4.7.7 Relay Node OAM Aspects

36.3003GPPEvolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN)Overall descriptionRelease 17Stage 2TS

4.7.7.1 Architecture

Each RN sends alarms and traffic counter information to its OAM system, from which it receives commands, configuration data and software downloads (e.g. for equipment software upgrades). This transport connection between each RN and its OAM, using IP, is provided by the DeNB; the reference architecture is shown in Figure 4.7.7.1-1. RN OAM traffic is transported over the Un interface, and it shares resources with the rest of the traffic, including UEs attached to the DeNB. The secure connection between the RN and its OAM may be direct or hop-by-hop, i.e. involving intermediate hops trusted by the operator for this purpose.

Figure 4.7.7.1-1: Relay OAM architecture.

It has to be noted that Figure 4.7.7.1-1 refers to normal operating conditions for the RN, i.e. after the initial start-up phase has been completed. The case where the secure connection between the RN and the OAM does not go through the DeNB, e.g. during the initial start-up phase, is not precluded.

4.7.7.2 OAM Traffic QoS Requirements

Alarms in the RN generate bursts of high-priority traffic, to be transported in real time. Traffic counters generate bursts of traffic, but their transport need not be real-time. Configuration messages from OAM to the RN will also generate small bursts of traffic, possibly with lower priority than alarms but still delay-sensitive: when a configuration is committed on the OAM, the time interval between the commitment and the effect on the equipment shall be small.

Alarm messages and commands should be transported on a high-priority bearer, while counters may be transported on a lower priority bearer. There is no need to specify a new QCI value other than those already standardized.

Alarm messages and commands may be mapped over a dedicated bearer or over the same bearer that carries S1 and/or X2 messages between the RN and the DeNB.

OAM software download to the RN may generate larger amounts of data, but both the required data rate and the priority of this kind of traffic are much lower than in the case of alarms, commands and counters. OAM software downloads may be mapped to a dedicated, non-GBR bearer, or transported together with the user plane traffic. If a dedicated bearer is used, it is FFS whether it shall be present at all times, or its setup should be event-triggered (software upgrades are triggered by the operator).

4.7.7.3 Security Aspects

Refer to clause D.2.5 of TS 33.401 [22] for details on secure management procedures for RN.

4.7.7.4 Void

4.7.7.5 OAM Requirements for Configuration Parameters

4.7.7.5.1 Parameters Associated with Relay Bearer Mapping

OAM provides the appropriate support to configure a QCI-to-DSCP mapping function at the relay node which is used to control the mapping in uplink of Uu bearer(s) of different QCI(s) to Un bearer(s).