Post on 28-Apr-2015
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Introduction to 3G/UMTS Introduction to 3G/UMTS Signalling and InterfacesSignalling and Interfaces
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Module topics
• Introduction to 3G/UMTS signalling
• Transport layer signalling and interfaces
• Control layer signalling and interfaces
• User layer signalling and interfaces
• Summarised function of the 3G/UMTS interfaces
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Bearer & Signalling
UE BTS RNC
Uu Iub/Iur Iu
Core Network
MSC
3G
SGSN
RNCWCDMA BTS
Keypoint:
Define signalling - Communication between different network elements, control processes, enable bearers/communication.
Signalling protocols - standardised set of rules on how the communication should take place, what messages to exchange, etc.
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3G/UMTS Session Management
CNRAN
RRC Connection
UE
CircuitSwitchedNetwork
PacketNetwork
Radio Access Bearer
Speech Service
Video Service
Radio Access BearerPacket Data Service
Radio Access Bearer
RANAP Connection
RANAP Connection
Key points:
RAB - Radio Access Bearer = service connection between the terminal and the core network.
User plane = User Data.
Signalling links are used to inform the different network elements on how to control the Radio Resource Connection.
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BS RNCMTUSIM Core Network Domains:
- MSC & GMSC (Circuit Switched)
- SGSN & GGSN (Packet Switched)
3G network structure
Access Stratum
Serving Stratum
Application Stratum
Stratum is collection of protocols
ATM
SignallingProtocol
User Data
The different Stratums:
- Access Stratum: Message Flows, rules and procedures on how to establish the connection between the MT and the network (RNC).
- Serving Stratum: Signalling messages that are used to enable/establish services (bearer setup).
- Application Stratum: High-layer stratum, which contains signalling procedures to enable the usage of applications. When connecting to external networks (such as the Internet), the protocols and procedures must of course be supported all the way between the end-points.
Compare this with the serving stratum and application stratum, which are both defined internally in the UMTS network.
3GPP 23.101.
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OSI model
Transport Layer Transport Layer
Session Layer Session Layer
Presentation Layer Presentation Layer
Application Layer Application Layer
User Data Control Data
Network Layer
Data (Link) Layer
Physical Layer
User Plane Control Plane
Transport Plane
Access Stratum
Serving StratumApplication
Stratum
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General protocol modelfor UTRAN terrestrial interfaces
TransportNetworkLayer
RadioNetworkLayer
ALCAP(s)
Signalling Bearer(s)
Application Protocol
Signalling Bearer(s)
Data Stream(s)
Data Bearer(s)
User PlaneControl Plane
TransportNetwork
Control Plane
TransportNetwork
User Plane
TransportNetwork
User Plane
Physical Transmission layer
ALCAP Access Link Control Application Part
All UTRAN-related issues are visible only in the radio network layer
Used for all 3G specific control signalling such as setting up bearers to the UE
- RANAP in Iu - RNSAP in Iur - NBAP in Iub- etc.
Always set up by O&M
Used for all control signalling within the transport network layer
Used to set up and tear down data bearers for the user plane
Always set up by O&M
•Horizontal Layers
The protocol structure consists of two main layers, the Radio Network Layer and
the Transport Network Layer. All UTRAN related issues are visible only in the Radio Network
Layer. The Transport Network Layer represents standard transport technology that is selected
to be used for the UTRAN but without any UTRAN specific changes.
•Vertical Planes
⇒Control Plane
The Control Plane is used for all UMTS specific control signalling. It includes the
Application Protocol (i.e. RANAP in Iu, RNSAP in Iur, NBAP in Iub) and the Signalling
Bearer for transporting the Application Protocol messages.
The Application Protocol is used, among other things, for setting up bearers to the
UE (i.e. the Radio Access Bearer in Iu and subsequently the Radio Link in Iur and Iub).
The Signalling Bearer for the Application Protocol is always set-up by O&M
actions.
The protocol structures in UTRAN terrestrial interfaces (Iu, Iur, Iub) are designed according to the same
general protocol model. The structure is based on the principle that the layers and planes are logically
independent of each other and, if needed, parts of the protocol structure may be changed in the future
while other parts remain intact.
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Transport plane (≈≈≈≈Access Stratum)
• Defines how physical connection is established between the mobile terminal and the network
• In the Uu interface, WCDMA/FDD is used
• In the UTRAN interfaces, ATM will be used:
- Iub
- Iur
- Iu-CS, Iu-PS
BS RNCMTUSIM
Access Stratum
CN
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Synchronous and Asynchronous Multiplexing
CACCC
A A
C C C C
A
CACAB
A A
BB B BB B B B
BB BB B
C
ABC
Asynchronous Multiplexing
Synchronous Multiplexing
C
BB
CC
B
C
• Asynchrounous Multiplexing can utilise the transmission capacity more flexibly
• ATM provides a "bit pipe" by providing Virtual Circuits
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Why is the ATM selected as a transport network in 3G?
• ATM provides efficient support for transmission of voice, data, and video
• ATM provides QoS guarantee and reliability
• ATM utilises statistical multiplexing, so
less bandwidth can be reserved
transmission cost saving are considerable
• ATM supports the soft handover functionality
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ATM cell
• Always the same payload - 48 bytes (octets)
• Overhead is almost 9.5%, due to the 5-octet header
• Can carry any type of information
• Two types of ATM cells
• ATM UNI (User-Network Interface) cell; used for communicationbetween ATM endpoints and ATM switches
• ATM NNI (Network-Node Interface) cell; used forcommunication between ATM switches
Header5 bytes
Payload48 bytes
53 bytes
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Virtual Path (VP)
Virtual Channel (VC)
ATM CellVirtual Channel
Virtual Path
• Virtual Channel = Virtual Circuit
• Virtual Paths = Logical grouping of Virtual Circuits → an ATM switch can perform operations on groups of Virtual Circuits
• Transmission Path= A bundle of Virtual Paths
Virtual Path, Virtual Channel, Transmission Path
Virtual Path is a semi-permanent connection simultaneously handling many virtual connections/channels. Actual data is transferred in ATM cells over the Virtual Channels
A group of Virtual paths between two network elements forms a Transmission Path.
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Transmission Path, VP, VC and ATM Cell
Transmission pathVirtual PathVirtual Channel (VC)ATM Cell
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ATM resource management (Iu-CS)
RNC MGW
AT
M lo
gic
al in
terfa
ce
VP
Ltp
,V
PL
tp,
VP
Ltp
,
VC
Ltp
AT
M lo
gic
al in
terfa
ce
For RANAP, AAL2 (MTP3SL) signalling
VC
Ltp
VP
Ltp
,V
PL
tp,
VC
Ltp
VC
Ltp
User traffic
VC
Ltp
3
1
4
2
Access profile of ATM interface- max bandwidth- max VPI/VCI bits- max VPC/VCC
- VPI- VPL service level: VP/VC- usage e.g. MTP3SL, AAL2UD, IPOAM, AAL2SL, DNBAP, CNBAP- service category: CBR/UBR- traffic and QoS parameters
- interface id- UNI / NNI- IMAGR/PET/ SET
- VCI- service category- traffic and QoS parameters
O&M traffic (UBR, IPOAM)
Signalling traffic (CBR, MTP3SL)
User traffic (CBR, AAL2UD)
User traffic
VC
Ltp
VP
Ltp
,V
CL
tpV
CL
tp
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ATM UNI cell header - Content
VCI
GFC VPI
VPI
VCI
VCI PT CLP
HEC
123457 68
Payload
Header
(5 bytes)
Payload
(48 bytes)
GFC Generic Flow Control
GFC Provides local functions, such as identifying multiple stations that share a
single ATM interface. This field is typically not used and is set to its default value.
VPI Virtual Path Identifier
VPI: In conjunction with the VCI, identifies the next destination of a cell as it passes
through a series of ATM switches on the way to its destination.
VCI Virtual Channel Identifier
VCI: In conjunction with the VPI, identifies the next destination of a cell as it passes
through a series of ATM switches on the way to its destination.
PT Payload Type
PT: Indicates in the first bit whether the cell contains user data or control data. Ifuser data, the second bit indicates congestion, and the third bit indicates whether
the cell is the last in a series of cells that represent a single AAL5 frame.
CLP Cell Loss Priority
CLP: Indicates whether the cell should be discarded if there is congestion in thenetwork. If the CLP bit equals 1, the cell should be discarded in preference to cells
with the CLP bit equal to zero.
HEC Header Error Control
HEC: Calculates checksum only on the header itself.
Any cell that fails the header error check is instantly discarded by the network.
Generic Flow Control (GFC)Provides local functions, such as identifying multiple stations that share a single ATM interface. This field is typically not used and is set to its default value.
Virtual Path Identifier (VPI)In conjunction with the VCI, identifies the next destination of a cell as it passes through a series of ATM switches on the way to its destination.
Virtual Channel Identifier (VCI)In conjunction with the VPI, identifies the next destination of a cell as it passes through a series of ATM switches on the way to its destination.
Payload Type (PT)Indicates in the first bit whether the cell contains user data or control data. If the cell contains user data, the second bit indicates congestion, and the third bit indicates whether the cell is the last in a series of cells that represent a single AAL5 frame.
Congestion Loss Priority (CLP)Indicates whether the cell should be discarded if there is congestion in the network. If the CLP bit equals 1, the cell should be discarded in preference to cells with the CLP bit equal to zero.
Header Error Control (HEC)Calculates checksum only on the header itself. Any cell that fails the header error check is instantly discarded by the network.
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ATM protocol layers
• Physical layer defines the transmission medium.
• ATM layer inserts and extracts the cell header. It also takes care of multiplexing and switching of cells.
• AAL maps user data from higher layer into standard ATM cells to be transported over an ATM network. It also collects information from ATM cells for delivery to higher layers.
PHYSICAL LAYER
ATM LAYER
AALATM ADAPTATION LAYER
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ATM layer functions
Convergence Sublayer (CS)
PayloadPayload HeaderHeader
48 bytes5 bytes
User data
AAL
Segmentation and Reassembly Sublayer (SAR)
ATM Layer
Transmission Convergence (TC)
48 bytes
Physical Medium Dependent(PMD)
SD
H O
/H
PayloadHeader
Scramble frame and adapts the signals to the optical or electrical transmission medium
STM-1 Frame
Physical Layer
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ATM Adaptation Layer
Typical
Use
FixedConnection
Video&
Audio
FrameRelay
IPServices
AAL AAL1 AAL2 AAL3/4 AAL5
Connection OrientedConnection oriented or
connectionless
Synchronised Not Synchronised
Constant VariableBit Rate
Source & Dest.
Connection
ATM Layer
Physical Layer
A B C D
ATM Service Classes
Convergence Sublayer
Segmentation and ReassemblySublayer
AAL
CS
SAR
Higher Protocol Layers
ATM Layer
AAL2 is seen as a suitable option for Iu-CS (Circuit Switched), Iur, and Iub user plane connections
AAL5 is seen suitable for control information and Iu-PS (Packed Switched) user plane data transfer.
The main difference between AAL2 and AAL5 is that AAL2 requires timing between the source and destination. AAL2 is thus suitable for real-time services such as speech, while AAL5 works fine in a non real-time environment.
************************************************************************************************
AAL is divided into two sublayers: CS (Convergence sublayer) and SAR (Segmentation and Re-assembly sublayer). The CS sublayer adapts AAL to the upper protocol layers and the SAR splits data to be transmitted into suitable payload pieces, and in receiving direction it collects payload pieces and unites them back to original data flow. Depending on the case, the CS sublayer may be divided further on into smaller entities.
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ATM protocol for signalling and user data
Physical layer
ATM layer
SignallingAAL
AAL
Signalling protocol User data
C-Plane U-Plane
AAL 2 – Iu-CS
AAL5 – Iu-PSAAL 5
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Iu Transport PlanesRNCBS
Physical Layer Physical Layer
ATM ATM
AAL2 AAL2AAL5 AAL5
Control
Data
Control
Data
User
Data
User
Data
Iub
DRNCSRNC
Physical Layer Physical Layer
ATM ATM
AAL2 AAL2AAL5 AAL5
Control
Data
Control
Data
User
Data
User
Data
Iur
RNC
Physical Layer Physical Layer
ATM ATM
AAL2 AAL2AAL5 AAL5
Control
Data
Control
Data
User
Data
User
Data
Iu-CSCS Core Network Domain
RNC
Physical Layer Physical Layer
ATM ATM
AAL5 AAL5AAL5 AAL5
Control
Data
Control
Data
User
Data
User
Data
Iu-PSPS Core Network Domain
In the Iub interface the transport plane consists of ATM (Asynchronous Transfer Mode) and its adaptation layer(s) located on top of the physical layer. The physical layer could be any media providing constant bit rate with adequate bandwidth, that is, PCM(s), PDH or SDH.
In the Iur interface between SRNC and DRNC the construction of the transport plane is similar as in the Iub, and in the Iu-CS interface too!
=>In all Iub, Iur and Iu-CS interfaces ATM uses two adaptation layers: AAL2 and AAL5.
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Iu -CS UP
A/µ-law,PCM,UDI,etc.
WCDMAL1
MAC
RLC-U
E.g. Vocoder
PHY
ATM
AAL2
FP
WCDMAL1
PHY PHY
ATM ATM
AAL2 AAL2
FP
MAC
RLC-U
PHY PHY
ATM
AAL2
Iu -CS UP
E.g. Vocoder
Link Layer
PHY PHY
Link Layer
A/µ-law,PCM,UDI,etc.
PSTNN-ISDN
PSTNMGW MSCRNCBSUE
A BIu-CSIubUu
PHY
ATM
AAL5
SSCOP
SSCF-UNI
PHY
ATM
AAL5
SSCOP
SSCF-NNI
MTP3b
SCCP
RANAPNBAP
PHY
ATM
AAL5
SSCOP
SSCF-UNI
NBAP
PHY
ATM
AAL5
SSCOP
SSCF-NNI
MTP3b
SCCP
RANAP
PHY
TDM
MTP
SCCP
BSSAP
PHY
TDM
MTP
SCCP
BSSAP
UNI NNI
USER PLANE
CONTROL PLANE
Protocol Stack for Circuit Switched Data
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Protocol Stack for Packet Switched Data
PHY
ATM
AAL5
SSCOP
SSCF-UNI
PHY
ATM
AAL5
SSCOP
SSCF-NNI
MTP3b
SCCP
RANAPNBAP
PHY
ATM
AAL5
SSCOP
SSCF-UNI
NBAP
PHY
ATM
AAL5
SSCOP
SSCF-NNI
MTP3b
SCCP
RANAP
RNC SWU MSC
GTP-U
UDP
ATM ATM
WCDMAL1
MAC
RLC-U
PDCP
E.g.IPv4, IPv5
PHY
ATM
FP
PHY PHY
AAL2AAL2WCDMAL1
AAL5
FP LLC/SNAP
MAC IP
RLC-U
PDCP
ATM
AAL5
LLC/SNAPLink
Layer
IP IP
GTP-U
UDP
PHY PHY PHY
LinkLayer
IP
UDP
E.g. IPv4, IPv5
PHY
GTP-U GTP-U
UDP
IPnetwork
SGSN GGSNRNCBS
Iu-PSIubUu
UNI NNI
USER PLANE
CONTROL PLANE
Gn Gi
UE
SAAL NNISAAL UNI
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CCS7 lower layers (review from GSM courses)
Message Transfer Part (MTP)
Data Link Layer
Physical Layer
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Signalling network(review from GSM courses)
Node A Node B
Node C
SignallingRoutes
Signalling Route Set
SPC SPC
STP
Terminology: Terminology:
• Signalling Point
• Signalling Transfer Point
• Signalling Link
• Signalling Link Set
• Signalling Route
• Signalling Route Set
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Transport network control plane
TransportNetworkLayer
RadioNetworkLayer
ALCAP(s)
Signalling Bearer(s)
Application Protocol
Signalling Bearer(s)
Data Stream(s)
Data Bearer(s)
User PlaneControl Plane
TransportNetwork
Control Plane
TransportNetwork
User Plane
TransportNetwork
User Plane
Physical Transmission layer
For setup connection of Transport Network Layer
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Main interfaces in Release 3MSC
TCSM
RAN Mobility Core
BSCMSC
MGW
2GSGSN
3G
SGSN
RNC
RNC
A
Iu-PS
Gb
Iu-CS
Abis
Iub
IurIPBB
HLR
GGSNIP Backbone
GSM BTS
Triple Mode BTS
WCDMA BTS
WCDMA BTS
PSTN
NMS
The focus in this chapter is to look at the interfaces and protocols.
Earlier, we have been more element-orientated (Architecture Module) and Traffic Management orientated.
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Control plane (≈≈≈≈ Serving Stratum)Main protocols:Main protocols:
• NBAP Node B Application Part - Iub interface
• RNSAP/Radio Network Subsystem Application Part → Iur interface
• RANAP/Radio Access Network Application Part→ Iu interfaces (CS and PS)
• Also MAP and ISUP are presented
BS RNCMT
Access Stratum
Serving Stratum
ATM
USIM CN
SignallingProtocol
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Iub interface (NBAP)
RNCBS
Physical Layer Physical Layer
ATM ATM
AAL5
NBAP NBAP
Convergence Protocol(s) Convergence Protocol(s)
AAL5
Iub
Common NBAP procedures:Common NBAP procedures:
• Create UE contexts (needed before dedicated signalling procedures can take place).
• Control BCCH information
Dedicated NBAP procedures:Dedicated NBAP procedures:
• Related to specific UE context, examples:
• Radio link addition,reconfiguration, deletion
• Downlink power control
• Dedicated measurement signalling
Common NBAP procedures are used to create new User Equipment (UE) contexts and control BCCH broadcast information. The Iub always contains one signalling link for the common NBAP procedures, and there may be several signalling links for dedicated NBAP procedures.When a UE establishes connection to the network, the control plane is taken into use.After establishing the control plane, the UE may start to use its own applications, which may require signalling too (user plane).Control plane means the signalling resources attached for signalling connection set-up issues between two signalling nodes. In case of Iub interface, the control plane is established between the BS and the RNC, and signalling connection set-up case is radio link set-up.
From Specs: Rel'99; 24.433: "" The NBAP protocol provides the following functions:
- Cell Configuration Management. This function gives the CRNC the possibility to manage the cell configuration information in a Node B.- Common Transport Channel Management. This function gives the CRNC the possibility to manage the configuration of Common Transport Channels in a Node B.- System Information Management. This function gives the CRNC the ability to manage the scheduling of System Information to be broadcast in a cell.- Resource Event Management. This function gives the Node B the ability to inform the CRNC about the status of Node B resources.- Configuration Alignment. This function gives the CRNC and the Node B the possibility to verify and enforce that both nodes have the same information on the configuration of the radio resources.- Measurements on Common Resources. This function allows the Node B to initiate measurements in the Node B. The function also allows the Node B to report the result of the measurements.- Radio Link Management. This function allows the CRNC to manage radio links using dedicated resources in a Node B.- Radio Link Supervision. This function allows the CRNC to report failures and restorations of a Radio Link.- Compressed Mode Control [FDD]. This function allows the CRNC to control the usage of compressed mode in a Node B.- Measurements on Dedicated Resources. This function allows the CRNC to initiate measurements in the Node B. The function also allows the Node B to report the result of the measurements.- DL Power Drifting Correction [FDD]. This function allows the CRNC to adjust the DL power level of one or more Radio Links in order to avoid DL power drifting between the Radio Links.- Reporting of General Error Situations. This function allows reporting of general error situations, for which function specific error messages have not been defined.- Physical Shared Channel Management [TDD]. This function allows the CRNC to manage physical resources in the Node B belonging toShared Channels (USCH/DSCH).- DL Power Timeslot Correction [TDD]. This function enables the Node B to apply an individual offset to the transmission power in each timeslot according to the downlink interference level at the UE.""
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ATM resource management (Iub)
RNC BS
AT
M lo
gic
al in
terfa
ce
VP
Ltp
,V
PL
tp,
VC
Ltp
AT
M lo
gic
al in
terfa
ce
VP
Ltp
,V
PL
tp,
3
1
42
Access profile of ATM interface- max bandwidth- max VPI/VCI bits- max VPC/VCC
- VPI- VPL service level: VP/VC- usage e.g. MTP3SL, AAL2UD, IPOAM, AAL2SL, DNBAP, CNBAP- service category: CBR/UBR- traffic and QoS parameters
- interface id- UNI / NNI- IMAGR /PET /SET
- VCI- service category- traffic and QoS parameters
O&M traffic (UBR, IPOAM)
Signalling and user traffic (CBR, AA2SL, DNBAP, CNBAP, AAL2UD)
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
VC
Ltp
Common NBAP signalling
Dedicated NBAP signalling
Dedicated NBAP signalling
SAAL UNI (AAL2) signalling
SAAL UNI (AAL2) signalling
User traffic
User traffic
User traffic
VC
Ltp
VC
Ltp
VP
Ltp
,
User traffic
WAM
WAM
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Iur interface (RNSAP)DRNCSRNC
Physical Layer Physical Layer
ATM ATM
AAL5
RNSAP RNSAP
Convergence Protocol(s) Convergence Protocol(s)
AAL5
Iur RNSAP protocol functionsRNSAP protocol functions
Some examples:
• Radio link management and supervision
• Physical channel reconfiguration
• Measurements, dedicated resources
From the specifications Rel 99; 25.423:
""The RNSAP protocol provides the following functions:
- Radio Link Management. This function allows the SRNC to manage radio links using dedicated resources in a DRNS; - Physical Channel Reconfiguration. This function allows the DRNC to reallocate the physical channel resources for a Radio Link;- Radio Link Supervision. This function allows the DRNC to report failures and restorations of a Radio Link;- Compressed Mode Control [FDD]. This function allows the SRNC to control the usage of compressed mode within a DRNS;- Measurements on Dedicated Resources. This function allows the SRNC to initiate measurements on dedicated resources in the DRNS. The function also allows the DRNC to report the result of the measurements;- DL Power Drifting Correction [FDD]. This function allows the SRNC to adjust the DL power level of one or more Radio Links in order to avoid DL power drifting between the Radio Links;- CCCH Signalling Transfer. This function allows the SRNC and DRNC to pass information between the UE and the SRNC on a CCCH controlled by the DRNS;- Paging. This function allows the SRNC to page a UE in a URA or a cell in the DRNS;- Common Transport Channel Resources Management. This function allows the SRNC to utilise Common Transport Channel Resources within the DRNS (excluding DSCH resources for FDD);- Relocation Execution. This function allows the SRNC to finalise a Relocation previously prepared via other interfaces;- Reporting of General Error Situations. This function allows reporting of general error situations, for which function specific error messages have not been defined.- DL Power Timeslot Correction [TDD]. This function enables the DRNS to apply an individual offset to the transmission power in each timeslot according to the downlink interference level at the UE.""
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Signalling example: Radio link setup
RACH-Short Initial Access RRC Connection Request
Radio Link Setup
RRC Conn. Request AckFACH - Access Granted
Radio Link Setup Response
Synchronisation IndicatedUL DPCCH
4
DRNC SRNCBSUu Iub Iur
Radio Link Setup Response
Radio Link Setup
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Iu interface (RANAP)
Core NetworkDomains
RNC
Physical Layer Physical Layer
ATM ATM
AAL5
RANAP RANAP
Convergence Protocol(s) Convergence Protocol(s)
AAL5
IuRANAP protocol functionsRANAP protocol functions
Some examples:
• RAB management
• Controlling overload in Iu
• Paging users
• Controlling security in UTRAN
• Location reporting/control
From the Specs, Rel'99, 25.413: ""RANAP protocol has the following functions:
- Relocating serving RNC. This function enables to change the serving RNC functionality as well as the related Iu resources (RAB(s) and Signalling connection) from one RNC to another.- Overall RAB management. This function is responsible for setting up, modifying and releasing RABs.- Queuing the setup of RAB. The purpose of this function is to allow placing some requested RABs into a queue, and indicate the peer entity about the queuing.- Requesting RAB release. While the overall RAB management is a function of the CN, the RNC has the capability to request the release of RAB.- Release of all Iu connection resources. This function is used to explicitly release all resources related to one Iu connection.- Requesting the release of all Iu connection resources. While the Iu release is managed from the CN, the RNC has the capability to request the release of all Iu connection resources from the corresponding Iu connection.- SRNS context forwarding function. This function is responsible for transferring SRNS context from the RNC to the CN for intersystem forward handover in case of packet forwarding.- Controlling overload in the Iu interface. This function allows adjusting the load in the Iu interface.- Resetting the Iu. This function is used for resetting an Iu interface.- Sending the UE Common ID (permanent NAS UE identity) to the RNC. This function makes the RNC aware of the UE's Common ID.- Paging the user. This function provides the CN for capability to page the UE.- Controlling the tracing of the UE activity. This function allows setting the trace mode for a given UE. This function also allows the deactivation of a previously established trace.- Transport of NAS (non-access stratum )information between UE and CN (ref. [8]). This function has two sub-classes: 1. Transport of the initial NAS signalling message from the UE to CN. This function transfers transparently the NAS information. As a consequence also the Iu signalling connection is set up.2. Transport of NAS signalling messages between UE and CN, This function transfers transparently the NAS signalling messages on the existing Iu signalling connection. It also includes a specific service to handle signalling messages differently.- Controlling the security mode in the UTRAN. This function is used to send the security keys (ciphering and integrity protection) to the UTRAN, and setting the operation mode for security functions.- Controlling location reporting. This function allows the CN to operate the mode in which the UTRAN reports the location of the UE.- Location reporting. This function is used for transferring the actual location information from RNC to the CN.- Data volume reporting function. This function is responsible for reporting unsuccessfully transmitted DL data volume over UTRAN for specific RABs.- Reporting general error situations. This function allows reporting of general error situations, for which function specific error messages have not been defined.""
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The path of the bearer through the network
IuCN Circuit Domain: - RT Traffic - Constant Bit Rates
CN Packet Domain: - NRT Traffic (RT Traffic) - Variable Bit Rates
RAB4
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Radio Access Bearer assignment
RAB Assignment Complete
RAB Assignment Request
4
RNCBSUu Iub Iu Core Network
Domains
RAB is configured to be used over the existing Radio Link(s)
Core Network always initiate RAB
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Serving RNC Relocation
IuIur Iu
Relocation Required
Relocation Command
SRNC Relocation Commit
Relocation Detect
Relocation Complete
Relocation Request
Reloc. Req. Ack.
Relocation Detect
Relocation Complete
Core NetworkDomain(s)
SourceServingRNC
TargetServingRNC
RAB(s) Assigned
RAB(s) Released
Iu Release
To the target RNC withRNSAP:
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Core network MAP (optional topic)
MSC VLR
A(u)C EIRHLR
MAP-B
MA
P-C M
AP-D
MAP-G
MA
P-F
MAP-E To/from other MSC
To/from other VLR
L1L2
L3
SCCP
TCAP
MAP
CCS7 Protocol Stackwithin Circuit SwitchedCore Network Branch:
MTP
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Packet switched interfaces (optional topic)
3G RAN
Interface Legend:UuIuGcGfGiGnGr
= Interface between UE (User Equipment) and RAN= Interface between RAN and CN= G interface between Gateway GSN and HLR= G interface between Serving GSN and EIR= G interface between Gateway GSN and IP network= G interface between Serving and Gateway GSN= G interface between Serving GSN and HLR
IP Network(s)
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User plane (≈≈≈≈ Application Stratum)
• Signalling between the UE and the destination (for instance an application server).
• In the Uu interface, user plane is DPDCH plus the data it carries.
• User planes for other interfaces are shown in the following fourfigures.
BS RNCMTUSIM
Access Stratum
Serving Stratum
Application Stratum
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User plane in the Iub interface
RNCBS
Physical Layer Physical Layer
ATM ATM
AAL2
Frame Protocols for:
DCH, RACH and FACH
Frame Protocols for:
DCH, RACH and FACH
AAL2
Iub
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User plane in the Iur interface
DRNCSRNC
Physical Layer Physical Layer
ATM ATM
AAL2
Frame Protocols forDCH and CCH
Frame Protocols forDCH and CCH
AAL2
Iur
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User data on the Iu-CS interface
Core Network
Circuit Switched Domain
RNC
Physical Layer Physical Layer
ATM ATM
AAL2
User Data Streams User Data Streams
AAL2
Iu-CS
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User data on the Iu-PS interface
Core Network
Packet Switched Domain
RNC
Physical Layer Physical Layer
ATM ATM
AAL5
IP
UDP
GTP
User Data Streams
IP
UDP
GTP
User Data Streams
AAL5
Iu-PS
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IP/UDP relationship (optional topic)
Network Layers
(OSI 1 - 3)
Transport Layer
Session Layer
Presentation Layer
Application Layer
IP
UDP
GTP
Selected applications for selected purposes
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IP/TCP relationship (optional topic)
Network Layers
(OSI 1 - 3)
Transport Layer
Session Layer
Presentation Layer
Application Layer
IP
TCP
Telnet FTP SMTP IMAPHTTP
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Summary of UMTS signalling and interfaces
The next two slides summarise the implementation of different interfaces with respect to:
• RAN interfaces
• Core network interfaces
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RAN interfaces
BS Functions:- Modulation- Rate Matching- Error Protection in Uu Interface- Uu Interface Channelisation- Macro Diversity (Softer Handover)
Uu Interface:Transport Plane
Control Plane
User Plane
Procedures
- WCDMA (Wideband CodeDivision Multiple Access)
- DPDCH and DPCCH Channels
- Optimised, application-relatedprotocols suitable for bothpacket and circuit switchedtraffic
- Radio Link (RL) Setup- RL Reconfiguration- RL Addition- RL Deletion- Radio Access Bearer Mgmt
Iub Interface:Transport Plane
Control Plane
User Plane
Procedures
- ATM
- Communication Control Ports- Node B Control Ports
- RACH/FACH/DCH Data Portsforming UE Context(s)
- Radio Link (RL) Setup- RL Reconfiguration- RL Addition- RL Deletion- Power Control Information- Handover Signalling- Measurement Reports
Iur Interface:Transport Plane
Control Plane
User Plane
Procedures
- ATM
- SCCP over CCS7
- Frame Protocols for DedicatedChannels over ATM
- Radio Link (RL) Setup- RL Reconfiguration- RL Addition- RL Deletion- Power Control Information- Handover Signalling- Measurement Reports
Iu Interface for CN Packet Domain:Transport Plane
Control Plane
User Plane
Procedures
- ATM
- RANAP over CCS7 or IP
- GTP (GPRS TunnellingProtocol) over UDP/IPover AAL5
- Radio Access Bearer Management- SRNC Relocation- Direct Transfer Procedures(Direct Signalling between UEand the CN Packet Domain)
Iu Interface for CN Circuit Domain:Transport Plane
Control Plane
User Plane
Procedures
- ATM
- RANAP over CCS7
- Optimised, application-relatedprotocols over ATM AAL2
- Radio Access Bearer Management- SRNC Relocation- Direct Transfer Procedures(Direct Signalling between UEand the CN Circuit Domain)
4
BS
BS RNC
RNC
RNC Functions:Radio Resource Management
Telecommunication Management
- Admission Control- Code Allocation- Load Control- Power Control- Handover Control (HO)- Macro Diversity (Soft HO)
- Radio Access Bearer (RAB)- RAB - Radio Link Mapping
47 © NOKIA Kittipong Thamapa
Core networkinterfaces
HLR&AC&EIR
MSC&VLR GMSC (&VLR)
Iu PSTN
Gi
3G RAN
Iu Interface for CN Packet Domain:Transport Plane
Control Plane
User Plane
Procedures
- ATM
- RANAP over CCS7 or IP
- GTP (GPRS TunnellingProtocol) over UDP/IPover AAL5
- Radio Access Bearer Management- SRNC Relocation- Direct Transfer Procedures(Direct Signalling between UEand the CN Packet Domain)
Iu Interface for CN Circuit Domain:Transport Plane
Control Plane
User Plane
Procedures
- ATM
- RANAP over CCS7
- Optimised, application-relatedprotocols over ATM AAL2
- Radio Access Bearer Management- SRNC Relocation- Direct Transfer Procedures(Direct Signalling between UEand the CN Circuit Domain)
VLR - VLR MM:Transport Plane
Control Plane
User Plane
Procedures
- CCS7
- CCS7 MTP,SCCP and MAP
- Security ParameterTransfer
MSC - MSC Traffic & MM:Transport Plane
Control Plane
User Plane
Procedures
- CCS7
- CCS7 MTP & ISUPand MAP for MM
- Traffic Path Setup (ISUP)- MSC-MSC Handover (MAP)
MSC/VLR - HLR MM:Transport Plane
Control Plane
User Plane
Procedures
- CCS7
- CCS7 MTP,SCCP and MAP
- Location Enquiry- Roaming Nbr Allocation- Location Registration- Security Parameter Alloc.
SGSN - GGSN:Transport Plane
Control Plane
User Plane
- ATM
- IP (GTP)
- IP
GGSN - Public IP:Transport Plane
Control Plane
User Plane
- ATM
- IP
CN Service Domain:Transport Plane
Control Plane
User Plane
- CCS7
- CCS7, MTP,SCCP, MAP,INAP, CAMEL
48 © NOKIA Kittipong Thamapa
3G/UMTS Signalling and Interfaces
Review Questions
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Review (1/7)
PCM
ISUP
ATM
RANAP over CCS7
Iu-PS
RANAP over CCS7,(later also over IP)
ATM
RNSAP
Iub
ATM
NBAP
MSC
TCSM
RAN
Mobility Core
BSCMSC
ATM
Module
2G
SGSN
3G
SGSN
RNC
RNC
Gb
Abis HLR
ControlTransportInterface
PCM
LapD
A
ControlTransportInterface
PCM
BSSAP
ControlTransport
Iu-CS
ControlTransportInterface
ControlTransportInterface
ATM/IP
Iur
ControlTransportInterface
ControlTransportInterface
GSMBTS
WCDMABTS
PSTN
50 © NOKIA Kittipong Thamapa
Review (1/7)MSC
TCSM
RAN
Mobility Core
BSCMSC
ATM
Module
2G
SGSN
3G
SGSN
RNC
RNC
Gb
Abis HLR
ControlTransportInterface
PCM
LapD
A
ControlTransportInterface
PCM
BSSAP
ControlTransport
Iu-CS
ControlTransportInterface
ControlTransportInterface
ATM
Iur
ControlTransportInterface
ControlTransportInterface
GSMBTS
WCDMABTS
PSTN
51 © NOKIA Kittipong Thamapa
Review (2/7)
2. Which of the following sentences about the Radio Access Bearer is true?
a. The RAB carries a connection between the terminal and the corenetwork.
b. The RAB is a radio link signalling protocol.c. Voice is the only information on a RAB.d. All of the above.
3. Which of the following sentences about the RRC is true?
a. The RRC is the connection between the terminal and the core network,upon which traffic is transferred.
b. The RRC is the connection between the terminal and RAN andcontains the RABs.
c. The RRC is the connection between the RAN and core network andcontains all the RABs from different terminals.
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Review (3/7)
4. Which of the following sentences about the ATM connection is correct?
a. The virtual channels contain virtual paths for the data.b. There is one virtual path per virtual channel.c. One virtual circuit contains at the most one virtual channel.d. One virtual path can contain many virtual channels.
5. In the RNC, what is the function of the MAC (Medium Access Control)?
a. Selection of data to be inserted in Radio Frame.b. Selection of common channels.c. Multiplexing of logical channels to transportation channels.d. Ciphering for real-time traffic.e. All of the above.
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Review (4/7)
6. Which of the following sentences best describes the function and role of the NBAP protocol?
a. It is the protocol used between the network and the PSTN and usedfor call set-up purposes.
b. It is the protocol used between two RNCs. It is used when one RNCneeds to signal a cell in an URA and when performing softhandovers.
c. It is the protocol used between the core network and the RNC andused for the management of resources.
d. It is the protocol used between the RNC and the BTS and used tocontrol the allocation of resources.
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Review (5/7)
7. Which of the following sentences best describes the function and role of the RANAP protocol?
a. It is the protocol used between the network and the PSTN andused for call set-up purposes.
b. It is the protocol used between two RNCs and used when oneRNC needs to signal a cell in an URA and performing softhandovers.
c. It is the protocol used between the core network and the RNCand used for the management of resources.
d. It is the protocol used between the RNC and the BTS and usedto control the allocation of resources.
55 © NOKIA Kittipong Thamapa
Review (6/7)8. Which of the following sentences best describes the function and role of
the RNSAP protocol?
a. It is the protocol used between the network and the PSTN and used forcall set-up purposes.
b. It is the protocol used between two RNCs. It is used when one RNCneeds to signal a cell in an URA and when performing soft handovers.
c. It is the protocol used between the core network and the RNC and usedfor the management of resources.
d. It is the protocol used between the RNC and the BTS and used to controlthe allocation of resources.
56 © NOKIA Kittipong Thamapa
Review (7/7)
9. Which of the following sentences best describes the function and role of the ISUP protocol?
a. It is the protocol used between the network and the PSTN and usedfor call set-up purposes.
b. It is the protocol used between two RNCs. It is used when one RNCneeds to signal a cell in a URA and when performing softhandovers.
c. It is the protocol used between the core network and the RNC andused for the management of resources.
d. It is the protocol used between the RNC and the BTS and used tocontrol the allocation of resources.