ZXUR 9000 GSM
Base Station Controller
Product Description
Version: 6.50.00
ZTE CORPORATION
NO. 55, Hi-tech Road South, ShenZhen, P.R.China
Postcode: 518057
Tel: +86-755-26771900
Fax: +86-755-26770801
URL: http://ensupport.zte.com.cn
E-mail: support@zte.com.cn
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The ultimate right to interpret this product resides in ZTE CORPORATION.
Revision History
Revision No.
Revision Date
Revision Reason
R1.0
2011–04–25
First edition
Serial Number: SJ-20101019110320-002
Publishing Date: 2011–04–25(R1.0)
Contents
About This Manual ......................................................................................... I
Chapter 1 Product Overview ..................................................................... 1-1
1.1 Product Context ................................................................................................. 1-1
1.2 Whole Cabinet Appearance ................................................................................ 1-2
1.3 Product Features................................................................................................ 1-2
1.3.1 Advanced System Architecture.................................................................. 1-3
1.3.2 A Software Platform of High Scalability ...................................................... 1-4
1.3.3 Higher Capability for Service Processing ................................................... 1-4
1.3.4 The Carrier-Class Reliability...................................................................... 1-4
1.3.5 Environment-Friendly Design .................................................................... 1-4
1.3.6 More Competitive Evolution Potential ........................................................ 1-4
1.3.7 2G/3G Handover Compatibility .................................................................. 1-4
Chapter 2 Service Functions and Technical Specifications................... 2-1
2.1 Service Functions............................................................................................... 2-1
2.1.1 Basic Services ......................................................................................... 2-1
2.1.2 Mobility Management ............................................................................... 2-7
2.1.3 Channel Management .............................................................................. 2-8
2.1.4 External Interface ..................................................................................... 2-8
2.1.5 Radio Resource Management ................................................................... 2-9
2.1.6 Network Management Functionality ......................................................... 2-10
2.2 Technical Specifications.................................................................................... 2-10
2.2.1 Physical Specifications ........................................................................... 2-10
2.2.2 Power Specifications .............................................................................. 2-10
2.2.3 Backup Configuration ..............................................................................2-11
2.2.4 Environment Requirements......................................................................2-11
2.2.5 Security Specifications............................................................................ 2-13
2.2.6 Interface Specifications........................................................................... 2-13
2.2.7 Capacity Specifications........................................................................... 2-14
2.2.8 Clock Specifications ............................................................................... 2-14
2.2.9 Reliability Specifications ......................................................................... 2-14
Chapter 3 Product Structure ..................................................................... 3-1
3.1 Logic Structure................................................................................................... 3-1
3.1.1 System Logical Structure .......................................................................... 3-1
I
3.1.2 System Logical Units ................................................................................ 3-1
3.2 Hardware........................................................................................................... 3-3
3.2.1 Cabinet Structure ..................................................................................... 3-3
3.2.2 Subrack Structure .................................................................................... 3-4
3.2.3 Front Boards ............................................................................................ 3-6
3.2.4 Rear Boards ............................................................................................ 3-7
3.3 Software ............................................................................................................ 3-9
3.3.1 NE Software and the EMS ........................................................................ 3-9
3.3.2 Classification of NE Software .................................................................. 3-10
Chapter 4 Networking ................................................................................ 4-1
4.1 Networking via the Abis Interface ........................................................................ 4-1
4.1.1 Star Networking ....................................................................................... 4-1
4.1.2 Chain Networking..................................................................................... 4-1
4.1.3 Ring Networking....................................................................................... 4-2
4.1.4 Star-Chain Hybrid Networking .................................................................. 4-2
4.2 Networking via the A/Gb Interface ....................................................................... 4-3
4.2.1 Networking via the Gb Interface ................................................................ 4-3
4.2.2 Networking via the A Interface................................................................... 4-4
Chapter 5 System Configuration............................................................... 5-1
5.1 Configuration Description.................................................................................... 5-1
5.2 Board Configuration ........................................................................................... 5-2
5.3 Subrack Configuration ........................................................................................ 5-3
5.3.1 Typical Configuration for Single Service Subrack........................................ 5-3
5.3.2 Typical Configuration for Double Service Subracks..................................... 5-3
5.3.3 Typical Configuration for Triple Service Subracks ....................................... 5-4
5.4 Cabling Configuration ......................................................................................... 5-5
5.5 Configuration of Network Management Software .................................................. 5-6
Chapter 6 Signal Processing Flow............................................................ 6-1
6.1 Circuit-Switched User Plane Data ....................................................................... 6-1
6.2 Packet-Switched User Plane Data ...................................................................... 6-2
6.3 Control Plane Signaling ..................................................................................... 6-2
6.4 BTS Operation and Maintenance Data................................................................. 6-3
Chapter 7 Reliability ................................................................................... 7-1
7.1 Hardware Reliability Design ................................................................................ 7-1
7.1.1 Types of Board Backup............................................................................. 7-1
7.1.2 Supported Backup Mode for Different Boards............................................. 7-1
7.2 Software Reliability Design ................................................................................. 7-2
II
7.3 Heat Dissipation Design...................................................................................... 7-3
7.3.1 Introduction to Heat Dissipation................................................................. 7-3
7.3.2 Air Duct for Heat Dissipation ..................................................................... 7-3
Figures............................................................................................................. I
Tables ............................................................................................................ III
Glossary .........................................................................................................V
III
IV
About This Manual
Purpose
ZXUR 9000 GSM is a new generation radio network controller (that is, BSC) in the ZTE 2G
multi-mode series products. It performs functions including system access control, security
mode control, mobility management, and radio resource management and control.
ZXUR 9000 GSM provides all the functions defined in the 3GPP R4/R5/R6/R7 protocols,
and offers series standard interfaces including A-interface, Abis interface, and Gb
interface, which enable it to connect with CN, BSC, and BTS. ZXUR 9000 GSM is
developed on the basis of ZTE all-IP unified hardware platform. It features a distributed
design, separating control plane and user plane as well as interface and application. It
supports TDM/IP dual protocol stack, and can smoothly evolve into all-IP GERAN.
What Is in This Manual
Chapter
Description
Chapter 1, Product
Introduces the context of ZXUR 9000 GSM, the cabinet appearance,
Overview
and the features provided.
Chapter 2, Service
Describes the service functions and technical specifications of the
Functions and Technical
product.
Specifications
Chapter 3, Product
Describes the logical structure, the hardware, and the software of the
Structure
product.
Chapter 4, Networking
Describes different networking modes with illustrations.
Chapter 5, System
Presents three typical configuration scenarios with illustrations.
Configuration
Chapter 6, Signal
Illustrates the signal processing flow on the user plane, control plane,
Processing Flow
and the BTS operation and maintenance data flow.
Chapter 7, Reliability
Presents hardware backup modes and the heat dissipation design.
Intended Audience
Communication engineers
I
II
Chapter 1
Product Overview
Table of Contents
Product Context .........................................................................................................1-1
Whole Cabinet Appearance........................................................................................1-2
Product Features........................................................................................................1-2
1.1 Product Context
ZXUR 9000 GSM is part of the GSM/EDGE Radio Access Network (GERAN). The GERAN
includes one or more Base Station Subsystems (BSSs), each of which is made up of one
BSC and one or more BTSs. The BSC and the BTS are connected via the Abis interface,
while the GERAN and the CN are connected via the A/Gb interface.
The network location of ZXUR 9000 GSM (BSC) and its relations with other network
elements are shown in Figure 1-1.
Figure 1-1 The Context of BSC
The external system and interfaces are illustrated in Table 1-1.
Table 1-1 The External System and Interfaces
External System
Function
Related Interface
BTS
Establish the radio environment and
Abis
transport data under the control of BSC.
MSC/MGW
Connect BSC with MS to establish radio
A
voice channel for voice switching.
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External System
Function
Related Interface
SGSN
Connect BSC with MS to establish PS
Gb
radio channel for data switching.
1.2 Whole Cabinet Appearance
ZXUR 9000 GSM adopts the standard 19-inch cabinet. The whole cabinet appearance is
shown in Figure 1-2.
Figure 1-2 ZXUR 9000 GSM Cabinet
1.3 Product Features
ZXUR 9000 GSM is a radio network controller developed by ZTE according to 3GPP R7.
With all functionalities specified by 3GPP R7, the product provides a series of standard
interfaces and supports connectivity with the CNs from different manufacturers. The
product features high capacity, high reliability, with high-scalability. It also supports IP
GERAN transmission.
l
High Scalability
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Chapter 1 Product Overview
ZXUR 9000 GSM is adaptable to service growth and different traffic volumes,
providing high-capacity and high-scalability. The resource-processing capacity on
both the user plane and the control plane can be expanded as required.
l
High Capacity
ZXUR 9000 GSM is committed to shortening the investment made by customers in
the entire 2G product lifecycle and providing large-capacity one-stop products.
l
High Reliability
ZXUR 9000 GSM has high reliability. Backup is supported for all components, with
online software downloading provided.
l
High-efficiency Radio Resource Management
ZXUR 9000 GSM supports automatic optimization of radio parameters. Moreover,
radio resource priority allocation and scheduling can be performed intelligently
according to the network load and QoS level.
l
Flexible Networking
ZXUR 9000 GSM supports Abis interface-based star network, chain network, tree
network, and ring network. The product is also compatible with transmissions through
the Ethernet, E1/T1, and optical fibers.
l
Variety of Interfaces
The BSC supports TDM/IP, and such physical interfaces as E1/T1, CSTM-1, Ethernet
FE/GE. These interfaces make flexible networking possible.
The BSC adopts IP-based switching platform. IP-based architecture makes data
transmission highly effective and flexible. Moreover, high performance packet data
processing platform ensures the unblocked data switching capability. Compared
to TDM architecture, IP-based switching has the advantages of convenient
maintenance, easy configuration, flexible expansion, highly efficient transmission
with flexible transmission mechanism. Therefore, it is more adaptable to rapidly
developing mobile data services in the future.
1.3.1 Advanced System Architecture
The ZXUR 9000 GSM system is based on the ATCA architecture, providing a
standard-platform architecture with features like high reliability and maintainability for
carrier-class applications.
The service control unit adopts standard ATCA architecture.
The media access unit adds several rear boards to ATCA. With the capacity of original front
boards, the added rear boards can improve the processing capacity with more interfaces.
The rear boards can be fully utilized to meet the requirements of relatively large amount
of low-speed interfaces for a BSC.
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1.3.2 A Software Platform of High Scalability
The system software adopts the Linux multi-process architecture. The middleware concept
is introduced for restructuring software design to enable a highly cohesive system with
loose coupling.
The multi-process architecture ensures the independence of individual processes,
separating the errors occurring within one process from others.
1.3.3 Higher Capability for Service Processing
ZXUR 9000 GSM is a highly integrated system with great processing capability, which
provides the operator with strong competitiveness in the mobile Internet era.
1.3.4 The Carrier-Class Reliability
ZXUR 9000 GSM adopts a modular design that facilitates installation and maintenance
and makes capacity expansion or adjustment flexible. With good strength and rigidity, the
cabinet will hardly become loose, deformed, or damaged during installation/uninstallation,
storage and transportation. Besides, the cabinet structure has well-designed cooling and
good electromagnetic compatibility (EMC).
1.3.5 Environment-Friendly Design
The system is designed by observing relevant environment preserving regulations and
standards. The increasing energy tense and ever deteriorating environment have made
environment-friendly design and low power consumption important concerns for telecom
operators, who not only take environment preservation a social responsibility and a means
for reducing cost, but also promote the formulation of relevant regulations and standards.
1.3.6 More Competitive Evolution Potential
ZXUR 9000 GSM has more competitive evolution potential, which can be explained by the
following features:
l
l
l
varieties of external interfaces that are compatible with both full-IP requirements and
traditional E1 and TDM access.
compatible with IPV6
compatible with future development: the media access system considers the
operator's investment benefit in that it is compatible with multi-mode application and
the evolution to 3G.
1.3.7 2G/3G Handover Compatibility
The ZXUR 9000 GSM system provides handover between 2G and 3G networks in both
the CS domain and PS domain. This feature can reserve the investment in 2G network
and provide 3G handover capability for 2G operators.
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Chapter 2
Service Functions and
Technical Specifications
Table of Contents
Service Functions.......................................................................................................2-1
Technical Specifications ...........................................................................................2-10
2.1 Service Functions
2.1.1 Basic Services
ZXUR 9000 GSM supports the service functions of the BSC specified in GSM Phase II+
standards, while compatible with GSM Phase II standards. The major functions are listed
as follows:
1. Supports GSM900, GSM850, GSM1800 and GSM1900 network.
2. Connects with NetNumen M31 via the OMC interfaces for the management of BSS(s).
3. Supports various types of services, including
a. Circuit-Switched Voice Services
l Full Rate (FR) Speech Service
l Enhanced Full Rate Speech Service
l Half Rate (HR) Speech Service
l AMR Speech Service
Adaptive Multirate (AMR) technique is a kind of speech coding algorithm with
variable rates. It can automatically adjust speech coding rate based on C/I
value, thus ensuring the best speech quality for different C/I values.
According to relevant protocols, AMR-FR speech coder has 8 rate modes,
which are all supported by ZXUR 9000 GSM. ZXUR 9000 GSM also supports
the five rates for AMR-HR speech coding7.4 kbit/s, 6.7 kbit/s, 5.9 kbit/s, 5.15
kbit/s, 4.75 kbit/s .
b. Circuit Switched Data Service at 9.6 kbit/s
c.
Short Message Services (SMS) (supporting messages in Chinese)
l MS terminated point-to-point short message service
l MS initiated point-to-point short message service
l Cell broadcast service originated from the SMC or the Operation and
Maintenance System
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d. GPRS Service
Supports point-to-point interactive telecom service, such as database access,
session service and tele-action service.
e. EDGE Service
4. Supports frequency hopping.
5. Supports discontinuous transmission (DTX) and voice activation detection (VAD).
6. Supports various handover modes.
Supports
synchronous
handover,
pseudo-synchronous handover.
non-synchronous
handover
and
Supports handover within frequency bands of 900 MHz, 1800 MHz, and between
900 MHz and 1800 MHz; it can process handover measurement; supports handover
measurement before handover; supports network initiated handover due to service or
interference management; supports handover between channels of different speech
coding rates; supports handover for DTX; supports handover caused by traffic
reasons; supports cocentric circle handover based on the carrier-to-interference ratio.
7. Supports 6-level static and 15-level dynamic power control for the MS and the BTS,
and supports fast power control based on the receiving quality.
8. Supports overload control and traffic control.
ZXUR 9000 GSM can locate and analyze system overload and report the cause to the
OMC. When the traffic is heavy, it can control the traffic through the A interface, the
Abis interface and the Gb interface by limiting some services, thus keeping the normal
system running while ensuring maximum call traffic capacity.
9. Supports call re-establishment upon radio link faults.
10. ZXUR 9000 GSM supports call queuing and forced call release in the provisioning and
handover programs.
11. Supports Enhanced Multi-level Precedence and Preemption (EMLPP).
The EMLPP classifies mobile subscribers into different priority levels. The subscribers
with higher levels are prioritized over others in obtaining channel resources.
12. Supports Co-BCCH.
Co-BCCH is used in dual-band cells. A dual-band cell is a cell that supports two
frequency bands that share the same BCCH.
Co-BCCH has the following advantages:
l
l
Saves a BCCH timeslot.
For the configuration of 1800M frequency in the 900M cell, it is unnecessary to
modify the existing adjacent cells and re-plan the network. The re-selection and
handover is also not required between dual-band cells that share the same site.
13. Supports dynamic HR channel conversion.
ZXUR 9000 GSM supports dynamic HR channel conversion. The system can
dynamically and automatically switch between HR and FR channels in real time
according to the call traffic.
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14. Supports dynamic radio channel assignment.
ZXUR 9000 GSM supports the dynamic assignment of CS and PS channels.
Dynamic channel assignment means that the logic type of radio channels can be
dynamically generated according to the current call type, instead of being configured
at the OMM (OMC client). The dynamic radio channel assignment makes it possible
to make the most of radio resources according to the service type.
ZXUR 9000 GSM performs channel allocation according to integrated analysis of
the channel rate, carrier priority, interference band, channel allocation on intra-cell
handover, allocation of reserved channels, and sub-cell channel selection.
15. Supports voice version selection.
ZXUR 9000 GSM supports voice version selection, which enables the user to set a
preferred voice version for FR and HR channels. The FR voice versions include FR,
EFR and AMR. The HR voice versions include HR and AMR.
16. Supports three-digit network IDs.
ZXUR 9000 GSM supports three-digit network IDs. Two-digit or three-digit network IDs
can be used according to the current network conditions. Based on the network ID,
the MNC in the signaling messages received over the A interface and the Gb interface
can be interpreted, thus determining the MNC format in the signaling messages to be
sent. The network ID is also the basis for determining the MNC format in broadcast
messages over the Um interface.
17. Supports handover between 2G and 3G systems.
l Supports the 3G-to-2G incoming handover for CS services.
l Supports the 2G-to-3G outgoing handover for CS services.
18. Supports full dynamic Abis.
Full dynamic Abis means the relation between radio channels and Abis channels is
not generated in the O&M system, but dynamically configured in the service process.
Dynamic Abis provides wider bandwidths for data services when the transmission
bandwidth over Abis is fixed.
19. Supports coding control.
Compared with GPRS, EDGE has significantly improved measurement reports. EDGE
measurement could be performed by pulses, that is, by the granularity of BURST.
The feature of rapid EGPRS measurement enables the network side to respond timely
to changes in radio environment, that is, choosing the most proper coding mode and
performing power control.
In the downlink direction, BSC supports the determination of coding modes by
timeslots and by TBF.
In the uplink direction, BSC determines the uplink TFB coding mode based on the
uplink channel measurement parameters reported by the BTS.
20. Supports retransmission.
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In the packet services, retransmission is controlled by negative feedback. The TX
side determines which packets are not correctly received by the RX side according
to the bitmaps sent from the RX side, thus deciding whether the network side should
retransmit the corresponding packets.
In GPRS, packet data is retransmitted using the same coding mode as the first
transmission. For example, if the packet data was originally transmitted using CS4
coding, it will be retransmitted with CS4 code.
EDGE introduces two new retransmission methods: Segmentation and Assembly
(SAR) and incremental redundancy.
21. Optimizes the algorithm for packet channel allocation.
ZXUR 9000 GSM supports the multi-timeslot function of MSs, and assigns GPRS TBF
or EDGE TBF to MSs according to their capacity of supporting GPRS or EDGE.
ZXUR 9000 GSM chooses low-load carriers first when assigning PDTCHs to the MSs.
After the carrier is selected, it chooses the most suitable PDTCH combination in the
carrier according to MS requirements.
22. Supports QoS.
When the GSM network evolves to GERAN, the high-speed transmission of packet
data brought by EDGE enables operators to provide subscribers with lots of colorful
new services, such as session service, stream media service, and interaction service.
ZXUR 9000 GSM supports different QoS requirements for these services.
23. Supports extended uplink Temporary Block Flow (TBF).
Before extended uplink dynamic allocation is introduced into the GPRS, the number of
uplink channels available for the uplink TBF is always less than or equal to the number
of downlink channels occupied by at the same time. However, ZXUR 9000 GSM
supports extended uplink TBF, which can realize more uplink channels than downlink
channels, thus better meeting the actual service needs.
24. Supports intelligent power-off.
When the performance data reaches the power-on/power-off threshold, ZXUR 9000
GSM notifies the BTS to perform power-on/power-off operations through a message.
ZXUR 9000 GSM can combine multiple scattered timeslots to allocate them to the
minimum number of carriers possible, and then shut down the unused carriers to
reduce power consumption. The scattered timeslots are preferentially combined onto
BCCH carriers.
ZXUR 9000 GSM supports the customization of intelligent shutdown by period to
prevent the intelligent shutdown from influencing the network in busy hours.
25. Supports TFO.
Tandem Free Operation (TFO) is an in-band codec negotiation protocol that makes
codec negotiation between two Transcoders (TC) after a call is set up. It eliminates
unnecessary voice code conversion at the sending and receiving ends of calls between
mobile subscribers, thus increasing voice quality and reducing transmission delay.
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26. Supports transparent channel.
The transparent channel implements transparent transfer of data between a timeslot
in the E1 line of an interface at one end and another timeslot in the E1 line of another
interface at the other end.
ZXUR 9000 GSM supports transparent channels from the Abis interface to the A
interface, from the Abis interface to the Abis interface, and from the A interface to
the A interface. When remote TC is implemented, transparent channel from the Abis
interface to the Ater interface is supported.
27. Supports EGPRS and GPRS channel scheduling.
Take GPRS mobile phone as an example. First, GPRS preferential channels are
assigned to the phone. When EGPRS channels are free and GPRS channels is heavily
loadded, EGPRS channels can be assigned to the phone. Contrarily, when EGPRS
channels have a heavy load and GPRS channels are free, GPRS phones can switch
to GPRS channels.
28. Supports the Dual-Transmission Mode (DTM).
ZXUR 9000 GSM supports DTM. Under A/Gb mode, ZXUR 9000 GSM can process
CS and PS services at the same time.
29. Supports subscriber signaling tracing.
ZXUR 9000 GSM implements subscriber signaling tracing based on IMSI, TMSI or
TLLI.
30. Supports PS paging coordination.
ZXUR 9000 GSM supports PS paging coordination. In packet transmission mode,
ZXUR 9000 GSM enables the MSs to intercept circuit paging messages.
31. Supports FLEX A.
When FLEX A is used, a BSC can connect to multiple MSCs, which constitute an MSC
POOL.
FLEX A provides flexible networking. Compared with the traditional single-MSC
structure, the MSC pool has the following advantages:
l
l
l
Expands the service area of one MSC, and reduces the frequency and traffic of
inter-MSC handover, location area update, and HLR update.
Improves the efficiency of network equipment. In one MSC Pool, the homing
VLR/MSC can be fixed. In this way, the load of an MSC does not increase when
the traffic in hot spot goes up in a short time.
Improves the overall disaster recovery capability of the network. When a MSC in
the MSC Pool is faulty, its traffic can be taken over by another MSC in the MSC
Pool.
The networking method of FLEX A is transparent to the MS, which means that the MS
is not involved when networking changes. This guarantees the compatibility of MS in
the network.
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32. Supports FLEX Gb.
FLEX Gb means one BSC can connect multiple SGSNs that form SGSN pools.
FLEX Gb provides flexible networking modes. Compared with the traditional
single-SGSN structure, the SGSN pool provides the following advantages:
l
l
l
Expands the service area of one SGSN, and reduces the frequency and traffic of
inter-SGSN PS handover, routing area update and HLR update.
Improves the efficiency of network equipment. In an SGSN POOL, the homing
VLR/SGSN can be fixed. In this way, the load of an SGSN does not increase
when the traffic of a hot spot goes up suddenly.
Improves the overall disaster recovery capability of the network. When a SGSN
in the SGSN Pool is faulty, its traffic can be taken over by another SGSN in the
SGSN Pool.
For MS, the networking mode of FLEX Gb is transparent, that is, the MS is not involved
in the modification of networking mode. This guarantees the network compatibility with
the MS.
33. Supports preemption and queuing for packet services.
The preemption of packet services considers all dynamic and static packet channels
in assigning packet radio resources according to subscriber QoS requirements. If the
free radio resources on a channel cannot meet QoS requirements or the maximum
number of subscribers is reached in the channel, and the current subscriber has the
right of preemption, the BSC will attempt to forcibly release the radio resources of one
or more low-priority subscribers for the use of the current subscriber.
When the BSC cannot allocate sufficient packet radio resources according to
subscriber QoS requirements, the queuing of packet services allows the BSC to admit
services as many as possible, and then queue them up to wait for radio resources
that meet subscriber QoS requirements.
When the BSC supports both preemption and queuing, the preemption of packet
services precedes queuing in priority. Queuing is activated when preemption fails.
34. Supports re-selection of the external network assisted cell.
re-selection of assisted cell in external network accelerates the access speed of the MS
during re-selection of an external cell, shortens the cell re-selection time during data
transmission, increases data transmission rate, thus providing better user experience.
35. Supports network controlled cell re-selection.
Network controlled cell re-selection is a procedure in which the BSC receives the
measurement report from the MS, and then performs storage and weighted average
processing of the measured level values of the service cell and the adjacent cells. The
calculation result is analyzed together with network service load conditions to make
cell re-selection decisions.
By fully utilizing available information and making reasonable decisions, the network
controlled cell re-selection optimizes network services. The function also reduces
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MS autonomous re-selection of useless cells, thus increasing TBF data transmission
efficiency and providing the best service quality to end users.
36. Supports uplink incremental redundancy.
Incremental redundancy is a method to control the link quality for EDGE. With this
method, when the BTS successfully decodes the RLC head but fails to decode a
data chunk, the BTS stores this data chunk and informs the MS. The MS then uses
another perforation method to encode and retransmit the data chunk so that the BTS
can decode the resent data chunk. If decoding fails, the stored data chunk on BTS can
be used together to perform joint decoding. Data chunks using different perforation
methods have different redundant information. Therefore, joint decoding has a higher
success rate because more redundancy information can be utilized.
37. Supports Multiple PLMN IDs.
ZXUR 9000 GSM supports the radio network sharing among different operators.
Operators can configure their own cells on the same site to provide common access
for subscribers with different operators.
38. Supports noise suppression (only for E1 A interface) and level control.
Noise suppression can increase the voice SNR, enhance voice quality, and provide a
more comfortable communication environment.
Level control helps to optimize signal levels, thus improving communication quality.
TFO is exclusive with noise suppression and level control. If the TFO is established,
noise suppression and level control are not necessary.
39. Supports higher-order multiple timeslots for PS services.
ZXUR 9000 GSM supports higher-order multiple timeslots for PS services. The
downlink can have up to five timeslots at the same time, which increases the downlink
rate to 296 Kbps. The increased transmission rate can significantly improve user
experience for FTP transmission and email services.
40. Supports IP transmission for the A interface.
With the evolution of network technology, it is easier to get IP-based transmission
resources. Compared with the traditional circuit network, IP network has a higher
utilization rate and more flexible networking modes.
ZXUR 9000 GSM supports IP-based bearing at the A interface, which helps the
network evolve to an all-IP network. With this feature, the GSM can be easily
integrated with the transmission network in the future.
2.1.2 Mobility Management
ZXUR 9000 GSM provides the following mobility management functions:
l
Cell Reselection
Supports inter-BSC and intra-BSC cell reselection.
l
Cell Handover
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Supports inter-BSC and intra-BSC cell handover.
2.1.3 Channel Management
ZXUR 9000 GSM supports the following channel management functions:
1. Service channel management
l channel assignment
l link monitoring
l channel release
l channel blocking/unblocking
l channel conversion
l function control
2. Supported Control Channels
l FCCH
l SCH
l BCCH
l PCH
l AGCH
l RACH
l SDCCH
l SACCH
l FACCH
l PACCH
l PAGCH
l PBCCH
l PCCCH
l PPCH
l PRACH
l PTCCH
2.1.4 External Interface
ZXUR 9000 GSM supports the following external interfaces:
l
Abis Interface
The interface connects the BSC with the BTS. To connect the BTS for configuration
and management, the BSC provides the E1/T1 interface, CSTM-1 interface, Ethernet
FE(electrical port)/GE(optical or electrical port) interface.
l
A Interface
The interface connects the BSC with the CN, that is, MSC/MGW. To connect the
CN, the BSC provides the E1/T1 interface, CSTM-1 interface, Ethernet FE(electrical
port)/GE(optical or electrical port) interface.
l
Gb Interface
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The interface connects the BSC with the SGSN. To connect to the SGSN, the BSC
provides the E1/T1 interface, CSTM-1 interface, Ethernet FE(electrical)/GE(optical or
electric) interface.
l
OMC Interface
Operations can be performed on the OMC client to control and maintain the BSC and
the BTS.
2.1.5 Radio Resource Management
The BSC provides the following radio resource management functions:
l System Access Control
System access of a subscriber is initiated at the subscriber side (e.g., mobile caller) or
the network side (e.g., mobile called party). The access of a subscriber is to acquire
GSM services through GERAN. GERAN controls the access according to subscriber
capability and resources utilization.
l
Access Control
The system decides whether to accept user's access request based on such aspects
as current resource utilization, load level, general interference level of the cell, total
transmission power, and the bandwidth resource of the Abis interface.
l
Load Control
When multiple subscribers access to the system, the BSC monitors the system load,
determine whether the system is overloaded and, if yes, the overload level. After that,
the BSC takes measures according to preset rules to ensure system stability.
l
Power Control
Given that the signal quality is ensured, the transmit power is kept at a low level to
improve system capacity.
In the uplink, open loop and closed loop power control are adopted. When the
uplink is not established, the open loop power control regulates the transmit power
in the Physical Random Access Channel (PRACH). Closed loop power control is
used after the link is established. Closed loop power control includes outer loop and
inner loop power control. Outer loop power control adjusts the bit error rate (BER)
or frame error rate (FER), while inner loop power control targets adjusts the target
signal-to-interference rate (SIR).
In the downlink, only closed loop power control is used.
l
System Message Broadcast
This function broadcasts the information of the access layer and non-access layer to
the MS for access to the GSM services.
l
Radio Environment Measurement
This function measures the present public channels and dedicated channels
according to radio resource management requirements.
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l
Dynamic Channel Allocation
Dynamic channel allocation includes low-speed channel allocation and high-speed
channel allocation. High-speed channel allocation conforms to the principles specified
in access control. Low-speed channel allocation allocates radio resources to different
cells according to their service load.
2.1.6 Network Management Functionality
l
Configuration Management
Configuration of BSC physical and logical resource, radio parameter configuration,
data import/export.
l
Security Management
Network security control and operation log management.
l
Fault Management
Displays and saves alarm data that reflects equipment faults and threshold-crossing
cases.
l
Signaling Tracing
Tracing signaling according to specified BTSs, cells, and MSs for fault analysis.
l
Performance Statistics
Performs statistics on services and data transmission.
l
Diagnosis Testing
Diagnoses system faults.
2.2 Technical Specifications
2.2.1 Physical Specifications
l
l
Dimensions
à
Cabinet size: 2200 mm×600 mm×800 mm (height×width×depth)
à
Cabinet color: dark blue
à
Cabinet structure: three-layer subracks, with 14 slots on both front panel and
backplane
Cabinet Weight
Maximum weight of a single cabinet: 430 kg
2.2.2 Power Specifications
The power specifications of ZXUR 9000 GSM are shown in Table 2-1.
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Table 2-1 Power Specifications
Parameter
Specification
Power supply
-48 V DC
Allowed power range
-40 V DC to -57 V DC
Maximum power consumption
9000 W
2.2.3 Backup Configuration
As a measure to improve reliability, ZXUR 9000 GSM provides backup protection for major
boards.
l
l
l
l
l
1+1 backup for interface boards.
Load sharing for switch boards.
1+1 backup for control plane processing boards.
Load sharing for user plane processing boards.
The interface boards using the optical fiber and peer-end connection are protected
by inter-board APS to ensure the reliability of high-speed lines, particularly optical
interface transmission.
2.2.4 Environment Requirements
2.2.4.1 Grounding Requirement
ZXUR 9000 GSM includes the -48V ground, work ground and protection ground.
l
l
l
The -48V and -48 VRTN three-channel power supplies enter the cabinet from the top.
The -48 VRTN and GND converges outside the cabinet. The protection earth (PE)
connects to the earth.
The rack provides both top grounding and bottom grounding.
Rack bonding resistance ranges from 0.1 to 0.3 ohms, while the ground resistance
should be less than 1 ohm in the equipment room.
2.2.4.2 Temperature and Humidity Requirements
l
Temperature and humidity range for stable operation:
à
Temperature range
Long-term operation: 0 ℃ to 45 ℃
Short-term operation: -5 ℃ to 50 ℃
à
Humidity range
Long-term operation: 5 % to 85 %
Short-term operation: 5 % to 90 %
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Note:
The short-term operation means that the continuous operating period does not exceed
96 hours and the accumulative total period within a year does not exceed 15 days.
2.2.4.3 Cleanliness Requirements
The equipment room must meet the following cleanliness requirements:
l
l
l
l
l
l
No explosive, conductive, magnetic or corrosive dust.
The thickness of dust particles with larger than 5 um in diameter should be less than
or equal to 3*104 particles/m3.
No corrosive metals or gases that are harmful to insulation.
The equipment room has the capacity to shield some outside electromagnetic
interference.
The rack should be with earthquake-resistance consolidation.
It is permitted that the storage and transportation are with no air-conditioning.
When some of the above requirements cannot be met, the basic requirement is that the
equipment room environment resembles the general indoor conditions of different regions
in China.
2.2.4.4 Atmospheric Pressure Requirements
The atmospheric pressure range for storage: 70 kPa to 106 kPa
The atmospheric pressure range for normal operation: 86 kPa to 106 kPa
2.2.4.5 Electro-Magnetic Compatibility
ZXUR 9000 GSM is resistant to electromagnetic interference, conforming to
requirements specified in GB/T17618-1998 Information technology equipment–Immunity
characteristics–Limits and methods of measurement.
ZXUR 9000 GSMThe self-produced electromagnetic interference of the product conforms
to requirements of GB9254-1998.
ZXUR 9000 GSMThe EMC specifications of the product conforms to requirements
specified in EN 300 386 V1.4.1:2008EN 60950–1/A11:2009.
The product has passed the FCC Part 15 certification.
The product has passed the UL certification.
2.2.4.6 Transportation Requirements
The storage conforms to requirements of GB/T 4798.1. The storage duration should be
less than 12 months. Otherwise, the equipment should be tested before operation.
l
Temperature requirement for storage: -40 ℃ to +60 ℃
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l
Humidity requirement for storage: 10 % to 95 %
With regular packing, the product can endure the shaking and bumping.
2.2.5 Security Specifications
l
Optical protection
The optical interface conforms to the requirements of BS EN 60825-2-2000.
l
Rack stability
The general symmetry ensures that the rack will not fall down at a tilt table of at least
10 degrees. The outer cases of the cabinet and subracks are fixed and can endure
general hit.
l
Rack security protection
Security protection level should be IP20.
l
Electrical leakage
The leak electrical current of this product is less than or equal to 3.5 mA.
l
Safety signs
The product has clear enduring safety signs. All indicators, switches, or buttons of the
equipment have clear application meanings for different colors.
l
Heat resistance and fireproofing
The outer case of the produce is heat-resistant and fireproofing.
l
Earthquake resistance
The equipment is safe against 8 magnitude earthquakes.
2.2.6 Interface Specifications
The interface boards of ZXUR 9000 GSM are all rear boards. Up to 30 slots are provided
for rear boards. The maximum numbers of supported ports for one slot are listed in Table
2-2.
Table 2-2 Maximum Supported Interface Number of One Slot
Interface Type
Maximum Number of Ports
CSTM-1
4
E1/T1
32
FE/GE
4
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2.2.7 Capacity Specifications
The typical single rack configuration involves the following capacity specifications, as
shown in Table 2-3.
Table 2-3 Capacity Specifications
Parameter
Specification (TDM A interface with
Specification (IP A interface)
built-in TC)
Number of racks
1
1
Number of TRX
5600
12250
Number of
2800
6125
Erl
33600
73500
BHCA(K)
8400
16800
Maximum Data
19600 MCS9 PDCH
42875 MCS9 PDCH
Sites/Cells
Throughput
(Number of
Channels)
2.2.8 Clock Specifications
l
l
l
l
l
l
l
l
Clock level: Level 3 Class A
Minimum clock accuracy: ±4.6×10-6
Pull-in range: ±4.6×10-6
Maximum frequency deviation: 2×10 -8 Hz/Day
Maximum initial frequency deviation: 1×10-8 Hz
Clock working mode: Capture, trace, keep, free
Clock synchronization mode: External clock synchronization, or extracting from the
circuit clock
Clock synchronization interface: 2MBITS(2 MHz, 2 Mbps), GPS, Line Clock
Reference (E1/T1, CSTM-1, Synchronous Ethernet), 1588 V2
2.2.9 Reliability Specifications
ZXUR 9000 GSM has the following reliability specifications shown in Table 2-4.
Table 2-4 Reliability Specifications
Item
Specification
MTBF
More than 650000 hours
MTTR
30 minutes
Availability
99.99992 %
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Item
Specification
System downtime
Less than 1 minutes per year for whole system
downtime
Redundancy configuration
Board 1+1 backup or load sharing
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Chapter 3
Product Structure
Table of Contents
Logic Structure ...........................................................................................................3-1
Hardware ...................................................................................................................3-3
Software.....................................................................................................................3-9
3.1 Logic Structure
3.1.1 System Logical Structure
ZXUR 9000 GSM has the following logical structure, as shown in Figure 3-1.
Figure 3-1 Logical Structure
•
•
BTS: Base Transceiver
Station
MSC: Mobile Switching
Center
•
•
•
SGSN: Service GPRS
Supporting Node
AU: Access Unit
SU: Switching Unit
•
•
O & M Unit: Operation and
Maintenance Unit
PMU: Peripheral Monitoring
Unit
3.1.2 System Logical Units
ZXUR 9000 GSM involves five logical units with different functions. The functions of the
five units and the boards involved are illustrated in Table 3-1.
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Table 3-1 Five Logical Units
Logical Unit
Function
Boards Involved
Operation and Maintenance
The unit handles the global
UMP, ECDM
Unit
process and the O&M control
at system-level. It also isolates
internal and external network
segments and provides the
global clock.
Access Unit
This unit concerns external
EDTT, ESDTT, ESDTG, ESDTI,
interfaces, including Abis, A,
EDTI, EGPB
and Gb (E1/T1, CSTM-1, IP). It
implements part of the link layer
processing.
Processing Unit
This unit processes the radio
USP, ETCB
control-plane and user-plane
protocols and part of the data
bearer protocols related to
transmission.
Switching Unit
This unit performs intra-shelf
EGBS, EGFS
and inter-shelf Layer-2
switching, providing user-plane
and control-plane as switching
planes.
Peripheral Monitoring Unit
This unit belongs to O&M
PDUM, PDUB, PDUC, EPCB,
module and is responsible
EFMB, NFCM, NFSD, ALB
for collecting peripheral
information and environment
board information within the
cabinet, including the status
of power distributor and fan,
the environment alarms that
reflect changes in temperature,
humidity, smog, water, and
infrared. The unit raises
system alarms of different
levels according to system
fault grades, thus facilitating
timely handling by equipment
management personnel.
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3.2 Hardware
3.2.1 Cabinet Structure
The cabinet is made up of the following components:
l Cabinet door and rack
l
à
Four doors: Front/rear doors and left-right doors
à
Rack: supports the whole cabinet.
Subracks
à
Power Distribution Unit (PDU) (3 U): Located at the top of the cabinet, the PDU
provides power to subracks. The unit can automatically switch between two
3-channel outer power sources, with power indicator and environment monitor
functions.
à
ETCA subrack (11 U): The cabinet can admit up to three such subracks.
à
Ventilation subrack (5 U): Shared space between subracks. Independent of other
subracks, this subrack changes the air duct from a vertical one to a horizontal one.
l Wind trap component (2 U): traps and converges wind.
l Ventilation panel: Dust-proof decoration. One or two such panels for a cabinet.
The cabinet structure of ZXUR 9000 GSM is shown in Figure 3-2.
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Figure 3-2 Cabinet Structure
1.
2.
3.
4.
5.
Front door
Side door 1
Rear door
Side door 2
Rack
6.
7.
8.
9.
10.
Power distribution unitPDU
Ventilation panel1 U
ETCA subrack11 U
Wind trap component2 U
ETCA subrack11 U
11. Ventilation subrack5 U
12. ETCA subrack11 U
13. Ventilation panel3 U
3.2.2 Subrack Structure
The ETCA subrack includes
l Fan unit: Two fan units are located at the front of the cabinet, while one fan unit at the
back.
l Service subrack: one subrack component on the front, one on the back of the cabinet,
separated by the backplane.
l Power supply unit (Power Distribution Box): two PDUs at the back of the subrack,
supporting four power inputs.
l Enhanced Chassis Data Module (ECDA): two modules located on the back of the
subrack, used to manage subrack slots information.
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The ETCA subrack structure is illustrated in Figure 3-3 and Figure 3-4.
Figure 3-3 ETCA Subrack - Front View
1. Fan unit 1
2. Fan unit 2
3. Service subrack
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Figure 3-4 ETCA Subrack - Rear View
1. Fan unit
2. Service subrack
3. Power supply unit 1
4. Power supply unit 2
5. ECDM 1
6. ECDM 2
3.2.3 Front Boards
The front boards of ZXUR 9000 GSM processes services, as illustrated in Table 3-2.
Table 3-2 Front Board Functions
Function
Physical
Board
Board
UMP
SBCJ
Function
OMM: operation and maintenance of NEs. provides the GE interface
for connecting the EMS.
OMP: Processes the global process and controls the operation and
maintenance of the whole system. It connects the OMM through
the internal media plane. As the processing core of operation and
maintenance, the OMP board directly or indirectly monitors and
manages all boards in the system. It provides an Ethernet interface for
the configuration management of boards and other components.
USP
SBCJ
CMP: Protocol processing on the control plane at the interfaces Abis,
A, and Gb.
RUP: Protocol processing on the user plane.
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Function
Physical
Board
Board
ETCB
ETCB
Function
When the A interface adopts TDM, TC processing is implemented.
The interfaces of boards are illustrated in Table 3-3.
Table 3-3 Board Interfaces
Function
Interface
Remarks
2×1G, connects 2 EGBS boards on the back plane,
1+1 backup
Board
UMP
control plane
2×1G, connects 2 EGFS boards on the back plane,
media plane
USP
2×1G, connects 2 EGBS boards on the back plane,
CMP: 1+1 backup
control plane
RUP: load sharing
2×1G, connects 2 EGFS boards on the back plane,
media plane
ETCB
2×1G, connects 2 EGBS boards on the back plane,
load sharing
control plane
2×1G, connects 2 EGFS boards on the back plane,
media plane
3.2.4 Rear Boards
ZXUR 9000 GSM is configured with the boards illustrated in Table 3-4.
Table 3-4 Rear Boards
Board
Function
Interface
Remarks
EDTT
TDM Over E1/T1 at the
2×1G, the back plane connects 2
No backup or 1+1
EGBS boards, control plane
backup
interfaces A, Abis, and Ater
4×1G, the back plane connects 2
EGFS boards, media plane
32×E1/T1
EDTI
IP Over E1/T1 at the
2×1G, the back plane connects 2
No backup or 1+1
backup
interface Abis
EGBS boards, control plane
TDM Over E1/T1 at the
4×1G, the back plane connects 2
interface Gb
EGFS boards, media plane
32×E1/T1
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Board
Function
Interface
Remarks
EGPB
IP processing at the
2×1G, the back plane connects 2
Load sharing
GE interface (optical or
EGBS boards, control plane
1+1 backup
electrical)
4×1G, the back plane connects 2
EGFS boards, media plane
4×1G, external single-mode
ESDTT
TDM Over CSTM–1 at the
2×1G, the back plane connects 2
interface A
EGBS boards, control plane
1+1 backup
4×1G, the back plane connects 2
EGFS boards, media plane
ESDTI
ESDTG
IP Over CSTM-1 at the
2×1G, the back plane connects 2
interfaces Abis
EGBS boards, control plane
TDM Over CSTM-1 at the
4×1G, the back plane connects 2
interface Gb
EGFS boards, media plane
TDM Over CSTM-1 at the
2×1G, the back plane connects 2
interfaces Abis and Ater
EGBS boards, control plane
1+1 backup
1+1 backup
4×1G, the back plane connects 2
EGFS boards, media plane
EGBS
Control plane switching of
Switching:
the service subrack
l
1+1 backup
26×1G, the back plane
Management functions of
connects 24 service slots
the system subrack
and the EGFS board, control
plane
l
4×1G, inter-subrack
connection at the control
plane
l
2×10G, peer boards stack
l
1×GE, connecting to the
CMM of the peer board
l
1×GE, connecting to the
clock module of the peer
board
CMM:
l
1×FE, connecting to the
CMM of the peer board
l
1×FE, connecting to the peer
board HUB
l
27×I2C, connecting 26
service slots, the power
supply, fan, and the peer
board
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Board
Function
Interface
Remarks
EGFS
Media plane switching
Media plane switching:
1+1 backup
Clock
l
34×1G, the back plane
connects 24 service slots,
14 front interfaces, 20 rear
interfaces, media plane
l
2×1G, connecting to the
control plane of EGBS
l
2×10G, inter-subrack
connection at the media
plane
l
2×10G, active-standby
interconnection
Clock
l
1× antenna port, connecting
to the GPS antenna via cable
l
2× clock input, connecting to
the BITS reference via cable
l
3× clock output, connecting
to other subracks
PDUM
Measuring the temperature
1×485, connecting to the UMP
and humidity
(OMP) via cable
One board per rack
Testing power supply
3.3 Software
3.3.1 NE Software and the EMS
The software architecture includes the NE software and operation and maintenance
module (OMM) client (or OMC).
1. NE Software
The software runs on the cabinet of ZXUR 9000 GSM, responsible for service
processing.
2. OMM Client
This software is the client of the operation and maintenance module. The client
provides functions to manage the NEs of the BSS, such as fault management,
performance management, and configuration management.
The communication between the ZXUR 9000 GSM equipment and the OMM client
conforms to the TCP/IP protocol.
The software architecture of ZXUR 9000 GSM is shown in Figure 3-5.
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Figure 3-5 Software Architecture
3.3.2 Classification of NE Software
The system software can be divided into two categories.
l
Version Software
Version software can be managed on the EMS client. It that can be dynamically
updated.
l
Firmware
Firmware is a software program written on the hardware chips and cannot be updated
on the EMS client.
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Chapter 4
Networking
Table of Contents
Networking via the Abis Interface ...............................................................................4-1
Networking via the A/Gb Interface ..............................................................................4-3
4.1 Networking via the Abis Interface
ZXUR 9000 GSM supports several ways of networking.
According to the network topology, ZXUR 9000 GSM supports the star networking,
chain networking, ring networking (requires supported transmission network), and hybrid
networking.
The Abis interface supports following transmission modes: CSTM-1, E1/T1, Ethernet
GE/FE (optical or electrical).
4.1.1 Star Networking
The star networking involving ZXUR 9000 GSM is shown in Figure 4-1.
Figure 4-1 Star Networking
In star networking, ZXUR 9000 GSM connects with BTS directly. This networking is
simple, and the maintenance and engineering are very convenient too. Since the signals
are transmitted through fewer intermediate links, the reliability of transmission is higher.
Generally, this networking is adopted in densely-populated urban areas.
4.1.2 Chain Networking
The chain networking involving ZXUR 9000 GSM is shown in Figure 4-2.
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Figure 4-2 Chain Networking
Chain Networking has relatively more intermediate links, so that the reliability is poorer.
Chain networking is usually applied in strip-shaped areas with sparse population, and a
large amount of transmission equipment can be saved.
The chain networking can also be applied in the case of one site having multiple BTSs.
In actual engineering networking, the transmission equipment is generally added between
ZXUR 9000 GSM and BTSs, different from the basic networking, because the sites are
often scattered. The common transmission media include: microwave, fiber cable, HDSL
cable, and coaxial cable.
4.1.3 Ring Networking
The ring networking involving ZXUR 9000 GSM is shown in Figure 4-3.
Figure 4-3 Ring Networking
The ring networking involves two sets of links running in the active/standby relation. Every
node on the ring has two upper-level nodes, thus improving the link reliability. Therefore,
if a site is damaged or a link fails, the subordinate nodes can select another link as the
active one.
4.1.4 Star-Chain Hybrid Networking
The star-chain hybrid networking involving ZXUR 9000 GSM is shown in Figure 4-4.
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Figure 4-4 Star-Chain Hybrid Networking
The advantages of hybrid networking are:
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Easily adaptable to the current transmission mode of the operator. In early
establishment of the network, hybrid networking makes the most of the established
transmission network, thus saving the network cost and speeding the network
establishment for the operator.
Easier networking on complex terrain. Hybrid networking supports multiple topology,
thus making network establishment flexible and simple.
Easy configuration of abundant transmission paths, thus enhancing the network
robustness.
4.2 Networking via the A/Gb Interface
The A interface connects the BSC with the MSC/MGW.
The Gb interface connects the BSC with the SGSN.
4.2.1 Networking via the Gb Interface
The networking via the Gb interface is shown in Figure 4-5.
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Figure 4-5 Networking via the Gb Interface
The Gb interface supports following transmission modes: CSTM-1, E1/T1, and Ethernet
GE/FE (optical or electrical ports).
4.2.2 Networking via the A Interface
The networking with the A interface is shown in Figure 4-6.
Figure 4-6 Networking via the A Interface
The A interface supports following transmission modes: CSTM-1, E1/T1, and Ethernet
GE/FE (optical or electrical ports).
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Chapter 5
System Configuration
Table of Contents
Configuration Description ...........................................................................................5-1
Board Configuration ...................................................................................................5-2
Subrack Configuration ................................................................................................5-3
Cabling Configuration.................................................................................................5-5
Configuration of Network Management Software........................................................5-6
5.1 Configuration Description
ZXUR 9000 GSM has three typical application scenarios: single subrack, double subracks,
and tri-subrack configuration.
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Single subrack
This configuration means that the BSC is configured with one service subrack.
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Double subracks
The BSC is configured with two service subracks.
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Triple subracks
The BSC is configured with three subracks.
The hardware of this product can be divided into interface resources, system processing
resources, and switching resources.
The general system configuration is related to these resources.
Refer to the following list for the configuration:
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Interface board: EGPB, EDTT, ESDTT, ESDTG, EDTI, ESDTI
Control boards: UMP (OMM, OMP)
Processing boards: USP (CMP, RUP), ETCB
Switching boards: EGBS, EGFS
The traffic model contains the following indexes:
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The number of sites/cells
Traffic volume
Equivalent BHCA
The number of PDCH
The system performance indexes can be calculated from the assuming parameters of the
traffic model and necessary input parameters (for example, the number of cells and the
number of interfaces). The number of important boards can thus be obtained.
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The number of interface boards is dependent on total traffic of each interface and the
number of external equipment.
The processing resources on the user plane are the key factor for system configuration.
The requirement of processing resources on the user plane can be obtained by collecting
total system voice traffic and the user-plane board traffic. And then the control-plane
processing resources can be calculated by data matching based on the user-plane data.
The required amount of system control resources and switch platform resources can be
calculated from the amount of the above resources.
5.2 Board Configuration
The configuration of front boards is illustrated in Table 5-1.
Table 5-1 Board Configuration List
Board
Number of Boards for
Number of Boards for
Number of Boards for
Single Subrack
Double Subracks
Triple Subracks
UMP (OMM)
2
2
2
UMP (OMP)
2
2
2
USP (CMP)
Depending on the
Depending on the
Depending on the
system requirement
system requirement
system requirement
and the processing
and the processing
and the processing
capacity of the board
capacity of the board
capacity of the board
USP(RUP)
ETCB
The configuration of rear boards for single-subrack, double-subrack, and triple-subrack
scenarios is illustrated in Table 5-2.
Table 5-2 Rear Board Configuration List
Board
Number of Boards for
Number of Boards for
Number of Boards for
Single Rack
Double Racks
Triple Racks
EGFS
2
4
6
EGBS
2
4
6
Interface board
Depending on the
Depending on the
Depending on the
processing capacity of
processing capacity of
processing capacity of
the interface and the
the interface and the
the interface and the
board, and the backup
board, and the backup
board, and the backup
configuration
configuration
configuration
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5.3 Subrack Configuration
5.3.1 Typical Configuration for Single Service Subrack
Figure 5-1 lists the typical board configuration for a single-subrack scenario. The type of
the interface board is decided by the actual networking.
Figure 5-1 Typical Configuration for Single Subrack
5.3.2 Typical Configuration for Double Service Subracks
In the double-subrack scenario, the two subracks are configured as master-subordinate
peers. Figure 5-2 lists the typical board configuration for a double-subrack scenario. The
type of the interface board is decided by the actual networking.
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Figure 5-2 Typical Configuration for Double Subracks
5.3.3 Typical Configuration for Triple Service Subracks
In the triple-subrack scenario, the three subracks are configured as one master, two
subordinate subracks. Figure 5-3 lists the typical board configuration for a triple-subrack
scenario. The type of the interface board is decided by the actual networking.
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Figure 5-3 Typical Configuration for Triple Subracks
5.4 Cabling Configuration
The cables inside the rack (single-subrack configuration does not include internal cables)
are configured as follows:
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The 10GE optical fiber connects the EGFS board in the master subrack with the same
board in the subordinate subrack on the media plane.
The Gigabyte Ethernet (GE) optical fiber connects the EGBS board in the master
subrack with the same board in the subordinate subrack on the control plane.
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The clock reference cable connects the clock output on the EFGS board in the master
subrack to the clock input on the EFGS board in the subordinate subrack.
The cabling outside the rack includes:
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The EGFS board in the master subrack is connected to the BITS clock reference via
cable.
The types of interface boards connect to the external network via the Ethernet cable,
optical fiber, or E1 cable.
5.5 Configuration of Network Management Software
The operation and maintenance (O & M) server is installed on the USP (OMM) board,
while the client is installed on the PC. The client PC requires the following configurations
illustrated in Table 5-3.
Table 5-3 OMM Client Configuration
Part
Suggested Configuration
CPU
2.4Gb, 8-core
Memory
12Gb or more
Hard Disk
SAS
CD-ROM Driver
Not equipped
Network Port
2*1Gb electrical port
Video adapter
Default video adapter
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Chapter 6
Signal Processing Flow
The signals in ZXUR 9000 GSM include the clock signal, signaling, the operation and
maintenance signal, and the user plane data. This chapter analyzes the signal processing
flows involved. As examples, the Abis interface adopts the IP port, the A interface adopts
the TDM over CSTM–1, the Gb interface adopts the IP port.
Table of Contents
Circuit-Switched User Plane Data ..............................................................................6-1
Packet-Switched User Plane Data .............................................................................6-2
Control Plane Signaling .............................................................................................6-2
BTS Operation and Maintenance Data .......................................................................6-3
6.1 Circuit-Switched User Plane Data
The CS data flow at the Abis interface starts from the interface board EGPB, and then
flows to the ETCB for transcoding (TC). After that, the data is sent to the A interface board
through the IP switching network on the user plane. Through the A interface on the ESDTT
board, the data undergoes the IP-to-TDM conversion, and is sent to the MGW.
The uplink CS data flow on the user plane is illustrated in Figure 6-1 as an example. The
downlink data flow goes in the opposite direction.
Figure 6-1 CS User Plane Data Flow
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6.2 Packet-Switched User Plane Data
The PS data at the Abis interface starts from the interface on the EGPB, and flows to the
RUP board for PS processing according to relevant protocols. After that, the data is sent
to the Gb interface on the EGPB before it is sent to the SGSN.
The uplink PS data flow on the user plane is illustrated in Figure 6-2 as an example. The
downlink data flow goes the opposite way.
Figure 6-2 PS User Plane Data Flow
6.3 Control Plane Signaling
Control Plane Signaling at the Abis Interface
The EGPB (Abis interface board) transmits the control plane protocol messages at the
Abis interface through the control plane switching network to CMP for protocol processing.
The uplink signaling flow at the Abis interface is illustrated in Figure 6-3 as an example. The
figure shows the signaling flow between the master subrack and the subordinate subrack.
The signaling in the downlink goes in the opposite direction.
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Figure 6-3 Signaling Flow at the Abis Interface
Control Plane Signaling at the A Interface
The MTP2 protocol at the A interface is processed on the ESDTT board, while the MTP3
and higher protocols are sent to be processed on the CMP via the Ethernet.
The downlink signaling flow at the A interface is illustrated in Figure 6-4 as an example. The
figure shows the signaling flow between the master subrack and the subordinate subrack.
The signaling flow in the uplink goes in the opposite direction.
Figure 6-4 Signaling Flow at the A Interface
6.4 BTS Operation and Maintenance Data
The operation and maintenance data of the BTS is sent from the Abis interface to the
interface board EGPB in the access unit for the physical layer processing. After that, the
data is sent to the EGPB in the master subrack via the switching unit, before it is sent to
the OMM board via the OMM VLAN of the EGPB.
The operation and maintenance data flow of the BTS is illustrated in Figure 6-5.
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Figure 6-5 Flow of the BTS Operation and Maintenance Data
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Chapter 7
Reliability
Table of Contents
Hardware Reliability Design........................................................................................7-1
Software Reliability Design .........................................................................................7-2
Heat Dissipation Design .............................................................................................7-3
7.1 Hardware Reliability Design
The rack and service subracks all adopt dual power supplies, so that at least
double-channel cables are used inside the rack. The control plane boards adopt the
active/standby working mode, while the user plane boards adopt the load sharing working
mode. The interface boards adopt either the active/standby or the load sharing working
mode. Therefore, the faults of any individual hardware do not affect the normal operation
of the system.
7.1.1 Types of Board Backup
The boards in ZXUR 9000 GSM adopt one of the three backup modes: No backup, 1+1
backup, and load sharing.
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No Backup
The board has no backup configuration.
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1+1 Backup
1+1 backup is also called the active/standby backup. Of the two boards as
active-standby peers, only the active board is in operation at a certain time.
If any fault occurs to the active board, the system switches the standby/active relation.
The standby board is switched as active, while the active board is switched as standby.
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Load Sharing
Load sharing backs up the service data on the board.
When a service is running, related services are distributed on multiple boards. If an
individual board fails, the service on the failed board can be shared by other boards
to ensure the full operation of the service.
7.1.2 Supported Backup Mode for Different Boards
At present, the boards equipped with ZXUR 9000 GSM have different backup modes, as
listed in Table 7-1.
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Table 7-1 Board Backup Mode Details
Function Board
Supported Backup Mode
Description
UMP(OMP/OMM)
1+1 backup
The OMP must adopt the 1+1
backup, because this board
performs centralized control
over the whole system.
ETCB
Load Sharing
-
EDTT
No backup, 1+1 backup
-
EDTI
No backup, 1+1 backup
-
ESDTT
1+1 backup
-
ESDTI
1+1 backup
-
ESDTG
1+1 backup
-
EGPB
Load sharing, 1+1 backup
-
EGBS
Load Sharing
Provides load sharing upon
occurrence of a fault
EGFS
Load Sharing
Provides load sharing upon
occurrence of a fault
USP (CMP)
1+1 backup
-
USP(RUP)
Load Sharing
-
Note:
The two boards as active-standby peers may not use two neighboring slots. The slot
distribution is decided by the cabling on the back plane.
7.2 Software Reliability Design
The system software adopts reliable design. All the system, except the external operation
and maintenance interfaces, has an internal communication network completely separated
from the outer network. Besides, the system is equipped with a built-in firewall to protect
the external O & M interfaces against attacks. At the same time, the O & M subsystem
supports high-security authentication design, which enables the authorization of different
levels of operations to users.
The product has powerful fault tolerance, which can be illustrated by the following aspects:
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Automatic testing for user-defined configurations. Illegal or improper configuration will
be rejected, and the user will be prompted to make proper settings.
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Supports the backup of the key version or major data as the basis for rollback in the
case of failed loading of a version or relevant data.
The Watchdog function can restart a board to resume operation when an error occurs
during the software operation. Meanwhile, the black box records the runtime errors
for further analysis.
During the backup of hardware, the software can automatically test the faults occurring
at ports, links, and other faults. If any fault is tested, the software automatically start
or activate the standby unit to ensure proper system operation.
7.3 Heat Dissipation Design
7.3.1 Introduction to Heat Dissipation
The upper and lower air duct for heat dissipation is formed with the combination of the
rack with other subracks, including the fan subrack, ventilation subrack, wind trap subrack,
and ventilation pannel. The fan-drived ventilation can meet the ventilation and cooling
requirement inside the subracks. The air inlet can be installed with the dustproof screen.
7.3.2 Air Duct for Heat Dissipation
The air duct for heat dissipation of ZXUR 9000 GSM is shown in Figure 7-1.
Figure 7-1 Ventilation Subrack Air Flow
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The figure above illustrates the air outlet at the top of the cabinet. The air enters the cabinet
from under the service subrack horizontally, and turns vertical after flowing through the
ventilation subrack, bringing heats from inside the cabinet to the outlet above the service
subrack. This is an efficient way of heat dissipation.
With full configuration, the cabinet has the following air flow for heat dissipation, as shown
in Figure 7-2. The air flow of each subrack is explained as follows:
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Power supply unit: bottom-up
Upper service subrack: bottom-up
Middle service subrack: bottom-up
Bottom service subrack: front-to-back
Figure 7-2 Air Flow in the Whole Cabinet
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Figures
Figure 1-1 The Context of BSC ................................................................................. 1-1
Figure 1-2 ZXUR 9000 GSM Cabinet........................................................................ 1-2
Figure 3-1 Logical Structure...................................................................................... 3-1
Figure 3-2 Cabinet Structure..................................................................................... 3-4
Figure 3-3 ETCA Subrack - Front View ..................................................................... 3-5
Figure 3-4 ETCA Subrack - Rear View...................................................................... 3-6
Figure 3-5 Software Architecture............................................................................. 3-10
Figure 4-1 Star Networking ....................................................................................... 4-1
Figure 4-2 Chain Networking .................................................................................... 4-2
Figure 4-3 Ring Networking ...................................................................................... 4-2
Figure 4-4 Star-Chain Hybrid Networking.................................................................. 4-3
Figure 4-5 Networking via the Gb Interface ............................................................... 4-4
Figure 4-6 Networking via the A Interface ................................................................. 4-4
Figure 5-1 Typical Configuration for Single Subrack.................................................. 5-3
Figure 5-2 Typical Configuration for Double Subracks............................................... 5-4
Figure 5-3 Typical Configuration for Triple Subracks ................................................. 5-5
Figure 6-1 CS User Plane Data Flow ........................................................................ 6-1
Figure 6-2 PS User Plane Data Flow ........................................................................ 6-2
Figure 6-3 Signaling Flow at the Abis Interface ......................................................... 6-3
Figure 6-4 Signaling Flow at the A Interface.............................................................. 6-3
Figure 6-5 Flow of the BTS Operation and Maintenance Data................................... 6-4
Figure 7-1 Ventilation Subrack Air Flow .................................................................... 7-3
Figure 7-2 Air Flow in the Whole Cabinet .................................................................. 7-4
I
Figures
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Tables
Table 1-1 The External System and Interfaces .......................................................... 1-1
Table 2-1 Power Specifications ............................................................................... 2-11
Table 2-2 Maximum Supported Interface Number of One Slot................................. 2-13
Table 2-3 Capacity Specifications ........................................................................... 2-14
Table 2-4 Reliability Specifications .......................................................................... 2-14
Table 3-1 Five Logical Units ...................................................................................... 3-2
Table 3-2 Front Board Functions ............................................................................... 3-6
Table 3-3 Board Interfaces ........................................................................................ 3-7
Table 3-4 Rear Boards .............................................................................................. 3-7
Table 5-1 Board Configuration List ............................................................................ 5-2
Table 5-2 Rear Board Configuration List ................................................................... 5-2
Table 5-3 OMM Client Configuration ......................................................................... 5-6
Table 7-1 Board Backup Mode Details ...................................................................... 7-2
III
Tables
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Glossary
3GPP
- 3rd Generation Partnership Project
AMR
- Adaptive Multiple Rate
APS
- Automatic Protection Switching
ATCA
- Advanced Telecommunications Computing Architecture
Abis
- Abis Interface between BSC and BTS
BSC
- Base Station Controller
BSS
- Base Station Subsystem
BTS
- Base Transceiver Station
CN
- Core Network
CS
- Circuit Switched
EDGE
- Enhanced Data rates for GSM Evolution
EFR
- Enhanced Full Rate
EMC
- Electromagnetic Compatibility
FE
- Fast Ethernet
FR
- Full Rate
GE
- Gigabit Ethernet
GERAN
- GSM/EDGE Radio Access Network
V
ZXUR 9000 GSM Product Description
GSM
- Global System for Mobile Communication
HR
- Half Rate
IMSI
- International Mobile Subscriber Identity
IP
- Internet Protocol
MGW
- Media GateWay
MS
- Mobile Station
MSC
- Mobile Switching Center
PS
- Packet Switched
QoS
- Quality of Service
SGSN
- Service GPRS Supporting Node
TBF
- Temporary Block Flow
TDM
- Time Division Multiplexing
TFO
- Tandem Free Operation
VI