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UTRAN UR11.1 Optional

Feature Description

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UTRAN UR11.1 Optional Feature Description

UTRAN UR11.1 Optional Feature Description Version Date Author Reviewer Notes

V1.70 2012/04/05 ZTE Not open to the third party

2012 ZTE Corporation. All rights reserved.

ZTE CONFIDENTIAL: This document contains proprietary information of ZTE and is not to be disclosed or used

without the prior written permission of ZTE.

Due to update and improvement of ZTE products and technologies, information in this document is subjected to

change without notice.




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FIGURES

Figure 1-1 Logical Architecture of CBS System ............. ....................... .............. ................. 7

Figure 2-1 An example of DSAR activated for both CS domain and PS domain .......... ...... 14

Figure 2-2 Enhanced Iur-g Handover Procedure ........... ....................... .............. ............... 21

Figure 2-3 Handover from UMTS to GERAN ...................... ............. ....................... ........... 24

Figure 2-4 Handover from GERAN to UMTS ...................... ............. ....................... ........... 25

Figure 2-5 Handover from UMTS to GSM ...................... .............. ....................... ............. .. 26

Figure 2-6 Handover from GSM to UMTS ............. .............. ....................... ............. ........... 27

Figure 2-7 UTRAN to E-UTRAN Inter RAT HO .......... ....................... ............. .................... 30

Figure 2-8 E-UTRAN to UTRAN Inter RAT HO .......... ............. ........................................... 31

Figure 2-9 SR-VCC................ ............. ....................... ............. .............. ....................... ...... 33

Figure 2-10 Video Call Fall-Back to Voice ...................... .............. ....................... ............. .. 41

Figure 2-11 Schematic Diagram of the Iu Flex Networking .......... ....................... ............. .. 49

Figure 2-12 Networking under MOCN Network Sharing .......................................... ........... 52

Figure 2-13 Networking under GWCN Network Sharing ....................... .............. ............... 52

Figure 2-14 Dedicated Frequency Sharing Network ........... ...................... .............. ........... 54

Figure 2-15 Four operators shared Iub interface ............ ....................... .............. ............... 58

Figure 2-16 PA Efficiency with D-PT Technology ........... ....................... .............. ............... 68

Figure 2-17 Mechanism of Four-Antenna Receiving Diversity ........... ............. .................... 72

Figure 2-18 Logical Connection of Transmit Diversity ...................... .............. .................... 74

Figure 2-19 Electrical Tilt Antenna System ........... .............. ....................... ............. ........... 75

Figure 2-20 A-RAKE receiver structure ............. ............................................. .................... 80

Figure 3-1 ATM Protocol Stack of IuCS Interface .......... ....................... .............. ............... 86

Figure 3-2 ATM Protocol Stack of IuPS Interface ........... ....................... .............. ............. .. 87

Figure 3-3 ATM Protocol Stack of Iur Interface ................................. ............. .................... 88

Figure 3-4 ATM Protocol Stack of Iub Interface ............. ....................... .............. ............... 89

Figure 3-5 AAL2 QoS Differentiation ............ ....................... .............. ...................... ........... 93

Figure 3-6 VLAN Tag ...................... ............. ....................... ............. ....................... ......... 103

Figure 3-7 PPP/MLPPP Protocol Stack ............ ............. ....................... .............. ............. 115




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Figure 3-8 Application of IEEE 1588 Clock Synchronization ...................... ............. ......... 125

Figure 3-9 IP Protocol Stack on Iub Interface............................... ....................... ............. 126

Figure 3-10 Iub Interface Transmission through the Satellite ........... ....................... ......... 128

Figure 3-11 IP Protocol Stack on IuCS Interface ............ .............. ....................... ............. 129

Figure 3-12 IP Protocol Stack on IuPS Interface ............ ....................... .............. ............. 131

Figure 3-13 DS0 Cross Connection ............. ....................... ....................... ............. ......... 132

Figure 3-14 IP Protocol Stack on Iur Interface ........... ...................... .............. .................. 138

Figure 3-15 LACP ...................... .............. ...................... .............. ....................... ............. 141

Figure 4-1 16 QAM Constellation Graph ........... ...................... .............. ....................... .... 157

Figure 7-1 Basic Principle of 2!2 MIMO Technical Solution ............. ....................... ......... 240

Figure 7-2 VAM Option with MIMO .......... ............. ....................... .............. ...................... 242

Figure 7-3 F-DPCH Multiplexed .......... ....................... .............. ...................... .............. .... 245

Figure 7-4 Enhanced UE DRX ............ ....................... .............. ............. ....................... .... 252

TABLES

Table 2-1 Types of Transmit Diversity and Physical Channel Supported by ZTE ............... 73

Table 3-1 Types of AAL Services.......................... .............................................. ............. .. 83

Table 3-2 Features of Various ATM Services.......................... .............. ....................... ...... 85

Table 4-1 HSDPA UE Category Supported by ZTE current version ........... ............. ......... 146

Table 6-1 HSUPA UE Category Supported by ZTE ............ ....................... ............. ......... 207




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1 Services and Radio Access Bearers

1.1 ZWF21-02-020 WB-AMR Speech Support

Benefits

This feature can provide high quality of voice which makes the voice more natural, and

provide high quality telephone, voice and conference video services.

Description

AMR-WB, which is the abbreviation of Adaptive Multi-Rate Wideband, is a wideband

voice coding standard adopted by both ITU-T and 3GPP. It is also called G722.2

standard. Since AMR-WB supports 50~7000Hz speech bandwidth and employs 16KHz

sampling, compared with 300 to 400Hz speech bandwidth and 8KHz sampling supported

by AMR-NB, users can feel the voice more natural, more comfortable and more

distinguishable.

ZTE RAN equipment supports all the nine speech rates of WB-AMR sessions, which are

23.85Kbps, 23.05Kbps, 19.85Kbps, 18.25Kbps, 15.85Kbps, 14.25Kbps, 12.65Kbps,

8.85Kbps, and 6.6Kbps, together with the mute rate 1.75 Kbps. The feature also

supports any combination of the above rates. Whether WB-AMR coding is used and what

rates to be used are decided by CN according to user "s signing information and the

terminal capability.

The RAB parameters of ZTE RAN equipment, used to bear sessions of AMR-WB service,

follow the definition in the 3GPP TS 34.108.

Introduced Version

U9.1&Before

Enhanced Function

No




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1.2 ZWF21-02-022 PS Signaling RAB for IMS

Benefits

This feature supports signaling transmission of IMS system (using SIP or SDP protocol).

Description

The IMS employs the Session Initiation Protocol (SIP) and the Session Description

Protocol (SDP) to control services. As defined in the 3GPP 25.862, the SIP/SDP

exclusively occupies an RAB. The SIP/SDP does not require high bandwidth, which

generally corresponds to 5% of media stream bandwidth. It has certain requirements for

delay and no packet loss is allowed. Therefore, the data transmission model is similar to

that of interactive services. But IMS signaling needs to be ensured to have a higher QoS

priority than other common traffic classes. Besides the four existing traffic classes, a new

traffic class needs to be defined to transmit SIP/SDP signaling. On the basis of

interactive services, the 3GPP has defined a new parameter to indicate that this RAB

bears SIP/SDP signaling.

For PS-based voice or video services in the IMS, the UMTS uses an interactive PDP

context to bear SIP/SDP signaling and uses another session PDP context to bear

RTP/RTCP stream. These two PDP contexts have the relationship between primary

activation and secondary activation. That is, they have the same PDP address. This

ensures that signaling flow and media stream are consistent in IP routing.

UE initiates the SIP/SDP PDP (primary PDP) activation flow first. The CN assigns an

interactive class RAB and configures signaling indication for it. This indicates that this

RAB bearer is IMS signaling and this RAB requires high priority, low delay, but small

bandwidth. Then, UE initiates the second PDP (secondary PDP) activation flow. The CN

assigns a PS conversational RAB to bear IMS voice or video packet stream. And this

RAB requires high priority and low delay.

ZTE RAN equipment supports the IMS signaling which is compliant to 3GPP TS 34.108.

According to the RAB parameters assigned by the CN, the RNC judges whether an

interactive RAB bears common user data or IMS signaling. If the interactive service

bears IMS signaling, the RNC will provide an extra QoS class for this interactive service.




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Introduced Version

U9.1&Before

Enhanced Function

No

1.3 ZWF21-02-025 Cell Broadcast Service

Benefits

This feature is used to support cell broadcast short message service and could be

utilized to deploy text broadcast services like weather forecast, traffic information and etc.

ETWS is expected to be deployed based on CBS system to alarm people in the area

where disaster, for example earthquake, typhoon and tsunami, takes place.

Description

CBS is a basic tele-service defined by UMTS to supply text broadcast service in the

mobile telecommunication system, and is called SMS-CB as well. The main difference

between CBS and SMS lies in that the receiving target of SMS is a specific user in the

network but the target of CBS involves all users in a certain area, including roaming

users. The minimal granularity of address of CBS is a cell in PLMN. The content of CBS

could be but not limited to: service notice, weather forecast, traffic information,

international and domestic news, emergency events, advertising and etc.

The logical architecture of CBS system is shown in Figure 1-1.

Figure 1-1 Logical Architecture of CBS System

Uu Iu

CellBroadcast

Center

(CBC)

UTRAN

RNCNode B

Node BUE

UE

1

RoutingNode(e.g.3G-

SGSN)

Iub

Bc




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In Figure 1-1, CBE (Cell Broadcast Entity) is the source of CBS content, interface to

information provider and is in charge of formatting CBS messages. CBC is cell broadcast

center and is in charge of the storage and the management of CBS messages. CBC

connects to RNC via Iu-BC interface standardized by 3GPP. RNC receives commands

and CBS messages from CBC and executes the broadcasting procedure in the air in the

certain area. RNC also needs to give response to the CBC inquiring and report

broadcasting states of CBS messages.

ZTE RNC supports standard Iu-BC interface and its protocol SABP (please refer to

3GPP TS25.419). ZTE RNC can be connected to one or more CBC products from the

third party with standard Iu-BC interface.

ZTE RNC also supports ETWS service (please refer to 3GPP TS 22.168) to activate user

to receive alarming CBS message in case of a disaster. To enable ETWS function, CBC

and UE are required.

Introduced Version

U9.2

Enhanced Function

No

1.4 ZWF21-02-A VoIP Package

1.4.1 ZWF21-02-021 PS Conversational RAB for VoIP

Benefits

This feature provides IMS video and voice service, that is, it provides radio access bearer

for PS AMR or WB-AMR services in PS domain. Coded voice and video data is

encapsulated in IP packets.

Description




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The IMS introduced into the R5 version by the 3GPP provides universal network

architecture of multimedia service in an IP-based network. It also makes it possible to

bear AMR or WB-AMR services based on PS. These services require higher real time

requirements than those of the interactive services, background services, and streaming

services that generally borne by PS. The CN is required to configure traffic class as

session when establishing the RAB of this type of services.

ZTE RAN equipment supports PS session services:

− According to the parameters assigned by the CN, ZTE RAN equipment can

provide a higher priority for PS session services during the packet scheduling

and RRM algorithm processing to ensure the QoS performance required by

session services, such as GBR, delay, and jitter and provide better services.

− The improved user plane supports multiple PDU lengths of RLC in UM mode

to match data load. It also reduces the padding resulting from RLC

segmentation and reassembly, and enhances the efficiency of payload

transfer rate of an air interface.

− Support the establishment of PS IMS signaling RAB to bear SIP/SDP stream.

For details, refer to the function ZWF21-02-022 PS IMS Signaling Bearer.

−

Support the reduction of IP header overhead in VoIP packets by means of thePDCP header compression algorithm. For details, refer to the function

ZWF21-06-020 Robust Header Compression.

The RAB radio parameters of ZTE RAN equipment, used to bear PS session services,

follow the definition in the 3GPP TS 34.108.

Introduced Version

U9.1&Before

Enhanced Function

No




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1.4.2 ZWF21-06-020 Robust Header Compression

l Benefits

This feature supports compressing IP header of the service data in PDCP layer to reduce

the radio bearer bandwidth required for VoIP service and enhance the capacity of system

VoIP service.

l Description

When a radio link bears VoIP service, the overhead of the IP packet header is large. A

VoIP data packet includes an IPv4 header (20 bytes), a UDP header (8 bytes), and an

RTP header (12 bytes). When IPv4 is used for bearer, VoIP protocol header needs

altogether 40 bytes; the header of IPv6 is 40 bytes; therefore, VoIP packet header

amounts to 60 bytes; but in 12.2K AMR codec voice, a frame only occupies 32 bytes.

Thus, the data payload in the VoIP packet is even smaller than the protocol header. For

a radio link which can only provide limited data bandwidth, direct VoIP service bearer will

waste a huge number of radio resources.

Between a terminal and a UTRAN access point, channelization code, scrambling or

other user IDs are used for addressing. This is a point-to-point connection and it is

unnecessary for both call parties to transfer complete RTP (RTCP)/UDP/IPv6 (IPv4)

header in each frame. IP header can be compressed through negotiation to reduce the

waste of radio resources.

However, characteristics of a radio link make a common IP header mark compression

plan unable to work well. First, a radio channel has path loss and must bear 10-1

~10-3

Bit

Error Ratio (BER); second, the Return Time (RTT) may be as long as 100ms; last but not

least, the residual BER should be taken into consideration. That is, sometimes a low

layer submits an undetected error frame to a higher layer.

The 3GPP introduces the robust header compression ROHC algorithm defined in the

RFC3095. This algorithm can effectively compress header on a link with a long RTT and

high error rate. The ROHC enhances the error recovery mechanism. Each compressed

header contains a checksum calculated according to the original uncompressed header.

Loss of synchronization of context can be repaired at the receiving terminal based on this

checksum. After the adoption of the ROHC technology, IP/UDP/RTP protocol header




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may be compressed to one byte. This greatly improves the bandwidth efficiency of VoIP

bearer on a radio link.

l Introduced Version

U9.1&Before

l Enhanced Function

No

1.4.3 ZWF23-02-005 PS Conversational RAB for VoIP over HSDPA

Benefits

This feature supports IMS video and voice services over HSDPA.

Description

This feature supports PS session RAB over an HS-DSCH channel to support AMR or

WB-AMR services in an IMS subsystem. Coded voice and video data is encapsulated in

an IP packet and transmitted. The SIP/SDP data stream and RTCP data stream of VoIP

service are characterized with bursts. The DCH bearer which employs semi-static

configuration mode is not good for the effective use of system resources. The effectivemultiplexing and fast scheduling of the HS-DSCH are better for VoIP service bearer. The

spectral efficiency of the HS-DSCH is higher than that of DCH. It also helps improve the

VoIP service capacity of the system.

For VoIP service information, please refer to the function ZWF21-02-021 PS Session

VoIP Service Bearer.

Introduced Version

U9.1&Before

Enhanced Function

No




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1.4.4 ZWF25-02-005 PS Conversational RAB for VoIP over HSUPA

Benefits

This feature supports IMS video and voice services over HSUPA.

Description

This feature supports PS session RAB over an E-DCH channel to support AMR or

WB-AMR services in an IMS subsystem. Coded voice and video data is encapsulated in

an IP packet and transmitted. The SIP/SDP data stream and RTCP data stream of VoIP

service are characterized with bursts. The DCH bearer which employs semi-static

configuration mode is not good for the effective use of system resources. The effective

multiplexing and fast scheduling of the E-DCH are better for VoIP service bearer. The

spectral efficiency of the E-DCH is higher than that of a DCH. It also helps improve the

VoIP service capacity of the system.

For VoIP service information, please refer to the function ZWF21-02-021 PS Session

VoIP Service Bearer.

Introduced Version

U9.1&Before

Enhanced Function

No

2 Radio Network Functionality

2.1 Connection Management

2.1.1 ZWF21-01-009 SIB11bis

Benefits




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This feature supports the cell System Information Block broadcast of the SIB11bis,

realizes the broadcast of more adjacent cell information over complicated networking

environment (such as dense urban area) and optimizes cell reselection of the terminal.

Description

Limited by the length of the broadcasted information block, SIB11 can broadcast

information to up to 96 adjacent cells, including intra-frequency cells, inter-frequency

cells and inter-system cells. In the complicated networking environment with multiple

frequency points, multiple frequency bands, and multiple systems, the configuration

of adjacent cell broadcasting is a bottleneck. The SIB11bis extends the adjacent

cells" broadcasting capability of SIB11 with the adjacent cell number doubled.

Introduced Version

U9.1&Before

Enhanced Function

No

2.1.2 ZWF21-01-018 Domain Specific Access Restriction (DSAR)

Benefits

This feature enables operator to efficiently control access to a specific Core Network

domain under critical conditions (e.g. emergency situations, situation of overload, etc.) to

avoid performance problems due to the user traffic"s exceeding the network capacity.

Description

A normal UMTS UE is assigned an access class (AC) randomly from 0 to 9; this is stored

in USIM card. A special UE may also be assigned an AC from 11 to 15; these would be

typically used by emergency services (for example, fireworks, ambulance). AC with 10 is

used for emergency calls. A mapping between AC and Access Service Class (ASC) is

indicated in SIB 5 or SIB 5bis. The ASC determines certain parameters for an RACH

procedure and controls the priority of the access to the RACH. A lower ASC has a higher

priority to access to the channel.




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Domain Specific Access Restriction (DSAR) enables operator to restrict the traffic load of

a specific Core Network (CN) domain. And moreover, different access restrictions can be

applied to different CN domains.

Most possibly, core network may become congested in case of football games, large

meeting presentations and etc. When a CN domain is overloaded, RAN informs UEs

belonging to some access classes (AC) that they are not allowed to access to such a CN

domain. The restriction information is broadcasted in the system information message on

AC basis sequentially. A certain proportion of AC, R%, is limited at a fixed interval. Within

the next interval, RAN limits the other R% of UEs and releases all the other UEs.

The proportion of limited AC is configurable per domain for a cell. And the restriction

interval is also configurable per cell. It is possible to have different access class

restrictions on different CN domain.

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) below gives an example as 2% of AC is prohibited from accessing

CS domain and 3% of AC are prohibited from accessing CS domain. The restriction

interval is 1 minute.

Figure 2-1 An example of DSAR activated for both CS domain and PS domain

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Timer (minute)Timer (minute)

x CS Domain

O PS Domain

When the specific CN domain recovers from overload, RAN would stop DSAR for the

domain. The operator can decide whether to trigger the DSAR function when a CN

domain is overloaded.




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Manually enabling DSAR for a domain is also supported in ZTE RAN. It is possible to

control and restrict CS traffic and PS traffic separately with more flexibility. For example,

More PS traffic may be restricted in order to leave CS capacity for users.

Logs and alarms about DSAR are provided for operator to monitor the network status.

Function of PPAC, Paging Permission with Access Control, also could be implemented

to set indicator in cell broadcast system information to allow UE responding paging

message, which is useful to avoid failure of communication between UE or emergency

service call back where access control is performed.

Introduced Version

U9.3

l Enhanced Function

No

2.1.3 ZWF21-01-020 27.2Kbps High Speed Signaling RB

Benefits

This feature helps to reduce the time delay for CS/PS service setting up, and shortenSMS services reception. It improves user experience.

Description

This feature enables the system to use the 27.2 kbps Signaling Radio Bearer (SRB)

when it establishes the RRC connection, and recovers the 3.4Kbps SRB after RAB is

established. If 27.2k SRB is set to apply on OMC, ZTE RAN will employ 27.2kbps SRB to

speed up transferring the NAS signaling messages (including location update message,

authentication message, and call setup message) between the UE and the CN.

Compared with 13.6kbps SRB, the 27.2 kbps SRB can reduce the call setup time delay

by several hundreds of ms and shorten the SMS service reception in different scenarios.

Introduced Version

U9.2




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Enhanced Function

No

2.1.4 ZWF21-01-022 Deferred SIB11/12

Benefits

When numbers of neighboring cells have been configured, reading and storing these

neighboring cells information after cell reselection or channel type switching procedure

will take a longer time. And this may result in service outrage. Deferred SIB11/12 feature

can decrease servcie outrage and enhance user experience.

Description

Due to SIB11, SIB11bis or SIB12 should be read and stored by the UE before sending

message or acting on received message on FACH after the process of cell reselection or

channel type switching, in case that a lot of neighbouring cells are configured (over 20

neighboring cells for example), this will cause the obvious interruption of services. To

solve this problem, in 3GPP R7 specification, UE is allowed to send messages through

RACH or receive messages through FACH before reading and storing SIB11/12

information.

UTRAN broadcasts through SIB3 to notice if the network supports this feature. If the

feature is applied, UE"s switching to CELL-DCH status must notify the UTRAN that

SIB11/11bis/12 are not read and stored. After switching to a non CELL-DCH status, UE

needs to complete SIB11/11bis/12 reading and storing.

This feature complies with TS 25.331 CR2557R2.

Introduced Version

U9.3

Enhanced Function

No




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2.1.5 ZWF21-01-025 Ciphering Algorithm UEA2

Benefits

Besides UEA1, an alternative encryption algorithm is offerd to make the network safer.

Subscriber class differentiated Ciphering service can be realized.

Description

This feature realizes UEA2, which is known as f8 and is specified in 3GPP R7. The

algorithm f8 is used to protect the confidentiality of the data and signaling sent between

the UE and the RNC.

The followings are the differences between UEA2 and UEA1:

− UEA1 is KASUMI based algorithm and UEA2 is SNOW 3G based algorithm.

− KASUMI is a Blockcipher with 64-bit block, 128-bit key. SNOW 3G is a 32-bit

word-oriented stream cipher generator with 128-bit key and 128-bit IV.

When a UE makes a connection with the UTRAN, the UE indicates the confidentiality

and integrity algorithms supported by the UE in MS/USIM Classmark. RNC compares the

information with the confidentiality and integrity capability when a user subscribes for the

service, then a proper algorithm is selected. Thus more and more flexible encryption

algorithms are provided.

This feature complies with the security mechanism and SNOW 3G algorithms specified

in 3GPP TS 33.102 TS 35.215~218 TS 35.919.

Introduced Version

U9.3

l Enhanced Function

No

2.1.6 ZWF21-01-026 Integrity Protection Algorithm UIA2

Benefits




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Besides UIA1, an alternative integrity protection algorithm is offerd to make the network

safer, and integrity protection can be carried out based on user level.

Description

This feature realizes UIA2, which is known as f9 and is specified in 3GPP R7. The

algorithm f9 is used to protect the integrity of the signaling sent between the UE and the

RNC.

The followings are the diffirences between UIA2 and UIA1:

− UIA1 is KASUMI based algorithm and UIA2 is SNOW 3G based algorithm.

− KASUMI is a Blockcipher with 64-bit block, 128-bit key. SNOW 3G is a 32-bit

word-oriented stream cipher generator with 128-bit key and 128-bit IV.

When a UE makes a connection with the UTRAN, the UE indicates the confidentiality

and integraty algorithms supported by the UE in MS/USIM Classmark. RNC compares

the information with the integrity capability when a user subscribes for the service and

the RNC capability, then a proper algorithm is selected. Thus more and more flexible

integrity algorithms are provided.

This feature complies with the security mechanism and SNOW 3G algorithms specified

in 3GPP TS 33.102 TS 35.215~218 TS 35.919.

l Introduced Version

U9.3

l Enhanced Function

No

2.2 Mobility Management

2.2.1 ZWF21-03-012 Transmitted Power Based Handover

Benefits




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This feature is used to guarantee user "s communication quality, avoid the interference to

other users, and optimize the system capacity.

Description

This feature contains two handover types: HO based on uplink transmitting power and

HO based on downlink transmitting power.

In the real network, there may exist such a scenario: the quality of pilot signal hasn"t

reached the threshold which can trigger the coverage based handover, but UE"s uplink

transmitting power or Node B"s downlink transmitting power has already reached a high

degree as a result of the interference or the different coverage scope between the

service channel and the pilot signal channel. In that case, increasing transmitting power

can"t guarantee UE"s QoS. To avoid the interference to other users, it is necessary to

hand over UE to other cell.

ZTE RNC equipment detects uplink transmitting power reported from UE or downlink

transmitting power reported from Node B. Once the transmitting power is higher than a

certain threshold (configured as close to the maximum transmitting power allowed in

usual), RNC can automatically initiate inter-frequency or inter-system measurement to let

UE hand over to an inter-frequency or inter-system cell which has better quality.

Introduced Version

U9.1&Before

Enhanced Function

No

2.2.2 ZWF21-03-013 Quality Based Handover

Benefits

This feature guarantees user "s communication quality, and reduces the call drop rate.

Description




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In the real network, there may exist such a scenario: the quality of pilot signal hasn"t

reached the threshold which can trigger the coverage based handover, but the UE"s

uplink quality is bad, error packet ratio is high and the target SIR value has reached the

maximum, as a result of the interference or the different coverage scope between the

service channel and the pilot signal channel. In that case, power control can "t guarantee

UE"s QoS anymore. To avoid call drop, it is necessary to hand over UE to other

inter-frequency cell.

ZTE RNC equipment detects certain user "s uplink connection. Once the quality of the

connection can"t keep the QoS and inner-loop power control has modified the target SIR

to the maximal SIR value allowed, RNC will automatically initiate inter-frequency or

inter-system measure to let UE hand over to an inter-frequency or inter-system cell which

has better quality.

Introduced Version

U9.1&Before

Enhanced Function

No

2.2.3 ZWF21-03-014 Enhanced Iur-g

Benefits

This feature supports the enhanced Iur-g interface between GERAN BSC and 3G RNC.

By employing this interface, inter-RAT handover procedure is able to be optimized, so

the time delay of the handover is shortened, the success rate of the handover is

increased, and user experience is improved. Meanwhile, the delay of handover from 3G

to 2G can be reduced.

Description

The handover between controllers includes two phases: handover preparation and

handover execution. Typically, inter-RAT handover preparation needs 600ms, which

increases the delay of handover and the possibility of resource block, namely the

handover failure and call drop rate are increased.




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ZTE develops a unique enhanced Iur-g interface to connect RNC and BSC, with

proprietary messages and the handover procedure to reduce the delay and failure rate of

inter-RAT handover. Through the enhanced Iur-g interface and its procedure, RNC and

BSC can exchange the cell load information to increase the handover success rate. The

enhanced Iur-g procedure parallels the two phases of inter-RAT handover by sending

Radio Resource Prepare message to BSC before handover is performed, as shown in

Figure 2-2. So the BSC can prepare the radio resource in advance. Compared with the

typical inter-RAT procedure, ZTE enhanced Iur-g can reduce the delay by about 200ms

to 300ms.

Figure 2-2 Enhanced Iur-g Handover Procedure

Target 2G cell information included in Radio Resource Ready message, like NACC

Related Data, cell capacity and Load/RT Load/NRT, is also used in load balancing

strategy of RRM algorithm.

Introduced Version

U9.2

Enhanced Function




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No

2.2.4 ZWF21-03-021 Hierarchical Cell Structures

Benefits

This feature supports building hierarchical cell coverage in areas with high subscriber

density to realize higher system capacity, more efficient mobility management and more

efficient radio resource management (RRM) strategy.

Description

The hierarchical cell structure (HCS) describes a wireless system in which cells of at

least two layers (such as macro cells and micro cells) are overlaid. Macro cells provide

continuous coverage, whereas micro cells absorb traffic. In general, different cells use

different frequencies. Low-mobility and high-rate UEs should camp on micro cells, while

high-mobility and low-rate UEs should camp on macro cells as much as possible so as to

reduce handover and improve the spectral efficiency and system capacity. The essential

aim of HCS is to improve network capacity and QoS.

The feature supports informing the UE whether the cell adopts HCS networking, which

priority level is chosen in HCS cell (the range is from 0 to 7, 0 is the lowest, and 7 is the

highest), and the reselection parameters in other cells in cell system information

broadcast so that the UE can camp on micro cell to absorb more traffic according to cell

reselection algorithm which is defined in 3GPP TS 25.304.

This feature also supports the detecting of user "s moving speed by RNC through

monitoring the number of times that UE changes its best cell in a certain period. If the

number is larger than a threshold, it is reasonable to consider the UE is at a high speed.

At this moment, once the UE is connected with a micro cell which uses HCS architecture,

RNC will automatically hand over it to an HCS Marco cell to reduce the handovers. On

the other hand, if the number of times is smaller than a threshold, it is reasonable toconsider the UE is static. At this moment, once UE is connected with a macro cell which

uses HCS architecture, RNC will initiate inter-frequency measurement. In the case that

micro cell can supply a better coverage, RNC will hand over the UE to an HCS micro cell

to absorb traffic and thus the capacity of the network is enhanced.




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Introduced Version

U9.1&Before

Enhanced Function

No

2.2.5 ZWF21-03-022 IMSI Based Handover

Benefits

This feature supports handover mechanisms based on user "s IMSI number.

Description

IMSI-based handover can limit the handover target cell range according to UE "s IMSI.

The scope of authorized cells based on the IMSI information on the network side can be

configured. The IMSI information is resolved through the Common ID on lu interface

during service setup or handover, and UE is not allowed to access or handover to

unauthorized cells.

ZTE RAN equipment supports that when a UE tries to access an unauthorized cell, if

there is an authorized adjacent cell with different frequency or GSM cell that has thesame coverage with the cell the UE want to access, inter-frequency hard handover flow

or inter-system handover flow will be triggered to connect the UE to an authorized cell.

Introduced Version

U9.1&Before

Enhanced Function

No

2.2.6 ZWF21-03-023 Inter-RAT PS Handover

Benefits




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This feature shortens the PS service interruption when there is a handover between

inter-RAT adjacent cells. With this feature, PS service continuity is enhanced, especially

for real-time packet service with higher QoS requirements. User experience gets

improved.

Description

Cell reselection procedure is usually executed when UE is moving between GERAN and

UTRAN. But this makes the PS service interruption last for a long time, which will

definitely affect user experience.

Inter-RAT PS handover is applicable for a UE in Cell_DCH state. The procedure of

Inter-RAT PS handover is just like the CS service inter-RAT handover. The message flow

of inter-RAT PS handover is shown as below, with message within CN omitted:

Figure 2-3 Handover from UMTS to GERAN

BSSMAP BSSMAP

PS Handover

Request ACK

RANAP RANAP

Iu Release

Complete

BSSMAP BSSMAP

PS HandoverRequest

RANAP RANAP

Relocation

Command

BSSMAP BSSMAP

PS Handover

Complete

RANAP RANAP

RelocationRequired

UE Node B RNC PS CN BSC

RRC

Handover from UTRAN

Command RRC

RANAP RANAP

Iu Release

Command

First correctly received

RLC/MAC block

(XID Resp., RAU req.

or Cell Update)

)PS handover *




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Figure 2-4 Handover from GERAN to UMTS

RANAP RANAPRelocation

RequestBSSMAP BSSMAP

RANAP RANAP

BSSMAP BSSMAP

PS Handover

Required Ack

BSSMAP BSSMAP

BSSMAP BSSMAPClear Complete

RANAP RANAP

Relocation

Complete

UE Node B RNC PS CN BSC

RRC

Handover to

UTRAN Complete RRC

RR RR

RANAP RANAP

Relocation

Detect

PS HandoverRequired

RelocationRequest ACK

PS Handover Command

Clear Command

Compared with the cell reselection, inter-RAT PS handover decreases both interruption

of data transmission and packet loss rate. And it provides better user experience of

real-time PS service with higher QoS requirements in inter-RAT moving.

Inter-RAT PS handover is not applicable unless UTRAN, GERAN, CN and UE all support

it. Otherwise, either NACC or normal cell change order will be used for PS service to

access an inter-RAT adjacent cell.

Introduced Version

U9.2

Enhanced Function

No

2.2.7 ZWF21-03-024 DTM Handover

Benefits

This feature guarantees the CS service continuity combined with PS service during

Inter-RAT moving. It improves user experience.

Description




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When a user is establishing CS service and PS service simultaneously and moving

between inter-RAT adjacent cells, CS service and PS service are handed over to

inter-RAT cell in parallel via DTM (Dual Transfer Mode) mechanism. The message flow

of DTM handover is shown as below, without the message within CN:

Figure 2-5 Handover from UMTS to GSM

BSSMAP BSSMAP

RANAP RANAP

Iu Release

Complete

BSSMAP

RANAP RANAP

UE RNC CS CN PS CN BSC

RRC RRC

RR RR

RANAP RANAP

Iu Release

Command

RANAP RANAP

RelocationRequired

Relocation

Required

BSSMAP BSSMAP

BSSMAP

PS Handover

Request

BSSMAP BSSMAP

Handover

Request Ack

Handover Request

PS Handover

Request Ack

RANAP RANAP

RANAP RANAP

( L3 information: DTM handover Command)

Command

(Target BSS to Source BSS Transpatent container:DTM h andover Command)

RelocationCommandHandover from UTRAN Command

( DTM h andover Command)

BSSMAP BSSMAPHandover Detect

BSSMAPHandover Detect

7 . Handover Complete

BSSMAPBSSMAPHandover Complete

PS Handover

CompleteBSSMAP BSSMAP

RANAP

Iu ReleaseComplete

RANAP RANAP

Iu ReleaseCommand

RANAP

BSSMAP

Relocation




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Figure 2-6 Handover from GSM to UMTS

BSSMAP BSSMAP

PS Handover

Required

RANAP RANAP

Relocation

Request Ack.

BSSMAP BSSMAP

PS Handover

Required Ack

RANAP RANAPRelocation Complete

RRC

Handover to

UTRAN Complete

RR C

RR DTM Handover Command

RR

RANAP RANAP

Relocation

Detect

BSSMAP

BSSMAP

Handover Required

RANAP RANAPRelocation Request

RANAP RANAPRelocation Request

RANAP RANAP

Relocation

Request Ack.

BSSMAP BSSMAPHandover Command

RANAP RANAP

Relocation

Detect

RANAP RANAPRelocation Complete

UE RNC CS CN PS CN BSC

Without DTM handover, for CS service and PS service in parallel, PS service does not

access inter-RAT cell until CS service completes handover to inter-RAT cell. Obviously,

DTM handover improves inter-RAT handover performance of PS service when CS

service and PS service are in parallel. It also improves user experience.

DTM handover is applicable when both UMTS system and GSM system support DTM

handover, and UE supports PS service inter-RAT handover.

Introduced Version

U9.2

Enhanced Function

No

2.2.8 ZWF21-03-025 NACC

Benefits




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This feature shortens the procedure of inter-RAT cell re-selection. It improves the

performance of the package service during inter-RAT moving. As a result, user

experience is enhanced.

Description

When a UE establishes a PS service handover to GREAN via cell reselection procedure,

the interruption of PS service is among 4 seconds to 8 seconds, which brings about bad

user experience. Network Assisted Cell Change (NACC) reduces the duration of UE

inter-RAT cell re-selection procedure.

RNC adds the SI/PSI (System Information /Packet System Information) of the target

GERAN cell in CELL CHANGE ORDER FROM UTRAN message, and transfers the

message to UE. With this information, UE doesn "t search the target cell"s system

information. Consequently, the procedure of the inter-RAT cell re-selection is shortened.

This kind of inter-RAT cell re-selection is NACC.

When an Iur-g connection works normally between an RNC and a BSC, SI/PSI of the

target GERAN cell is transferred to the RNC via Iur-g. Otherwise, the RNC initials

DIRECT INFORMATION TRANSFER message to a CN to request SI/PSI of the target

GERAN cell via the Iu connection, and the CN responses SI/PSI in DIRECT

INFORMATION TRANSFER message.

NACC is used if an RNC gets SI/PSI of the target GERAN cell and UE supports NACC.

Otherwise, inter-RAT cell reselection without network assistance is used.

Introduced Version

U9.2

Enhanced Function

No

2.2.9 ZWF21-03-026 Target cell Load based inter-RAT HO

Benefits




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This feature increases the success rate of inter-RAT handover and decreases the call

drop rate in inter-RAT handover between UMTS system and GSM system, which

improves user satisfaction.

Description

Without this feature, the load of target cell is not considered in the inter-RAT handover.

When the load of a target cell is high, inter-RAT handover is easy to fail or the quality of

service in the target system cannot get guaranteed.

The Target cell Load based inter-RAT HO enables the RNC, via an Iu connection or an

Iur-g connection, to get load information of GSM adjacent cell, or transfer load

information of UMTS adjacent cell to GSM system. The RNC selects a GSM adjacent cell

with lower load as target cell to perform handover to the GSM system.

When an Iur-g connection works normally between an RNC and a BSC, the Iur-g is

preferred to be used to exchange load information. Otherwise, the load information is

exchanged in relocation procedure via the Iu connection.

RNC will periodically update the load of adjacent GSM cells, to guarantee the availability

and correctness of adjacent cell"s load information.

This feature is applicable when the UTRAN, Core Network, GSM network and UE all

support it.

Introduced Version

U9.2

Enhanced Function

None

2.2.10 ZWF21-03-110 Handover with LTE

Benefits

This feature guarantees PS service continuous when user moving between UMTS

coverage and LTE coverage.




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Figure 2-8 E-UTRAN to UTRAN Inter RAT HO

UETarget

RNC

Forward Relocation

Request

Handover from E-UTRANCommand

Handover Required

Source

eNodeB

Relocation Request

Relocation Request Acknowledge

Source

MMETarget

SGSN

Handover Initiation

Forward RelocationResponse

Handover Command

UTRAN access procedure

Handover to UTRAN Complete

Relocation Complete

Forward RelocationComplete Notification

Forward Relocation

Complete Acknowledge

Release Resource

This feature includes dual direction handover between UMTS and LTE, and it is applied

in only PS service scenario.

Introduced Version

UR11.1

Enhanced Function

No.

2.2.11 ZWF21-03-120 SR-VCC

Benefits

This feature maintains IMS VoIP call when the LTE coverage gets worse, and allows

making use of CS domain in UMTS network for bearing voice call.




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Description

SR-VCC provides the ability to transition a voice call from the VoIP/IMS packet domain to

the legacy circuit domain. Voice call is allowed to be provided to user only when IMS

network elements are deployed in LTE network. Then a user is ongoing voice call and

the E-UTRAN coverage gets worse, via SR-VCC, the user is transited to UMTS network

and the voice call is carried by circuit domain in core network,

In case of a user establishing voice call and packet data service both in LTE network,

SR-VCC mechanism can also be used to transit user form LTE network to UMTS

network. When the user completes accessing in UMTS network, the voice call is serviced

by circuit domain core network, and the packet data service is serviced by packet domain

core network.

The signaling flow for SR-VCC during voice call and data service in combination is

shown in figure below.




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Figure 2-9 SR-VCC

13. Handover Command

1. Measurement reports

3. Handover Required

2. Decision for HO

5a. PS to CS Req

17a. Reloc/HO Complete

17b. SES (HO Complete)

17c. ANSWER

12. PS to CS Resp

18a. Reloc/HO Complete

18c. Update bearer

HSS/

HLR17e. UpdateLo

5b. Prep HO

8b. Prep HO Resp

8c. Establish circuit

6a. Forward Reloc Req6b. Reloc /HO Req

5c. Reloc /HO Req

8a. Reloc /HO Req Ack

7b. Forward Reloc Resp

7a. Reloc /HO Req Ack

11. Release of IMS accessleg

10. Session transfer andupdate remote leg

9. Initiation of Session Transfer (STN-SR or E-STN-SR)

UE Source

E-UTRAN

Source

MME

MSC Server/

MGW

TargetMSC

Target

RNS/BSS

SGW IMS

(SCC AS)

TargetSGSN

14. HO from EUTRAN command

17d. PS to CS Complete/Ack

18b. Forward Reloc Complete/Ack

16. HO Detection

4. Bearer Splitting

15. UE tunes toUTRAN/GERAN

17f. TMSI Reallocation

Introduced Version

UR11.1

Enhanced Function

No.

2.3 Radio Resource Management

2.3.1 ZWF21-04-005 AMR Rate Controlling

Benefits




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access the current cell, is refused to access the system. At the moment, ZTE RAN

decreases the allocated bit rate of the AMR call to reduce the required resource. It makes

it easier for the AMR call to access the system. At the same time, congestion control (pls

refer to feature ZWF21-04-010 Congestion Control) is triggered to recover the system

from congestion. Consequently, the success rate of AMR call establishment is increased

and the user satisfaction is improved.

If the load of a cell is a little bit higher, the bit rate of voice call (including NB-AMR and

WB-AMR) is allowed to be restricted. It means a low bit rate is assigned to voice call.

Some area such as stadium is crowed sometimes. So when RAN detects the load of

cells belonging to these area getting higher than the pre-defined threshold, RAN restricts

the AMR voice call to a level to ensure more users accessible.

The actual AMR coding rates which can be adjusted by the RNC must belong to the AMR

code set configured for users by the CN during the call establishment. The voice quality

with low-rate AMR coding is not as good as that with high-rate AMR coding, but low-rate

AMR coding has higher capacity (number of users) and wider coverage than high-rate

AMR coding. Analysis of simulation result shows that there is about 30% coverage radius

gain when the lowest AMR (4.75Kbps) instead of the highest AMR (12.2Kbps) is used.

When the lowest AMR is used, a cell will accommodate twice as many users as those

when the highest AMR is used.

Introduced Version

U9.1&Before

Enhanced Function

This feature supports AMR rate adjusting in case of admission failure or handover failure

in release U9.2.

In release U9.3, the restriction to voice call bit rate based on cell load is introduced.

2.3.2 ZWF21-04-024 User Differentiated Power Control

Benefits




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This feature allows the operator to configure a power control policy according to the

priority of the user so that the QoS of high-priority users in areas with poor network

quality can be guaranteed.

Description

Sometimes, the transmitting power of a terminal is so strong as to interfere with other

terminals, or the transmitting power of the base station targeting at a user occupies too

many downlink power resources. To avoid such event, the RNC needs to configure the

maximum uplink/downlink transmitting power allowed for each user. The ZTE RAN

supports configuring the maximum uplink/downlink transmitting power for various

services based on the priorities of these services so that users of high priority can obtain

more system resources and the QoS of users with high priority can be guaranteed even

though the network quality is poor, thus realizing differentiated QoS policy.

Introduced Version

U9.1&Before

Enhanced Function

No

2.4 QoS Guarantee

2.4.1 ZWF21-05-016 Video Call Prohibited in Specific Area

Benefits

This feature enables the system to suspend the video call service for a specific cell.

Description

The UMTS network provides the video call service. In some areas with security control or

areas with privacy protected, the video call service is prohibited and it is necessary to

suspend the service in the network layer.




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This feature provides service suspension parameters for each cell through the NMS.

Through the feature, the system can suspend specified services for specified cells. After

a service is suspended in an area, if the user initiates the service, the RNC indicates

RAB setup failure for the CN during the service setup process. If a connection has been

set up for a service, it is prohibited to hand over the service to the area where the service

is prohibited. If the CN and the UE support the feature, when the video call service is set

up or is handed over to the area where the service is closed, the RNC may roll back the

video call service into a common voice service. In this case, it is necessary to configure

the function ZWF21-05-024 video call fallback to voice call.

Introduced Version

U9.1&Before

Enhanced Function

No

2.4.2 ZWF21-05-020 RAB Negotiation & Re-negotiation

Benefits

This feature enables the system to select the QoS service for the user according to the

load of the RAN, which heightens the success rate of service access and lowers call drop

rate.

Description

The RAB QoS negotiation and re-negotiation require the cooperation between RNC and

CN. When the CN configures the RAB QoS, CN assigns the MBR (maximum bit rate)

and GBR in the RANAP message to RNC. And a new IE (Alternative RAB Parameter

Values) is adopted in the RAB assignment and relocation request message. CN will

assign another set of QoS parameter in this IE. In general, the QoS parameter in this IE

is smaller than in the normal RAB parameter. RNC will choose the QoS in these two sets

based on the current system load. If the system load is heavy, RNC will choose the QoS

set assigned in Alternative RAB Parameter Values IE to reduce the resource

consumption. When the resources of the system are scarce, the RNC selects the QoS of




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Enhanced Function

No

2.4.3 ZWF21-05-022 Service-Based Handover

Benefits

This feature supports handover strategies from UMTS to GSM according to CN

configuration so that operators can control service distribution between two networks

according to load situation or user priority.

Description

This feature decides whether to hand over and when to hand over service to GSM

according to the attribute #service handover $ in RAB assignment message:

− Handover to GSM should be performed: it means that it is necessary to hand

over to GSM as soon as possible after the service is set up successfully.

− Handover to GSM should not be performed: it means that the service will have

to hand over to GSM in the case that UMTS cannot carry the service, and RNC

will trigger inter-RAT handover in the case UMTS quality degrading.

− Handover to GSM shall not be performed: it means that this kind of service can

neither be handed over to GSM nor trigger a handover to GSM.

Regarding concurrent services, RAN network can combine service handover of multiple

services based on the priorities of service handover configured via OMC. For example,

one operator wants to have CS service in GSM network and PS services kept in WCDMA

network as long as possible. The configuration of service handover for CS service can be

#Handover to GSM should be performed$, and the configuration of service handover for

PS service can be#Handover to GSM should not be performed

$. Also

#Handover to GSM

should not be performed$ should have a higher priority than #Handover to GSM should be

performed$. Based on this configuration, while one UE has concurrent services of CS

voice and PS data, WCDMA network is still selected to provide both CS and PS services

for the user in order to guarantee PS servie experience. CS service can not be handed

over to GSM network until PS service is released.




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Figure 2-10 Video Call Fall-Back to Voice

UE Node BServing RNS

ServingRNC

CN

RRCRRC7. DCCH : Radio Bearer Reconfiguration Complete

NBAP NBAP4. Radio Link Reconfiguration Ready

NBAP NBAP 5. Radio Link Reconfigurat ion Commit

RRCRRC6. DCCH : Radio Bearer Reconfiguration

RANAP RANAP

8. RAB AssignmentResponse

RANAP RANAP

2. RAB AssignmentRequest

[Modification]

NBAP NBAP3. Radio Link Reconfiguration Prepare

RANAP RANAP

1. RAB ModificationRequest

The video call service, as a special feature in UMTS system, has been applied

extensively. But the GSM system cannot provide the video call service. As a result, the

video call service in the UMTS network cannot be switched to the GSM system. If the

video call service has to be switched to the GSM system, it may be interrupted forcedly.

This feature enables the system to roll back from the video call service to AMR service

and then implement handover from the 3G system to the 2G system, thus ensuring the

continuity of the voice service.

The implementation of the feature requires the cooperation from the CN and UEs that

support the SCUDIF function.

Introduced Version

U9.1&Before

Enhanced Function

No




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2.5 User Plane Process

2.5.1 ZWF21-10-001 Cell ID & RTT Positioning

Benefits

This feature supports location service based on cell ID. Cell ID positioning does not

require additional hardware and investment is little. It provides large coverage and rapid

positioning delay, suitable for location service with low requirement on accuracy.

Description

When a location request is received from CN, a proper location method is selected

according to the requirement on accuracy. After UE position is calculated, the result is

reported to CN.

According to the reporting method involved in the location request, the RNC reports

service area (SA) or geographical area (GA) to CN.

− SA mode

RNC reports the SA ID (SAI) of the cell where the UE camps to CN.

−

GA mode:

When there is no information about accuracy in the location request, the

coverage information (usually pre-configured in OMC) of the cell where the UE

camps is reported.

When accuracy requirement is indicated to be greater than a specific value

(usually 100 meter), cell ID + RTT method is used, which means UE position is

determined by Time of Arrive (TOA). Round Trip Time (RTT) is the time

difference between the start of a downlink frame and the reception of the

corresponding uplink frame. TOA can be derived by the NodeB RTT

measurement and the UE Rx-Tx time difference measurement. Type 2

measurement on UE Rx-Tx is adopted with priority Type 1 is used if UE does

not support type 1.




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Cell ID + RTT positioning has an accuracy of 80-100m. But it requires that Node B should

support RTT measurement. Otherwise, only cell ID positioning is used.

According to the location request from CN, RNC reports position results immediately or

when SA where UE resides changes.

Introduced Version

U9.1&Before

Enhanced Function

No

2.5.2 ZWF21-10-002 AGPS

Benefits

This feature provides high-accuracy position service with large coverage, rapid location

and quick response.

Description

To use the A-GPS location service, the UE and radio access network must support GPS.

Compared with the traditional GPS, A-GPS system sends GPS location reference

information (encapsulated in system broadcast SIB15 or measurement control message)

from the network side to the mobile UE to help it acquire satellite signal and

measurement code phase information quickly. Therefore, A-GPS locates UE quickly with

rapid response, reducing power consumption of the UE.

A-GPS positioning methods are classified into two modes: UE-assisted (UE-A) and

UE-based (UE-B).

In the UE-A A-GPS location method, location calculation is achieved by the Service

Mobile Location Center (SMLC) at the network side. UE reports measurement results of

the satellite signals and code phase information to the RNC at the network side. The

RNC transmits the measurement results to the SMLC through the Iu-PC interface. The

SMLC then calculates the mobile location based on the measurement results and finally

reports the calculation result to the CN through the RNC. In the UE-B A-GPS method,




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location calculation is achieved by UE and UE reports the calculation result to network

side. For the A-GPS, the location result is reported with ellipsoid point with altitude and

uncertain Ellipsoid.

ZTE RNC completes location calculation with their built-in Iu-PC interfaces and SMLC

function, helping the operators reduce the cost for purchasing additional SMLC devices.

The accuracy of A-GPS positioning has an advantages of 5 to 50 meter over the cell

ID+RTT methods.

According to the location request from the CN, the RNC can report the measurement

results immediately or when SA where UE resides changes.

Additional GPS antenna and the feeder are needed because they are not included inRNC and Node B equipment.

Introduced Version

U9.1&Before

Enhanced Function

No

2.5.3 ZWF21-10-003 Emergency Call Re-direct to GSM

Benefits

If location service is not provided in UMTS system, or accuracy of location service in

UMTS system is not high, this feature makes use of location service in 2G network to

give the location information of a user in an emergency call. With the location information,

emergency assistance could be provided in time by some rescue organization.

Description

Emergency call is always requested by a user in certain emergency situations. If the

location of a user in emergency is identified, assistance would be provided without delay.

When location service is not provided in UMTS system or the accuracy of location




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service in UMTS system is not high, UMTS system redirects emergency call to 2G

network. Then the location of the user is got via 2G network "s location service.

When the Flag related to Emergency Call Re-direct to GSM is on, if a UE transfers RRC

CONNECTION REQUEST message with a cause of Emergency Call, and the cell where

the message is received has more than one co-located GSM adjacent cell, ZTE RAN

responds RRC CONNECTION REJECT message with the co-located GSM cell

information to the UE. Then the UE performs inter-RAT cell reselecting to the GSM cell

and makes an emergency call again. User does not feel the procedure of re-direction to

GSM, and it seems that the emergency call is launched in GSM network originally.

Introduced Version

U9.2

Enhanced Function

No

2.5.4 ZWF21-10-004 LCS Classified Zones

Benefits

This feature enables operators to acquire the information of specific areas when a UE

enters or leaves these areas so that operators can deliver user-location-based services.

Description

ZTE RAN equipment can specify areas (usually a cell or a set of cells) in OMC. When a

UE enters or leaves these areas, the RNC automatically reports location information of

the UE to the CN by SA method.

With this feature, operators can deliver user-location-based services such as alarm

messages to UEs when they enter these areas.

Introduced Version

U9.1&Before




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Enhanced Function

No

2.5.5 ZWF21-10-005 LCS over Iur

Benefits

Increase the precision of location service, including CellID based LCS, CellID+RTT

enhanced LCS, UEB AGPS LCS, LCS Classified Zones

Description

Generally the realization of LCS is limited in the scenario, where the best cell of the

active set of the UE is only in the SRNC, and the measurement of RL of inter Iur can"t be

done. The feature LCS over Iur supports UE"s LCS even when some RLs in DRNC .

If the best RL in the active set is in DRNC, LCS information and NodeB measurement

result are exchanged through Iur between SRNC and DRNC,

− Cell ID LCS, Cell ID+RTT enhanced LCS

When the best cell is in the DRNC, SRNC obtains the location information of the

reference cell through iur information. For the Cell ID+RTT, SRNC needs to startthe RTT measurement on DRNC side through Iur common measurement

procedure.

− UEB AGPS

When the best cell is in the DRNC, the SRNC obtains the accessory GPS

information of the reference cell on the DRNC side through initiating Iur information

exchange procedure

− LCS Classified Zones

Supporting Iur direct neighbor cell reported as LCS Classified Zones

Introduced Version

UR11.1




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Enhanced Function

No

2.6 RAN Management

2.6.1 ZWF21-20-017 Intelligent Carrier Power Off/On

Benefits

This feature enables the system to close some carrier frequencies in the multi-carrier

sector when the traffic volume is very low, thus reducing power consumption of

equipments and the operator's OPEX.

Description

The load of the telecom system varies greatly within a day. During peak traffic hours in

the daytime, the system needs multiple carrier frequencies (for example, S333) to carry

services; at night, one carrier frequency (S111) is enough. When the traffic volume is

very low, the system still uses multiple carrier frequencies to carry services. Though the

load of each carrier frequency is not very high, each carrier frequency needs common

channels such as the pilot channel. The power of the common channels covers 20% ofthe transmitting power of the overall carrier frequencies.

The intelligent carrier power off/on technology of the ZTE RAN can automatically monitor

the network service status. When the traffic volume is relatively low, the RAN

automatically closes idle carrier frequencies. If the RAN finds that the traffic volume

increases to such a threshold that the current working carrier frequencies cannot handle

the extra services, it starts the closed carrier frequencies.

When the traffic volume is very low and it is necessary to close some carrier frequencies,

the intelligent carrier power off/on technology can gradually reduce the maximum

transmitting power of a cell until the RF units on the redundant carrier frequencies are

switched off. In this way, the small traffic in the closed cell can hand over to the adjacent

cell smoothly.




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Introduced Version

U9.1&Before

Enhanced Function

No

2.7 Enhanced RAN Functionality

2.7.1 ZWF21-30-021 Iu Flex

Benefits

This feature supports that one RNC can be connected to multiple MSC Servers/SGSNs

and these MSC Servers/SGSNs are combined into a pool to provide redundancy so as to

improve the network security, helping to achieve load balance between MSC

Servers/SGSNs and reducing waste of hardware resource and signaling overhead.

Description

The Iu Flex is a networking technology in the 3GPP R5 version. This networking mode

eliminates the restriction that one RNC can be connected to only one MSC Server/SGSN

in a traditional network. In the Iu Flex networking, one RNC can be connected to multiple

MSC Servers/SGSNs, and these MSC Servers/SGSNs are grouped to a pool area which

provides services to the RNC. As shown in Figure 2-11, a pool area is set according to

different CN domains. All the connected CS CN nodes constitute a CS pool area, and all

the connected PS CN nodes constitute a PS pool area.




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Figure 2-11 Schematic Diagram of the Iu Flex Networking

Compared with traditional networks, the networking based on the Iu Flex technology has

the following advantages:

−

Load sharing and disaster recovery

The capacity of an RNC has been increased, even higher than that of an MSC

Sever or SGSN. In traditional networking, the actual capacity of RNC has been

restricted since only one MSC Server/SGSN is allowed to connect to one RNC.

With all MSC Servers/SGSNs forming a pool area, the capacity of all CN

nodes in pool area are combined to connect to more RNCs. Network load is

shared among MSC Servers/SGSNs. And the CN nodes in pool area back up

for each other. If one is down, the traffic of the CN node is transferred to other

CN nodes.

− Reducing signaling load of mobility, increasing the actual capacity of the

network

If there are too many subscribers, equipment capacity will be a limitation and

Area 1

RAN

node

Area 5

RAN

node

Area 6

RAN

node

Area 7

RAN

node

Area 8

RAN

node

Area 2

RAN

node

Area 3

RAN

node

Area 4

RAN

node

PS pool-area 2PS pool-area 1

CS pool-

area 2CS pool-

area 1

MSC 3MSC 2

MSC 1

MSC 6MSC 5

MSC 4

SGSN 6

SGSN 2

SGSN 1

SGSN 5

SGSN 4

SGSN 3

MSC 7




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then the coverage of a single MSC Server/SGSN will be small. When UEs

move between the different CN nodes frequently, there are many signalings of

the LA/RA update, handover, relocation and the exchange of the HLR

parameters. With Iu Flex networking, a subscriber within one pool area can

enjoy his/her services provided by a specific MSC Server/SGSN, and need not

change serving CN node when moving within the pool area. So signaling load

caused by mobility is decreased significantly and the system capacity and the

network performance also get improved effectively.

ZTE RAN supports Iu Flex networking, that is multi MSC Servers/SGSNs can be

connected to one RNC. Network Node Selection Function (NNSF) is used to select a

serving CN node among multi CNs when a subscriber accesses the network or the

network pages a subscriber:

− When users initiate attach procedure or LA/RU update procedure, RNC will

select CN node based on NRI configuration and IDNNS information to

establish a signaling connection, which reduces signaling interaction of

mobility between CN nodes.

− If there is no NRI information or CN nodes have problems or the CN load is

high, the RNC will reselect a CN node to establish a signal and traffic

connection so as to achieve load-sharing and redundancy protection.

− When a user has a terminated call, the RNC will buffer the CN node

identification for utilization in future paging procedure to select a correct CN

node.

− Configuration of Preferred Pool Area (PPA) supported, the CN equipment in

PPA pool will be selected with a higher priority to serve UE. This feature can

increase the flexibility of Iu Flex configuration.

ZTE RAN equipment can recognize CN ID (Global CN-ID) in RANAP procedure of SRNS

relocation, the CN reset, the resource reset and the overload in the case of Iu Flex

networking, and it only processes messages from some specific CN nodes.

ZTE RAN equipment supports the combining of MBMS service of multiple SGSNs in the

case of Iu Flex networking.




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Introduced Version

U9.1&Before

Enhanced Function

No

2.8 ZWF21-30-A RAN Sharing Package

2.8.1 ZWF21-30-100 Basic RAN Sharing Support

Benefits

This feature allows multiple operators to use the same UTRAN resources to provide their

own services. In this way, the operator can shorten the network construction, save the

investment on site acquisition, site construction, transmission construction, and wireless

network devices, and greatly decrease the cost in network construction and operation.

Description

ZTE RNC can be connected to one or more CN equipments belonging to multiple

operators, allowing multiple operators to share many kinds of UTRAN resources and

equipments including RNC cabinet and boards, OMC devices, Node B cabinets,

baseband processing boards, RF units and feeder cable system, and other RAN

auxiliaries (including power and transmission lines of the Iub/Iur interface).

ZTE RAN supports two UTRAN network sharing modes defined by the 3GPP:

− Multi-Operator Core Network (MOCN)




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Figure 2-12 Networking under MOCN Network Sharing

Radio Access Network

Operator X

CN

Operator A

CN

Operator B

C N

Operator C

RNC

Iu

Node B Node B

In this network sharing mode, different operators construct CN devices

separately. All CN devices are connected to the same RNC and share the

RAN resources.

− Gateway Core Network (GWCN)

Figure 2-13 Networking under GWCN Network Sharing

Radio Access NetworkOperator X

SharedMSC/SGSN

SharedMSC/SGSN

SharedMSC/SGSN

RN C

Iu

CN

Operator A

CN

Operator B

CN

Operator C

RNC RNC

In this network sharing mode, the operators share the same CN network (suchas MGW, MSC server, and SGSN) as the network gateways and connect to

their respective HLR, GGSN, GMSC, GMGW, and billing & accounting

system.




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ZTE UTRAN supports flexible UTRAN sharing deployment. Part of RNS could be set not

shared or shared by different operators from other parts. Iu Flex also can be activated to

MSCs of one or several operators.

Introduced Version

U9.1&Before

Enhanced Function

No

2.8.2 ZWF21-30-101 RAN Sharing with Dedicated Carrier

Benefits

This feature enables operators to use their own frequency when they share the UTRAN

network. It can prevent the capacity competition of radio resources among several

operators.

Description

If different operators have their own frequency resources, the ZTE RAN equipment

enables the operators to share the UTRAN network with their respective frequencies. Allthe UTRAN equipment and resources will be shared except the frequency. The

frequencies of different operators can be deployed in one Node B, sharing the cabinet,

power, and baseband processing boards. According to the operator "s requirements,

these operators can share the FR devices (power amplifier, feeders, and antenna), or

deploy them separately. The frequencies of different operators can also be deployed in

different Node Bs and connected to the same RNC through the Iub interface. Different

operators can share the RNC cabinet, power source, and processing boards in the

control plane and user plane.




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Figure 2-14 Dedicated Frequency Sharing Network

Frequency one

Frequency two

Shared RNC

Frequency one

Frequency two

Shared Node B

MNC

one

MNCtwo

Operator one

Operator two

The frequencies of different operators can be distinguished according to the PLMN code

in the broadcasted system information. Through the broadcasted information of each

carrier, UE can identify the networks of different operators, camping on and accessing to

carriers with its home PLMN or authorized PLMN, and displaying the logo of the operator.

According to the access frequency of the UE, RNC routes signaling connection and

servi

zte wcdma features

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