O&M 

Operation And Maintenance

OAM 

Operations Administration and Maintenance

OCCCH 

ODMA Common Control Channel

OCH 

Optical Channel

OCN 

Original Called Network

OCR 

Optical Character Recognition

ODCH 

ODMA Dedicated Channel

ODMA 

Opportunity Driven Multiple Access

ODTCH 

ODMA Dedicated Traffic Channel

OFDM 

Orthogonal Frequency Division Multiplexing

OIF 

Orange Integration Framework

OL 

Optical Link

OLAF 

Orange Look And feel

OLAP 

OnLine Analytical Processing

OLT 

Optical Line Termination

OLTP 

On-Line Transaction Processing

OMC 

Operations and Maintenance Center

OMC-G 

Operations and Maintenance Center for GPRS

OMG 

Object Management Group

OMS 

Optical Multiplex Section

OMU 

Operation and Maintenance Unit

ONP 

Open Network Provision

ONU 

Optical Network Unit

OoBTC 

Out of Band Transcoder Control

OOM 

Object-Oriented Middleware

OPEX 

Operational Expenditures

ORACH 

ODMA Random Access Channel

ORB 

Obejct Request Broker

OS 

Operatice System

OSA 

Open Service Architecture

OSI 

Open System Interconnection

OSP 

OrangeWorld Service Platform

OSPF 

Open Shortest Path First

OSS 

Operation Sub-System

OTA 

Over the Air Activation

OTS 

Optical Transmission Section

OTS 

Object Transaction Service

OUI 

Organisationally Unique Identifier

OVSF 

Orthogonal Variable Spreading Factor