Content for TR 22.897 Word version: 13.0.0
0 Introduction Word‑p. 5
In mission critical networks ensuring the ability of Public Safety officers to communicate is of the utmost importance. Isolated E-UTRAN Operation seeks to enhance the ability of Public Safety officers to communicate by investigating improved support for situations where users move out of E-UTRAN coverage or following the loss of backhaul communications.
1 Scope Word‑p. 6
The present document studies use cases and identifies potential requirements for Isolated E-UTRAN Operation in support of mission critical network operation for Public Safety.
2 References
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
- References are either specific (identified by date of publication, edition number, version number, etc.) or non specific.
- For a specific reference, subsequent revisions do not apply.
- For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of the present document, the terms and definitions given in TR 21.905 and the following apply.
A term defined in the present document takes precedence over the definition of the same term, if any, in TR 21.905.
Isolated E-UTRAN:
either an E-UTRAN without normal connectivity with the EPC or deployed NeNBs with E-UTRAN functionality.
Nomadic eNB (NeNB):
An NeNB is a nomadic cell and may consist: base station, antennas, microwave backhaul and support for local services. The NeNB is intended for Public Safety use providing coverage or additional capacity where: 1) coverage was never present (e.g. forest fire or underground rescue) or 2) where, for example, due to natural disaster coverage is no longer present.
Isolated E-UTRAN operation:
Comprises two situations: 1) In the event of an interruption to normal backhaul connectivity Isolated E-UTRAN operation aims to adapt to the failure and maintain an acceptable level of network operation in the Isolated E-UTRAN. The restoration of service is the eventual goal. 2) Operation following the deployment of one or more Nomadic eNBs either without backhaul or with limited backhaul.
Network redundancy:
In the event of failure redundancy aims to maintain network operation with minimum downtime. This is achieved with the addition, for example, of duplicate communication paths and network elements.
Network resiliency:
Resiliency is the ability of a system to operate under adverse conditions. Network Resiliency can draw on aspects of both network redundancy and Isolated E-UTRAN operation.
User:
Within the scope of the present document the use of the term 'user' is limited to Public Safety operation.
Limited backhaul capability:
Isolated E-UTRAN operation supports operation where the Isolated E-UTRAN has no backhaul capability to the EPC. Furthermore Isolated E-UTRAN operation may have limited backhaul capability to the EPC. For the case of limited backhaul capability to the EPC only the signalling of public safety Ues can reliably be communicated to the EPC; in addition users may have the possibility to transmit a limited amount of user data with no guarantee of service.
3.2 Symbols Word‑p. 7
For the purposes of the present document there are no specific symbols defined.
3.3 Abbreviations
