoS Class Identifier (QCI) in which the QoS
characteristics of the bearer are defined and the GBR, the MBR, and the
Aggregated Maximum Bit Rate (UE-AMBR) from the EPC. It provides the QoS
for the wireless section between the UE and the SmallCell and the backhaul
section between the SmallCell and the S-GW.
Via the air interface, the SmallCell performs retransmission to satisfy the rate
control according to the GBR/MBR/UE-AMBR values, priority of bearer defined
in the QCI, and scheduling considering packet delay budget, and the Packet Loss
Error Rate (PLER).
Via the backhaul interface, the SmallCell performs QCI-based packet
classification, QCI to Differentiated Services Code Point (DSCP) mapping, and
marking for the QoS. It provides queuing depending on mapping results, and each
queue transmits packets to the EPC according to a strict priority, and so on.
In the Element Management System (EMS), in addition to the QCI predefined in
the specifications, operator-specific QCI and QCI-to-DSCP mapping can be set.
IP Processing
IP QoS
The SmallCell can provide the backhaul QoS when communicating with the EPC
by supporting Differentiated Services (DiffServ).
The SmallCell supports eight DiffServ classes and mapping between the services
classes of the user traffic received from the UE and DiffServ service classes. In
addition, the SmallCell supports mapping between the Differentiated Services
Code Points (DSCP) and the 802.3 Ethernet MAC service classes.
IP Routing
Because the SmallCell provides multiple Ethernet interfaces, it stores the
information on which Ethernet interface the IP packets will be routed to in the
routing table. The routing table of the SmallCell is configured by the operator. The
method for configuring the routing table is similar to the standard router
configuration method.
The SmallCell supports static routing setup. However, but it does not support
dynamic routing protocols, such as Open Shortest Path First (OSPF)/Border
Gateway Protocol (BGP).
SON Function
The SON function supports the self-configuration, self-establishment and self-
CONFIDENTIAL