Characteristics – O&M

SGSN9810 supports abundant and flexible operation and maintenance.

-3 ways of O&M, LMT ( Local Maintenance Terminal), integrated O&M via iManager M2000, and NMS.

-2 ways of configuration, dynamic and static data configuration.

-Managing SGSN9810 by status query, status control and testing.

-Interface tracing and user tracing functions are combined in the O&M system.

-Real-time performance measurement and management, task management, and custom-built measuring indices.

-Detail alarm and location information, flexible and easy alarm handing.

-2 ways of SGSN9810 system security, authority management and operation log management.

Detail online help documentations.
Features

Physical Ports Capability

Functions – Gb over IP

SGSN9810 support both Gb over FR and Gb over IP.

-In 3GPP, it specify the Network Service (NS) layer can be carried by a frame relay network or an IP network.

-In a Gb over IP network, a NS-VC is defined by  a quadruple consisting of the SGSN IP address, SGSN UDP port number, BSS IP address, and BSS UDP port number. 

Functions – Differential Service

The differential service enables operators to define priorities for subscribers in which resources are controlled  depending on users priorities.

Subscribers are grouped into three classes according to their priorities:

-Special subscribers

-High-end subscribers

-Common subscribers

Operators can offer different services to different subscribers through the following two methods:

-Specifies the threshold of  MM  resources usage to limit the attach and routing area update (RAU) of some subscribers.

-Specifies the threshold of SM resources to limit certain services (PDP contexts) of some subscribers. 

Functions - Handover Strategy Control

The handover strategy control helps operators in distributing traffic and balancing service load between 2G networks and 3G networks.

This function is applicable to the 2G and 3G supportive terminals that are allowed to access 2G/3G network.

When a terminal is in a 3G network,. The handover strategies include:

-Handover to 2G network recommended

-Handover to 2G network not recommended

-Stay in the 3G network

When a terminal is in a 2G network,. The handover strategies include:

-Handover to 3G network recommended

-Handover to 3G network not recommended

-Stay in the 2G network

SGSN Functions - SIGTRAN

The Signaling Transport (SIGTRAN) protocol stack is defined by (IETF) to enables an IP network to transfer the signals of a traditional switched circuit network (SCN). 

Functionally, the SIGTRAN protocol stack is classified in the following two types:

[General signaling transmission protocols : The Stream Control Transmission Protocol (SCTP)

− which realize the reliable transmission of SS7 signaling messages on an IP network.

[SS7 signaling adaptation protocols : M2UA/M3UA/ IUA/V5UA

−which are designed to adapt the various signaling protocols used by the SCN. 

Functions – NTP Client

NTP (Network Time Protocol)

NTP is a TCP/IP protocol used to broadcast the precise time in the entire IP network. The transmission itself is based on UDP

-The RFC1305 standard defines the algorithm used by the NTP, to ensure the accuracy of the clock synchronization.

The Huawei SGSN9810 supports setting the remote server as the local time server. The local peer works in client mode.

Functions - NACC (Network Assisted Cell Change)

When the MS initiates a cell reselection between the BSCs during the data transmission, NACC function reduces the time delay of the cell reselection greatly and improves the QoS.

 Generally, it maintains the service interruption within 300 ms to 700 ms, rather than 1 second or 2 seconds without applying this function.

To assist fast cell reselection, the MS needs to know the system information of the target cell before cell change.

[If the target cell belongs to another BSC/RNC, In this case, the system information is included in the RAN-INFORMATION message, and then sent to the target BSC/RNC by SGSN.

SGSN Functions - MVNO

MVNO: Mobile Virtual Network Operator

[MVNO can use another Mobile Network Operator (MNO) to provide its services 

[MVNO enables multiple operators invest on the sharing network, or rent other operator’s network, to lower the investment and risk.

[The network resource authorized by the MNO can be RAN, partial CN and the whole CN. 

SGSN Functions – RAN Sharing in Connected State

-Ran sharing can be applied to cover a large area in which each operator can cover a part from this network 

-In case  there is an overlap area, the UE of operator B must access the RAN of operator B rather than the LA/cells of operator A.

-To put a rule for this case, the R5 protocol introduces the concept of shared network area (SNA). A SNA is an area corresponding to one or more RAs which control the UE access.

-The SNA is configured in CN whereby The CN provides the SNA ID list which contains the sharing network areas the UE can access .

-If the RA is part of the SNA that the UE can access, the UTRAN allows the UE to access. Otherwise, the UTRAN denies the access.

SGSN Functions – Iu-FLEX/Gb-FLEX

This function  refers to the function of one RAN/BSS connecting to multiple CN nodes within the same area.

 

pool-areas are a set of one or more RAN/BSS node service areas served by multiple CN nodes (MSC or SGSN) at the same time.

The Iu-FLEX/Gb-FLEX function  reduces the efforts of inter-CN-node update/ switch/relocating and HLR update.

This function also enhances the availability of the system , If one CN node in the pool-area is faulty, other nodes can provide services.

SGSN Functions - QoS

SGSN9810 supports the four classes of QoS services : conversational, streaming, interactive and background defined by 3GPP through the following ideas:

Access control

−The SGSN can deny the MS access if QOS negotiation fails

QoS queue management

−Data packets are scheduled according to  their different QOS

Differential service (DiffServ)

−In the DiffServ system, the network node determines the per-hop behaviors (PHB) according to the differentiated services code point (DSCP) of the IP header.

QoS mapping

−Mapping between QoS requirements  for different protocols & versions

CAR and remarking

−In case data packets exceeds the requested QOS ; SGSN can apply CAR or remarking procedure for controlling this

SGSN Functions - Billing

SGSN9810 generates and sends these CDRs to CG by Ga interface:

-S-CDR: Records the relevant information of the PDP context in the SGSN.

-M-CDR: Records the relevant information of the mobility.

-S-SMO-CDR: Records the information of mobile originated SMs.

-S-SMT-CDR: Records the information of the mobile terminated SMs.

-LCS-MT-CDR: Records the information of the mobile terminated location service.

-LCS-MO-CDR: Records the information of mobile originated location service.

-LCS-NI-CDR: Records the information of network originated location service.

SGSN Functions – IPSec and LLC Encryption

IPSec

-The SGSN9810 encrypts the Gn/Gp interface signaling through IPSec.

-IP security (IPSec) is layer 3 encryption protocol developed by the IETF.

- It ensures the security of the data transmission  through encryption and authentication.

LLC Encryption

-In the 2.5G system, the logical link control (LLC) layer encryption between the MS and the SGSN is the traditional stream encryption.

- The algorithm is the GEA1 and GEA2 algorithm whereby the data to be encrypted includes the information field and the authentication field carried by the LLC frame.

SGSN Functions - Routing

Static routing

-Static routing is configured manually to improve network performance and ensure the bandwidth for the critical applications.

OSPF V2/V3

-Open Shortest Path first is an internal gateway protocol based on the link status. It has obvious features such as large scope, fast convergence, loop free, area division, equal cost route, hierarchical routing, verification and group broadcasting.

RIP II

-Routing Information Protocol is easy to implement and the cost has little impact on the network performance. It’s widely used in the networking.

SGSN Function-MM & SM

Functions – MM & SM

Mobility Management (MM)

-MM  is to control the MS Authentication / accessible services the GPRS/UMTS network

- MM is used trace the current location of the MS such as the RA and Cell ID.

-The MM function is realized mainly by attachment / detachment and route updating.

Session Management (SM)

-SM carries out packet data protocol (PDP) context management. The PDP context is a group of information describing all the information related to the data sessions accessed by the MS

-The session management includes PDP context activation, modification and deactivation.

-The NEs such as MS, SGSN and GGSN sends and manages the PDP data based on the PDP context.

SGSN Service

Services – IP/PPP Bearer Service

SGSN9810 support IPv4, IPv6 and PPP protocol. The IP/PPP datagram can go through the GPRS/UMTS network transparently.

The applications can be web browsing, FTP, VPN and so on.

Services – Short Message Service

SMS services can be applied through CS or PS

-Depend on the MM status IMSI/GPRS attached

- Normal SM can contain up to 160 bytes including control bytes.

- Enhanced SM contains text and style, including objects such as animations and picture. One enhanced SM may contain more than one object..

Services –Location Service

Location service

-Location service provide the location of the MS in the telecommunication system. It can provide various services based on the MS location such as emergency call, navigation, and so on. 

Services – CAMEL Phase 3

CAMEL Phase 3

-CAMEL (Customized Application for Mobile network Enhanced Logic) is a tool to help the operators providing the users with the special services such as pre-paid service.

-AMEL Phase 3 provides the intelligent control of PS service, intelligent control of short message service, and so on. 

Services – Lawful Interception

Lawful Interception

-Lawful interception refers that the Third generation mobile communications system (3GMS) provides the content of communication (CC) of the MS and the intercept related information (IRI) to the law enforcement agency (LEA). 

SGSN System

Advanced Platform
-SGSN9810 adopts large capacity and high degree of integration platform. When fully configured, it needs five cabinets in a 2.5G network, or three cabinets in a 3G network.

-The use plane data of SGSN9810 is forwarded using hardware, which improves the processing efficiency and integration of the system.

High Reliability

Critical data auto-backup

-Automatically backup the configuration data, performance data, and operation logs.

Safe operation

-Users’ management authority and authentication.

CG relocating and bill buffering

Redundant hardware design

-All major boards adopt 1+1 or N+1 backup or Load sharing.

Accident protection

-System power-off protection, system power lighting protection, voltage out of range protection, E1/T1 link lighting protection, etc.

System overload control

-Automatically adjust the data flow smoothly to avoid system break down due to overload or resource congestion.

Board LOCK and system SHUTDOWN

-Guarantee the services slowing existing the boards or the system to avoid service sudden interruption.

Handle in MS

MS start and send “Active PDP context request” to SGSN

-Provide QoS parameter

-Provide a APN-NI

-Provide a static IP or null

Receive  ACCEPT from SGSN

-If the QoS not accept by MS, then starts delete PDP context procedure.

Handle in SGSN

Check subscriber data

APN selection

-According to TS 23.060

-default APN,APN provide from MS and the APN subscribed in HLR

-APN-NI.APN-OI

Interrogate DNS

-Hostfile/Cache/DNS server

QoS negotiation

-QoS provided from MS, default QoS ,QoS subscribed in HLR

Send message “create PDP context request” to GGSN

RAB assignment

Send message “active PDP context accept” to MS

-Dynamic IP address

-QoS

Handle in GGSN

Check the APN provided by SGSN

QoS negotiation

Allocate a dynamic IP to the MS

Allocate a charging ID for the PDP context

Return a CREATE PDP CONTEXT ACCEPT message to SGSN

-Dynamic IP

-QoS

-Charging ID

-Other information

Update PDP context

Activation Procedure

PDP context  activation procedure

-To establish a PDP context between the MS and the SGSN, the

GGSN

Important Concept __ APN

Important Concept __ APN

APN structure: APN_NI+APN_OI 

Operator ID : fixed extension, must end with “.gprs”

Network ID shall not end with “.gprs”

MM Context and PDP Context

Important Concept __ PDP Type and PDP Address

PDP Type

-IPV4

-IPV6

-PPP

PDP Address

Static IP

−Public IP

−Allocate by the operator

Dynamic IP

−Private IP

−Allocate by GGSN, DNCP or Radius

Important Concept __ QoS

QoS is quality of service

It is a group of parameters that can define the network ability, such as the bit rate for downlink or uplink data transmission and the reliability class and so on

It is end to end concept

PDP Context

PDP Context

-The PDP context is Packet Data Protocol context

-PDP context contains all the information needed to transfer user data between MS and GGSN.

-The context includes parameters such as Routing, QoS (Quality of Service), Charging ID etc.

-PDP context exists in MS, SGSN, GGSN and RNC/BSS

Session Management

Function

[Establish and monitor a packet tunnel from MS to GGSN, and allocate system resource for the packet service.

Important Procedure

[PDP Context Activation

[PDP Context Modification

[PDP Context Deactivation