8.2.1 Introduction to the TMN
1. Basic Concepts of the TMN
TMN is the abbreviation of Telecommunication Manager Network. The TMN supports the management of telecommunication networks and services by transmitting/storing/processing information.
The TMN can manage various types of telecommunication networks and the network elements such as analog/digital network, the public network/private network, the switching system/transmission system, the telecommunication software, the network logic resources (like the circuit/route/service) and auxiliary supporting systems (like the power system and the air-conditioning system).
The TMN is the telecommunication network management standard presented by ITU-T. As a part of the telecommunication supporting network, TMN is separate from the telecommunication service in principle.
2. Basic Model and Features of the TMN
1) Introduction to the TMN architecture
The TMN consists of multiple layers with each layer corresponding to a different management mode.
NEF: Network Element Function
EML: Element Manager Layer
NML: Network Manager Layer
SML: Service Manager Layer
BML: Business Manager Layer
According to the figure above, the TMN consists of different management layers, interconnected via an interface. The TMN is a bottom-up network system with products as the core. The layers are described as follows:
l Business Management Layer
Providing support for service-oriented decision functions, such as report statistics and performance trend analysis.
l Service Management Layer
Providing the customer-oriented management functions to manage the services offered to the customer and to collect the accounting information and the feedback information of the network service quality.
l Network Management Layer
Providing network-oriented operation and management, such as network traffic monitoring and fault monitoring.
l Network Element Management Layer
Delivering equipment-oriented operation and maintenance.
l Network Element Function
As the basis of the TMN O&M system, the
OM system at the NE side provides NE operation
and maintenance, and upper interfaces with the TMN.
2) Features of the TMN Architecture
l Built from bottom up with products as the core;
l Based on interoperation between devices with the ultimate objective of unified management over the equipment of different vendors;
l Defines corresponding interface and information model;
l Focuses on the NEF-EML-NML relationship, giving priority to OMS (operation & maintenance system) support in terms of service, while the SML and the BML in the model are not addressed.
8.2.2 Introduction to the TOM Model
In 3GPP, the description of the NMS is based on the TMN model of ITU-T as well as ideas of the TOM model presented by TMF. Especially in versions higher than 3GPP (R5), it comes even closer to the TOM model. The following is about the model.
TOM (Telecom Operations Map) is a new generation of the NMS model put forward by the TMF (Telecommunication Management Forum), which is a non-profitable organization committed to providing leading, strategic and practical solutions to improve the communication service management and operation quality. In addition, it develops the programmed market-based solutions to address the major problems arising in connection with
integration and business procedure automation. It has 384 members from large
companies, organizations and associations, including service providers,
software solution suppliers, computer/network equipment suppliers and customers
using communication services. OSS
Simply speaking, the TOM involves such vertical processes as service implementation, service assurance and service billing as well as one cross-carrier process. Horizontally, it also includes such layers as care, service development & operation, and network development & operation. The customer care layer includes five parts: sales, order processing, troubleshooting, customer QoS management and bill payment (i.e. billing). The layer for service development and operation also comprises five parts: service planning and development, service configuration, service problem management, service QoS management and rating/discounting. The layer for network development and operation consists of another five parts: network planning and development, network provisioning, network inventory management, network maintenance & restoration and network data management.
In the WCDMA NMS, the O&M layer relies heavily on the building of the TMN O&M network system (NMF-EMS-NMS), while the accounting management, the business forecast and the network service provision are based on the TOM model.
8.2.3 Introduction to the WCDMA NMS
1. Goals of the WCDMA NMS
l To manage the equipment of different vendors, including the management system itself;
l To simplify the UMTS network management;
l To support the communication between the UMTS NE and the UMTS OS or between the UMTS OSs via the standard interfaces;
l To reduce the cost of the UMTS network management;
l To provide the capability of flexible and fast service configuration;
l To provide comprehensive fault management capability;
l To simplify the operation and maintenance with local or remote O&M functions;
l To allow for the exchange of the network management and the accounting information between the network manager and the service provider, and the exchange of information with different networks, including other UMTS networks and non-UMTS networks;
l To support and control the growth of resources, and with scalability, to satisfy the requirements of smooth expansion according to the development of network services;
l To provide a security management mechanism based on the whole UMTS NMS;
l To provide flexible billing and accounting management, and to support the account settlement between the UMTS and the non-UMTS networks;
l To provide transaction notification; for example, the change in the property of an NE may cause some changes to this NE or other NEs. These changes are one-time changes and should be reported as events;
l To provide the capability of restoring the UMTS system.
2. Introduction to the
With a good operation support system, the operator can fully understand the operation status of the network equipment and the network service quality, and deploy the services efficiently, thus improving its operation and maintenance efficiency and service quality as well as the competitiveness.
Based on the TMN and TOM architectures, the WCDMA NMS provides relevant NMS frameworks.
The basic framework of the NMS described in 3GPP is shown as the figure below. The UMTS Operation System in the figure also adopts a hierarchical structure (LA, logic layer architecture), which may be considered an equivalent to the equipment system at the EML/NML layer of the TMN framework. The
systems is the information system used in the communications system, which has
no direct or substantial connection with communication services. It includes
the call center, the fraud detection and prevention system and the billing
Interface 1: The interface between the NE and the OS. Generally, it means the interface between the NE and the EML. If the NE itself provides a network management interface, it also refers to the interface between the EML and the NML.
Interface 2: The interface between the OS and the
system. It may be considered as the interface between the OS layer and the
service provisioning system, similar to the interface between the NML layer and
the upper layers in TMN. Enterprise
Interface 3: It means the interface between
. It may be
the OS interface between the UMTS networks, or the interface between a UMTS
network and a non-UMTS network, such as the PSTN or other networks; OSs
Interface 4: It indicates the interface among the layers of an OS, similar to the interface between the EML and the NML.
According to the figure above, the
3G NMS is designed to provide a complete,
open and scalable operation support system to support the UMTS network and
3. Comparisons between the
3G NMS and the 2G NMS
The NM functions of a traditional
2G mobile network are based on the TMN
network management framework, and focused on the service functions of the
equipment O&M layers. In the main, it provides management functions in five
areas as defined by ITU:
l Performance Management
l Fault Management
l Configuration Management
l Accounting Management
l Security Management
As a network management product, it must provide centralized operation and maintenance based on the network-wide equipment, so the NMS generally needs to provide such functions as centralized topology management and centralized operation & maintenance. These are the basic functions of the OMS of the
According to the management objectives of the
3G NMS above, there is no
substantial difference between the 3G
NMS and the 2G NMS. In
terms of architecture and service functions, the 3G NMS adheres to the characteristics of the 2G NMS. However, the WCDMA network is more
complex than the 2G network.
Below are some differences between the 2G NMS and the 3G NMS.
1) The architecture of the
NMS is more reasonable than that of the 2G NMS
2G NMS is designed based on the idea of TMN network
management, so the operation and maintenance layer (O&M layer) is fairly
perfect. However, it is deficient in the entire operation layer ( layer), where
services are not well integrated. OSS
3G NMS is intended to deliver an integrated operation
network based on numerous management theories such as TMN and TOM, combining
the features such as network maintenance, management, service deployment and
operation, to develop an integrated support system solution.
2) More openness between networks
2G NMS, the standards of the interfaces between the NE
and the EMS, between the EMS
and the NMS, and among different networks vary largely, making it difficult to
develop an integrated O&M network system. As a result, it is difficult for
operators to keep fully informed about the NMS operation status and deploy
services quickly by establishing an unified O&M network system given
multiple equipment vendors, different standards and complex structures.
3G NMS pays more attention to interface
standardization and normalization, guiding the standardization of the
interfaces between the NE and the EMS, or
between the EMS and the NMS, and between the
O&M layer and the
layer, to develop an integrated O&M solution. OSS
In addition, the sharing of information among UMTS networks, or between a UMTS network and a non-UMTS network is also addressed in the
3G NMS. All
this relies on interface standardization.
3) Wide application and recommendation of the CORBA technology
3G NMS construction, it is strongly recommended to
adopt a CORBA technology-based architecture with an object-based description of
the network structure, to shape a unified O&M idea. It is also recommended
to take the CORBA interface standard as the standard for NMS interface on the
layers of the O&M network system for the normalization of the interfaces.
In addition, the CORBA technology brings a distributed network structure in real sense, making it easier for future network expansion and service development.
4) More perfect service features
In addition to the
2G NMS feature, the 3G NMS provides more service features such as
network-wide software management, OoS management and location management. The
details will be described in the introduction below.
3G NMS serves
to manage a diversity of service areas through different layers
Overall management over the operation of
3G services calls for a large amount of
complicated systems engineering. Its features include:
l Multiple managed network layers, each of which has a variety of devices, and these devices may be provided by different vendors;
l The business mode of the
service is much more complicated than that of the traditional voice service,
involving varied services and service providers and multi-vendors;
l The network structure and the equipment type varies with the network system, and even the same kind equipment in different systems calls for different services;
l Different vendors use different technologies on their equipment, for example, some vendors adopt the ATM technology, while some adopt the IP technology;
l The wireless service itself has some complex features, such as cell management, roaming management and mobility management. All these features make the
3G service management
l Each network equipment layer of the
3G service environment comprises five parts: access
equipment (i.e. mobile phone/terminal), wireless access network, core network,
service release network and content & service. To fully support the 3G service operation, we need to manage these
3G NMS manages various service areas through different
In addition, mobile network management must attain the objectives of greater customer satisfaction but lower cost:
l - Providing highly-personalized communication service
l - The growth of individual subscribers exceeding that of enterprise subscribers
l - Segregating the roles of service provider and network operators between the home environment and the service network entity.