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.

Комментариев нет:

Отправка комментария