9.1 WCDMA CS Domain Billing Principles


9.1.1  WCDMA CS Domain Billing Architecture


The billing system of WCDMA system CS domain is consistent with that of GSM system, that is, the billing data are both generated by MSC/MSC Server and directly transported to billing center. Therefore, in view of the architecture, the billing system of CS domain consists of billing module of MSC/MSC Server and billing center. Between the billing module and billing center, bill data are transported with FTP/FTAM file transporting protocol.
Because no specific interface parameter is prescribed for MSC/MSC Server billing module in the protocol, the interface between MSC/MSC Server host system and billing module is an internal interface, and the implementation of the billing module is also diversified. 

MSC/MSC Server billing system mainly consists of host modules and Bill Administration Unit (BAU). Figure 9-1 shows the CS domain billing architecture.
Host system: The bill information is generated from the host system, and firstly buffered in the bill pool of host. The original bills in the bill pool are, in the form of packet, continuously transported to BAU with TCP/IP.
Bill Administration Unit (BAU): BAU, the processing core of MSC/MSC Server billing system, is a dual-system hot backup system. Connected to the host through local area network (LAN) and to billing center through wide area network (WAN), BAU provides FTP/FTAM interface for billing center to support Server/Client in FTP and Responder in FTAM, to transport bills to billing center.
BAU functions: After saving the original bills received from the host system, it carries out sorting and format conversion for the original bills to generate the final bill. BAU saves the final bill and transports it to billing center. Specifically:
l   Saving original bills: After receiving the bill packets from the host, unpacking and validating the packets, BAU saves the received original bills in hard disk, then sends confirmation message to the host and makes the corresponding log record, and finally carries out sorting and format conversion for the original bills.
l   Sorting bills: It means classifying bills according to a domain, to process them in different flows and save them in different physical paths. All data domains in bills can be used as the criterion for sorting.
l   Bill format conversion: The format conversion on BAU involves choosing bill domain, changing the two-digit chronology into four-digit chronology, and converting into specified text format.
l   Saving final bill: After sorting and format conversion on the original bills, BAU saves the final bills in different directories according to their classification.
Billing center: Collecting and processing final CDRs, and generating final subscriber bills based on tariffs.

9.1.2  Billing Data Generated by MSC/MSC Server

1. Bill type

MSC/MSC Server can be used as VMSC, TMSC, GMSC and SSP. Different calls may have different bill types. The major bill types are as follows:
l   Mobile calling bill: A bill generated when a local mobile subscriber initiates a call.
l   Mobile called bill: A bill generated when a local mobile subscriber is called.
l   Roaming bill: A bill generated when a subscriber of another office calls a local subscriber.
l   Gateway office outgoing bill: A bill generated when a local subscriber calls a subscriber of another network.
l   Tandem bill: A bill generated when the caller and called are not local subscribers and this office is a TMSC.
l   Substituting bill: When a non-prepaid subscriber calls prepaid subscriber and it is an OVERLAY networking, SSP will replace the originating MSC to generate this bill to charge the non-prepaid calling subscriber.
l   Forwarding bill: A bill generated when a local subscriber is called and the call is forwarded.
l   Call attempt bill: A bill generated when a call is not successful.
l   SM bill: A bill generated when an SM is originated/terminated.
l   Special service bill: A bill generated when special service call or special service emergency call is involved.

2. Bill format

The bill format that MSC/MSC SERVER BAU provides for billing center complies with Mobile Phone Billing Standard Pre-processing Bill Format. BAU can provide billing center with bills in binary or text format as required.
A bill mainly consists of the following information:
l   WCDMA/GSM/PLMN resource utilization (such as MSC number and incoming/outgoing trunk group number)
l   Basic service utilization (in accordance with source, destination, call date, call time, call duration, and bearer service)
l   Supplementary services utilization (such as call forwarding)

l   Subscriber related numbers (such as MSISDN, IMSI and MSRN)

9. WCDMA Billing System


In a telecomm operating network, as subscribers are offered service, service billing is accompanied. Essentially, as a measure of the network resources used by subscribers, billing is classified into Circuit Switched (CS) domain billing and Packet Service (PS) domain billing. CS domain adopts circuit switching, so call duration becomes the primary factor of billing. PS domain data works in packet transmission, so traffic is the primary factor of billing, but time is not excluded. This chapter mainly introduces the billing principles of CS domain and PS domain, including the billing architecture of core network, bill generation mechanism and processing course. 

8.4 Introduction to Common NMS Interfaces


8.4.1  Reference Models for Common NMS interfaces


Generally, the interfaces between the NE and the OS within a UMTS network include:
l   The interface between the NE and the NE management layer;
l   The interface between the NE management layer and the network management layer;
l   The Interface between different NMSs;
A reference model for common 3G NMS interfaces is shown as the figure below:
The NMS interface Itf-N may be the interface between NM and EM or between the NM and the NE.

As NM equipment of EML layer, iManager M2000 provides interfaces with the NE and the upper NMS. The interface with the NE may be called southern interface, which is usually an internal MML interface. The interface with the upper NMS may be called northern interface, which is usually a standard interface or an interface negotiated with the upper NMS (the third-party NMS). Among the common NMS interfaces are the CORBA interface and the core database interface.

8.4.2  Common NMS Interfaces

1. CORBA interface

1)      Introduction to the CORBA
The Common Object Request Broker Architecture (CORBA) is a solution proposed by the Object Management Group to meet the ever increasing demands for the collaboration capability of software and hardware. With ORB, the customer may easily use the server object methodology, no matter whether the servers are located on the same computer or accessed via a network. ORB captures and invokes, and then finds out an object to deliver the request. Then, it transfers parameters and methods and finally returns the result. When ORB is used, a protocol is defined using the application interface, which is implemented by the Interface Definition Language (IDL).Customers neither know where the object is nor what language is used for its implementation, nor the OS and anything else irrelevant to the object interface.
2)      Importance of the CORBA interface
At present, the telecom NMS tends to embrace integrated technologies. As one of the leading NMS technologies, TMN gives a good idea for the construction of integrated NMS. However, TMN does not go into detail when it comes to how to construct a management system and how to provide interoperability among the management systems. Luckily, CORBA has now become a mature distributed object-oriented technology. Given the open telecom market environment, CORBA is tailor-made for fast service construction and the effective management of resources and services. In the field of NMS, to integrate the TMN with the CORBA technology is the most ideal solution up to date to building a comprehensive NMS.
Now, both the International Standardization Organization (ISO) and the International and Regional standardization Organization have treated the CORBA interface as an important interface in the filed of telecom NMS.ITU-T takes the CORBA interface as a way to provide general Q interfaces. The interfaces defined by TMF are basically CORBA interfaces. The 3G interfaces defined by 3GPP are mostly CORBA interfaces together with CMIP interfaces. Thus, the CORBA interface may be considered a leader in the field of telecom NMS.

2. Core Database Interface (Core DB)

The Core Database Interface means that the visited party (like M2000 system) makes known the structure and fields of related database in the system, allowing a third-party vendor to visit and access the database directly.
Such interface mode is widely applied to interconnection with the upper NMS. Third-party vendors usually develop application programs for access according to the open database. Generally, write operation is not allowed to. The method features fast interconnection and easy interface negotiation. Its disadvantage is the security problem with the released undertaking high risks.

Before the CORBA interface standard is fully operational, open core database is also common for interconnection with the upper NMS.

8.3 Introduction to the Service Features of the 3G NMS


The service features of the 3G NMS include:
l   Performance management
l   Roaming management
l   Fraud management
l   Position management
l   Fault management
l   Security management
l   Software management
l   Configuration management
l   Accounting management
l   Order management
l   Quality of Service (QoS) management
l   User equipment management

8.3.1  Performance Management


Throughout the life cycle of the 3G network, both the logic and the physical configurations must be more or less modified to optimize network resources. All these modifications are made through network configuration and network engineering.
Many routine maintenance activities and future network planning of the 3G network require basic decision data, that is, network load and qualify of service. To generate such data, it is required to measure the performance of the NEs that make up the network, and then transfer these data to the external operation support system for further analysis.
3GPP’s performance management function area is intended to measure the cross-3G network performance (i.e. ranging from the access layer to the service provisioning layer) and collect the performance measurement data. It defines the management of the measurement plan for the element manager system, the generation of the NE measurement results and the transfer of results to one or more operation support systems. Below are the objectives:
l   To define a standard measurement set
l   To define universal management technologies for measurement maintenance & management and result accumulation;
l   To define the method of batch transfer of the measurement results on the management interfaces;
For details, please refer to 3GPP TS32.104.

8.3.2  Roaming Agreement Management


In order for subscribers to use the services provided by a non-home service provider, a roaming agreement/contract should be reached between the home service provider and the non-home service provider. The roaming agreement can either be an agreement between two operators (known as “bilateral agreement”), or a “clearing house” (known as “multilateral agreement”). Under the roaming agreement, the home service provider is the customer, while the non-home service provider acts as the supplier.
Regardless of whether a bilateral or multilateral roaming agreement, it must at least set out the following terms:
l   Tariff/price
l   Interconnection between signaling and service
l   Bill interchange format and plan
l   Troubleshooting
The roaming agreement will affect many aspects of the network and the operation management infrastructure, like the follows such as service implementation, service assurance and service charging in the operation system.

8.3.3  Fraud Management


Frauds as well as measures to detect and guard against these frauds are not unusual for any network. However, mobile and roaming services together make the fraud detection and prevention even more complex and urgent. Things would become even worse when the mobile service provider does not know how to locate the fraudulent customer during roaming. The roamer is not a customer of the service provider, so the service provider has no information enough to check whether a fraud exists.
On the other hand, the service provider could hardly control the roamer’s activities, such as credit card overdraft and service suspension. In such a situation, the customer can commit a fraud on the network of another service provider, that is, the home service provider has to count on the fraud detection level of the roaming service provider. This means, to a great extent, neither the home service provider nor the roaming service provider can control the subscriber properly.
Typical fraud management over the mobile network provides at least the following functions:
l   To classify the subscribers according to the level of fraud risk, which is based on demographic statistics and credit information;
l   To revise the risk level according to the utilization and the payment (in real time or near real time);
l   To detect and sample the frauds in real time or near real time;
l   To take measures to suspend the service, even when the customer is roaming on a network other than the home network;
l   For visiting customers (the roamer), the roaming service provider may consult the home network provider or the international knowledge base to assess the potential fraud, so as to decide whether to allow the roamer to access the network.
The fraud management service addresses the following three areas: fraud detection, fraud termination and fraud prevention.

8.3.4  Configuration Management


A real 3G network consists of various devices of different suppliers, and the operator should manage these network devices properly to guarantee QoS (quality of service) the customers has expected. The most important thing is the standardization of 3G system configuration management, so that the networks of multiple providers can more or less operate properly and effectively.

1. Requirements of the 3G network configuration management:

l   To enable operators to make configurations as fast and accurately as they could, so as to avoid long-time wait and complex configuration;
l   To ensure the configurations will not cause any adverse impact on the NEs that need no configuration.
l   To provide a mechanism to prevent the configurations from affecting the communication-related services.
l   To provide a mechanism to avoid data inconsistency, e.g. record the revision reason or restore the updated data.
In brief, these principles involve security, data validity and consistency as well as resource maintenance.

2. For configuration management, the system is expected to provide the following capabilities for the operator:

The management system provides the following capabilities through its service components:
-Modify system , change the network to meet the operator’s requirements
l   Create NE/network resource;
l   Delete NE/network resource;
l   Modify NE or network resource;
- Monitor the system, obtain an overview of current software, equipment and data;
l   Information inquiry;
l   Information reporting;
l   Control over the response/reporting;

8.3.5  Fault Management


The fault management comprises a series of (sub-) processes such as fault detection, fault location, fault reporting, fault correction and fixing. These (sub-) processes are distributed on different management layers, but most procedures (like fault detection, fault location, fault correct and fault fixing) are mainly located on the NE and the NE management layer so that the network equipment is capable of “self-healing”.
Logically, the network data management function is about how to collect and use the performance and service data. When the NE gets faulty, the fault management feature of the NE management layer is the leading responder, while the network and the system management layer makes a preventive response.

8.3.6  Accounting Management


The 3GPP billing data mainly describes the following:
l   Planning and formatting bills of the 3G core network (circuit packet switching and IP multimedia) node and the service node (multimedia short message service). Please refer to [14].
l   For call state data generation, billing event and other service requirements, please refer to 3GPP TS 22.115.
l   CDR format and file transfer mechanism formally described in ASN.1 language.
For the specific billing requirements of each 3G area, please refer to 3GPP TS 22.115 and TS 32.105.For the specific billing data of each area, please refer to 3GPP TS 32.205, TS 32.215, TS 32.225 and TS 32.235.

8.3.7  Software Management


In the 3G network, the software management covers host software management processes and software fault management. The host software management processes consist of software request, receiving, installation, monitoring, documentation, database update and feedback to the supplier. The sub-process is also applicable to the whole software release and the installation of patches for defective software of the NE/element manager system. The software fault management focuses on the monitoring and troubleshooting of network faults resulting from software failure.

1. Host software management process

It refers to the management of new software and patch release. It is very important to ensure high QoS of the network without interrupting existing services during new software integration on the network. The main steps of this process are:
l   Delivery of the software by the supplier
l   To deliver the software to the NE/element manager system for local storage
l   To verify the validity of the software to ensure the software is not misused
l   To activate the software
l   To verify the validity of the software to ensure the software can run properly
l   To accept or reject (in the case of changes to software of previous versions) the software according to the verification result

2. Software fault management

The software fault management involves the following steps:
- To check software fault/failure on the network
- To analyze the problems, to determine the root cause of software failure and the necessary corrective measures. The measures that may be taken include:
l   To roll back to previous version through loading or activation
l   To load and activate correct software
l   To restart current software

8.3.8  Security Management


Similar to the 2G network, the security management feature of the 3G network is also to guard the system against malicious attacks, in order to ensure stable network operation. Generally, the network security is ensured by an ideal authentication mechanism. This function is in fact the application of the service layer or the application layer.
It should be noted that the 3G network trends towards full-IP network, so the IP security assurance mechanism is even more important for the security of 3G network. Generally, the O&M IP network is considered unsafe due to its scale, complexity, limited physical security and the possibility of remote access through dialup or Internet. Thus, the only way out for security is to logically isolate the O&M IP network from the Internet. Largely, the IP infrastructure is secured with basic IP features, such as the address mechanism, DNS, DHCP, BOOTP and the firewall. These features mainly serve to protect the network layer.

8.3.9  QoS Management


In the 2.5G/3G network, the QoS management mainly provides two functions: QoS policy provisioning and QoS policy monitoring. The QoS policy provisioning refers to the process of configuring and maintaining the selected NE according to the QoS policy generated on the basis of the SLAs and the observed network performance. The QoS policy monitoring is the process of collecting the QoS performance statistics and the alarm data. The collected performance data is used to generate the analysis report, based on which the network will be changed or upgraded.
In the 2.5G/3G network, the network domains must interact to achieve end-to-end service quality for end user applications. To achieve the QoS required by a network operator, all the NEs from various network infrastructure suppliers should be configured in the same way, adding to the complexity of interaction. NEs must be configured with many QoS functions, such as admission controller, policy manager, shaper, queue manager and scheduler. To configure these heterogeneous networks to provide expected QoS, the operator needs a management solution satisfying the following high-level requirements:
l   Automation of management tasks
l   Centralized management to reduce the types of management interfaces
l   Abstracting and simplifying the management data
l   End-to-end network provisioning
l   Consistent and unified provisioning over all NEs
l   To allow interoperation between the NE and the OSS, a standard-based solution is needed
l   Scalability of the solution for large networks

1. QoS policy provisioning on the NML layer

The QoS policy provisioning on the NML layer serves to provide network-level operation support for network-wide policy management points. It includes the following functions:
l   To be the user interface for the network policy maintenance
l   To be the master network policy base to store all the network policies of all domains
l   Capability to assign policy data to the EML policy server
l   To detect global policy conflicts
The policy base adopts the LDAP-based directory to store the policy information.

2. QoS policy provisioning on the EML layer

The QoS policy provisioning on the EML layer provides NE management function for the policy management point of the network domain. A domain refers to a network section that contains devices used to implement logic-related functions. Among network domains are the access network, the core network and the transmission network.
QoS policy provisioning on the EML layer provides the following functions:
l   To be the optional user interface for the policy maintenance of the EML layer
l   To be the particular policy base of the EML layer
l   To assign the policy data to the policy decision point
l   To detect local policy conflicts
It is clear that the optional EML-level user interface for policy maintenance is necessary on the small networks without network-level policy provisioning support system.
It should be noted that the EML-level policy base includes the policy used in this domain, as well as the general network policy across domains.

3. Policy Decision Point (PDP) and Policy Enforcement Point (PEP)

The Policy Decision Point (PDP) is the point to determine the policy of the policy enforcement point under the network’s control. So, the PEP is a function in the network node, while the PDP may be an independent functional entity that resides in a standalone policy server (like the application server). The PDP will make decisions according to the policy information in the policy base.
The Policy Enforcement Point (PEP) is the functional part of the network element that implements the policies defined in the policy management system. It includes the following functions:
l   To store the data related to the local policy
l   To enforce the policy according to the network conditional command
l   To support the policy mechanism of differential services
At the beginning, the PED will request the PED of its parent node to download all the policy data necessary for the operation.

4. QoS monitoring

In the 2.5G/3G network, the QoS monitoring functionality is intended to collect/process such data as performance statistics, utilization data and QoS-related faults. For end-to-end QoS monitoring, the QoS monitoring process should be included in the NE, the network element management layer and the network management layer. Alarms and performance data are collected at the NE layer, while the convergence, reporting and analysis of alarm data and performance data are performed at the network element management layer and the network management layer.
The process of QoS monitoring provides the following functions:
l   To manage QoS fault information from NEs
l   To query QoS performance data from NEs
l   To collect and process utilization data
l   To analyze the key QoS parameters to generate a QoS report
l   To audit/analyze the collected QoS parameters by comparing them with the expected values.

In fact, the above service features required in the 3G NMS may not be provided at a specific service layer. To deliver a specific service feature, several layers or even various networks must work together, share information and invoke services among one another, to develop an integrated solution. The principle of 3G network construction is to build an open, multi-layer and highly scalable network with an integrated architecture.

8.2 NMS Basic Principle


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 OSS 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.
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 3G NMS architecture

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 Enterprise 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 system.

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 Enterprise 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.
Interface 3: It means the interface between OSs. 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;
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 develop services.

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 2G NMS.
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 3G NMS is more reasonable than that of the 2G NMS
The 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 (OSS layer), where services are not well integrated.
The 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
In the 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.
The 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 OSS layer, to develop an integrated O&M solution.
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
In the 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.

4. The 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 3G 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 intricate;
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 devices;
Thus, the 3G NMS manages various service areas through different layers.

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.
l   - One-stop charging for all services