04 umts traffic managementnew
DESCRIPTION
umts traffic managementnewTRANSCRIPT
1 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
UMTS Traffic ManagementUMTS Traffic Management
5 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
UMTS architecture
FiberFiber
AXC
ATM Access
Internet
RAN (UTRAN & GERAN) Core Network
Control Plane
Gateway Plane
PSTN2G
SGSN3G
SGSN GGSNRNC
BSC
Node B
Node B
Node B
HLR &AuC
3GMSC
SCEP
SMSC
BTS
7 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
UMTS network databases
FiberFiber
AXC
ATM access
Internet
Mobility CoreRAN
Control Plane
Gateway Plane
PSTN2G
SGSN3G
SGSN GGSNRNC
BSC
TripleModeBTS
GSMBTS
WCDMABTS
HLR AuCEIR
3GMSC
SMSC
Used as an intermediate store for SMS
Contains subscriber IDs, service information and location attributes. In
AuC subscriber security information and in some
implementations EIR
Used to support
subscriber services
Contains temporary
information on subscriber
Contains temporary
information on the subscriber
SCEP
9 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
FiberFiber
AXC
ATM Access
Internet
RAN (UTRAN & GERAN) Core Network
Control Plane
Gateway Plane
PSTN2G
SGSN3G
SGSN GGSNRNC
BSC
Node B
Node B
Node B
HLR &AuC
3GMSC
SCEP
SMSC
BTS
Unique subscriber identities
MSISDN = CC + NDC + SN
one or more MSISDN is
assigned to a subscriber for
different services
IMSI = MCC + MNC + MSIN
IMSI uniquely identifies each
subscriber.
10 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
FiberFiber
AXC
ATM Access
Internet
RAN (UTRAN & GERAN) Core Network
Control Plane
Gateway Plane
PSTN2G
SGSN3G
SGSN GGSNRNC
BSC
Node B
Node B
Node B
HLR &AuC
3GMSC
SCEP
SMSC
BTS
Temporary subscriber identities
P-TMSI is allocated for
packet transactions by
the SGSN.
The TMSI/TMUI is generated by
the VLR and used for CS transactions
11 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
FiberFiber
AXC
ATM Access
Internet
RAN (UTRAN & GERAN) Core Network
Control Plane
Gateway Plane
PSTN2G
SGSN3G
SGSN GGSNRNC
BSC
Node B
Node B
Node B
HLR &AuCEIR
3GMSC
SCEP
SMSC
BTS
Mobile terminal security
RANThe IMEI is used to track legal mobile
equipment (optional)
12 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
What is the bearer?
UE Node B RNC
Uu Iub/Iur Iu
Core Network
UE Node B RNC
Uu Iub/Iur Iu
Core Network
Data/Wireless Protocols are transparent to surrounding network
MGW
The MGW for 3G-MSC performs speech transcoding
13 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Bearer characteristicsD O C U M E N T T Y P E 1 ( 1 )
M o b i l e P h o n e sT y p e Y o u r N a m e H e r e T y p e D a t e H e r e
C o n v e r s a t i o n a l c l a s s V o i c e a n d v i d e o
S t r e a m i n g c l a s s S t r e a m i n g v i d e o
I n t e r a c t i v e c l a s s W e b b r o w s i n g
B a c k g r o u n d c l a s s M a i l d o w n l o a d i n g
14 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Types of bearer
VoiceVoice Messages
MessagingTransactionalInfoservices
WWW browsingIntranet accessDownloading
Audio Streaming
0 8 16 32 48 64 80 96 112 128 144 160 kbit/s
Video StreamingVideotelephony
UE Node B RNC
Uu Iub/Iur Iu
Core Network
• A bearer has different parameters, such as variable data rates, protection and delay.
• The bearer is dependent on the service required.
15 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Transmission over the network
PSTN
3GSGSN
GGSN
RNC
HLR AuCEIR 3G
MSC
Internet
Channels from the air-interface along the Iub Interface
Physical channels in the air-interface are separated by codes
ATM link to the MGW at the MSC
Packets are tunneled to the SGSN
Packets tunneled from the SGSN to the GGSN
Packet Data
Dedicated circuit
Student Exercise:Why do you think the RNC makes the decision on the type of bearer that is allocated to a subscriber?
16 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Layers - Bearer services in UMTSTE MT UTRAN CN Iu
EDGENODE
CNGateway
TE
End-to-End Service
TE/MT LocalBearer Service
UMTS Bearer Service External BearerService
UMTS Bearer Service
Radio Access
Bearer Service
CN BearerService
BackboneBearer Service
Iu BearerService
Radio BearerService
UTRAFDD/TDD
Service
PhysicalBearer Service
18 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
4
RAB (Radio Access Bearers) and RRC (Radio Resource Connection)
CNRAN
RANAP Connection
Radio Access Bearer
RANAP Connection
Radio Access Bearer
RRC Connection
UE
PacketNetwork
Circuit SwitchedNetwork
Packet Data Service
Speech Service
Video Service
Radio Access Bearer
Student Exercise:Can you think of an example where it may be necessary to modify the radio resource connection?
19 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
4
Example: RAB Establishment (simplified)
4
Uu Iub Iu
RAB Assignment Request
RAB Assignment Complete
SGSNRNC
Node B
Iub bearer set-up(AAL 5 virtual channel)
Iub bearer set-up(AAL 2 virtual channel)
Radio Bearer Set-up Complete
Radio Bearer Set-up
Radio Link Reconfiguration
Radio Link Reconfiguration Complete
20 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Management of the radio bearer
3GSGSN
RNC
3GMSC
RNC
RNC
Mobile has a single RRC
21 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Management of the radio bearer
3GSGSN
RNC
3GMSC
RNC
RNC
As the subscriber moves a second connection is made for a cell on the same
site (softer handover)
22 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Management of the radio bearer
3GSGSN
RNC
3GMSC
RNC
RNC
As the mobile continues then the first link is dropped, and a second cell is
added from another site (soft handover)
NOTE: Those BTS with an active connection are known to be part of the active set.
23 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Management of the radio bearer
3GSGSN
RNC
3GMSC
RNC
RNC
As the mobile continues then the second link is dropped, and a second cell is added from
another RNC. A soft handover is possible as the Iur interface exists.
The RNC is known as the serving(S-RNC) and the new RNC is the drift
(D-RNC). Note that the Iu connection is still from the S-RNC.
24 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Management of the radio bearer
3GSGSN
RNC
3GMSC
RNC
RNC
As the mobile continues, the third connection is dropped. The S-RNC has no active connection's
itself, so the Iu-RRC connection is moved to the D-RNC.
25 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Management of the radio bearer
3GSGSN
RNC
3GMSC
RNC
RNC
Finally, the mobile is now in area where the forth connection is dropped and the new site selected is under another RNC. The S-RNC does not have an Iur interface to the target RNC, so the core network is used to assist
in the handover.
26 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Mobility Management - the role of the HLR
The HLR is a centralised database, which contains
information about the subscriber, location and service information. In
the Nokia Solution authentication
information is also stored in the HLR.
3GSGSN GGSN
RNC
3GMSC
3GSGSN
GGSN
RNC
3GMSC
3GMSC
Core Network
Foreign Network
Radio AccessHLR AuCEIR
Supplementary Services Location Updating
Locating the Subscriber
Service Information
27 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Cellular architectureLA = Location Area (MSC)RA = Routing Area (SGSN)URA = UTRAN Registration Area (RNC)Cell = Cell (RNC)
CELL
URACEL
L
URA
ROUTING
AREA (RA)
CELL
Position = Positioning Service (UTRAN)
CELL
CELL
CELL
CELL
CELL
CELL
CELL
CELL
ROUTING
AREA (RA)
Location Area (LA)
CodeLAMNCMCCLAI CILACodeMCCMNCCGI
Page 29
28 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
UTRAN Registration Area - URA3G
SGSNHLR &AuC
RNC RNC RNC
URA URA URAURAURAURA
3GMSCIf the LA or RA changes
RNC will ensure updated information is sent to the
core network.
As the subscriber moves from one URA to another, then a URA_update is performed.
29 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Location based information
• Information about the actual position of the subscriber (~40-70m) can be stored and used by the emergency services.
• This information can also be used to provide mobility services.
BTS
BTS
BTS
Page 32
30 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Location updating
3GSGSN
3GMSC
RNC
RNC
HLRWhen switching on/off
IMSI Attach/Detach
When moving from area to area - Update on cell/LA/RA/URA level
If the VLR is not informed about the user then the data
is removed
VLR
The RNC keeps track of the mobiles within the
URAs. It also informs the core network when the
subscriber moves between RAs and LAs.
The SGSN keeps track of the mobiles
Periodically over time if mobile does perform an update
31 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Routing area update
SGSN-1
RNC-1
RA-1
Old cell New cell
32 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Mobility Management of states in the SGSN
D etach D etachP acke tA ttach
P acke tA ttach
P acke t R eceived P acke t R eceived
R ad io L ink R e lease Iu C onnection R e lease
MM States in UE: MM States in SGSN:
33 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Paging the subscriber
BTS BTS
Paging
BTS
Mobile responds to paging
Routing Area
Paging
Paging
34 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Network roaming
3GSGSN
HLR
3GSGSN
3GMSC
RNC
HLR
3GMSC
RNC
BSC
BSC
Home Network
Visitor Network
International Network
3. Network Confirm access
1. User requests access (IMSI Attach)
2. If operators have a roaming agreement, information is copied to visitor network (from VLR/HLR)
35 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Mobility Management procedures• Location Registration (Circuit and Packet Switched)
• Location Update (Circuit Switched)
• IMSI Attach/Detach (Circuit Switched)
• Routing Area Update (Packet Switched)
• Cell Attach/Detach (Packet Switched)
• Location Info Retrieval (Circuit and Packet Switched)
• Paging (Circuit Switched)
• Paging (Packet Switched)
• Authentication Procedure (Circuit/Packet Switched)
• Ciphering Procedure (Circuit/Packet Switched)
• UE Identity Checking (Circuit/Packet Switched)
• UE Hardware (IMEI) Checking (Circuit/Packet Switched)
36 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Session Management
Mobility Management (MM)
Session Management (SM)
Communication Management (CM)
Radio Resource Management (RRM)
UE RAN CN
Fiber Fiber
AXC
ATM Access
Internet
RAN (UTRAN & GERAN) Core Network
Control Plane
Gateway Plane
PSTN2G
SGSN3G
SGSN GGSNRNC
BSC
Node B
Node B
Node B
HLR &AuCEIR
3GMSC
SCEPSMSC
BTS
37 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Gaining initial access to the network
3GSGSN
3GMSC
RNC
HLR
Previous cell is tried and if not there the terminal scans
frequencies and applies codes. If possible home
network is selected.
Networks transmit information about
themselves (MCC+MNC)
Operator A (frequency 1)
Operator B (frequency 2)
Operator C (frequency 3)
38 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
IMSI Attach when a subscriber is registered
in another VLR
3GSGSN
RNC
HLRACEIR
3GMSC
3GMSC
RNC also keeps information about subscribers within
the URA.
1. Request Location Update (IMSI Attach)
1,
2. New VLR requests and receives authentication information and IMSI from previous VLR.
2,
3. Authentication request and response
3,
4. New MSC/VLR updates HLR with new location. HLR sends acknowledgement and subscriber information. 4,
6. TMSI/TMUI allocation/acknowledgement and Location Update acknowledgement
6,
5. HLR cancels the old location, old VLR sends acknowledgement
5,
39 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Requesting a bearer
3GSGSN
3GMSC
RNC
HLR1. Mobile sends a request for a bearer (on RACH and listens for reply)
2. RNC will allocate a bearer for the subscriber
Mobile in idle mode and camping on a
cell.
40 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Authentication
3GSGSN
3GMSC
RNC
HLR
The HLR contains information on the subscriber, terminal,
location and services. Authentication codes and
keys are stored and generated in the AuC
The SIM and terminal contain
authentication keys
The IMSI and IMEI are checked (optional and at a changeable interval)
Information is checked from the HLR
41 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Authentication Data Request andAuthentication Data Response
VLR AuC
RAND K SQN
XRES AUTN CK IK
IM SI
RAND, AUTN, XRES, CK, IK
SG SN
42 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
User Authentication
VLR
RAND, AUTN
RES
RAND K AUTN
RES SQN CK IK
U E SG SN
VLR/S GS N checkswhether RES = XRE S
UE checks whether theSQ N is b ig enough
43 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Ciphering on radio path
3GSGSN
3GMSC
RNC
HLR
Authentication codes are used to create a signal which is scrambled with
the data. It is almost impossible to decode the signal without knowing
the keys
Ciphering is performed in the
RNC and the mobile
In UMTS, multiple air-interface channels are
used in the connection to the mobile
45 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
UE BS BSCRNC BTS MSMSC/VLRMSC/VLR HLR
9. HLR Enquiry
10. Send Routing Information (MSRN)
11. Call Setup Continues
13. Paging Response
14. Setup
15. Call Confirmed/Alert16. Conversation
5. Call Setup
7. RAB Setup / Radio Link Modification
6. Bearer Assignment Request (Create) - Bearer Parameters and Binding ID
8. Bearer Assignment Complete
4. RRC Setup Complete
2. Radio Link Setup
3. Radio Resource Connection Setup
1. Radio Resource Connection Request
12. Paging
Simplified UMTS-GSM call setup
46 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Simplified steps - PDP Context Activation
UE BS RNC 3G-SGSN DNS GGSN-1
GTP PDU
12. Bearer Assignment Complete
1. Radio Resource Connection Request
2. Radio Link Setup
3. Radio Resource Connection Setup / Complete
4. PDP-Context Activation Request: Access Point Name (APN), QoS, IP Address
11. RAB Setup / Radio Link Modification
13. PDP Context Activation Accept: NSAPI, given dynamic IP-address, offered QoS
10. Bearer Assignment Request (Create): NSAPI, offered QoS
5. Authentication
8. Create PDP Context Request; APN, Dynamic IP Address
PDP PDU
6. GGSN address resolution Request (APN)
7. GGSN address resolution Response (192.10.45.1 = GGSN-1)
9. Create PDP Context Response; Dyn. IP-address, Charging Id
GGSN selects the Access Point and assigns dynamic IP Address
GTP PDU
47 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Packet states
- P D P C o n te x t A ctiva tio n - P D P C o n te x t D e a ctiva tion (las t)- P a cke t D a ta D e ta ch
- P D P C o n te x t A ctiva tio n R e je c te d
- P D P C o n te x t A ctiva tio n- P D P C o n te x t M od if ica tio n- P D P C o n te x t D e a ctiva tion
48 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
GTP - GPRS Tunnelling Protocol
DOCUMENTTYPETypeUnitOrDepartmentHereTypeYourNameHere TypeDateHere
User
packetUserPacket
Userpacket
Userpacket
GGSN
The stream of containersforming a tunnel.
Userpacket
3G-
SGSN
RNC
The stream of containers
form a 'tunnel'
49 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
UE BS RNC 3G-SGSN1. PDP Context Deactivation Request
2. PDP Context Deactivation Accept
3. Bearer Assignment Request (Release)
4. Radio Link Release
5. Bearer Assignment Complete (Release)
De-activation of PDP ContextReleasing of bearer
50 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Communication Management
Network Application Intelligence
Connection
Service and customer
application control
• Subscriber's service profile- location information- billing of service- push control
- personalisation- etc...
• Security• Mobility• Charging information collection
End user application • Email• MO-MT SMS• etc...
52 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Collection of charging data
RNC
Billing Centre
Charging Gateway
HLR
3GSGSN
3GMSC
GGSN
CDR (Charging Data Records) are sent to
the Billing Centre
53 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Handling emergency calls
RNC
HLR
3GMSC
The MSC defines if calls are allowed and where they should be routed to, based upon
location
3GSGSN GGSN
To different regional call
centres
No checking is done (also SIM does not
need to be active) to make emergency call
Location Based Server
If location based services are used,
then the emergency services can gain
accurate information on the subscriber's
location
54 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
3G/UMTS Traffic Management
Review Questions
55 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Review
1. In which network elements is security related information located?
a. USIM
b. RNC
c. AuC
d. SGSN
e. Node B
f. non of all above
56 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Review
2. Which parameter identifies the subscriber?
a. IMSI
b. IMEI
c. MCC
d. P-TMSI
e. TMSI
f. PIN
57 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Review
3. Which location information is known in the UE?
a. LA
b. RA
c. URA
d. 3G-MSC supply area
e. 3G-SGSN supply area
58 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
4. Which of the following is/are characteristic(s) of a UMTS bearer?
a. Variable data rate
b. Transparent through the RAN
c. Different lengths of delay
d. Asymmetric connection
e. None of the above
Review
59 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Used by the CN CS Domain
______________________
Used by the CN PS Domain
______________________
Used in the RNC
______________________
What otherinformation is kept?
__________________
__________________
__________________
__________________
ReviewUTRAN Registration Areas
Routing Areas
Location Areas
Cell ID
Positioning Service
60 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
6. Which of the following sentences about location update is NOT true?
a. IMSI attach is always made when the terminal is switched on.
b. Location/routing Area update takes place when a subscriber moves between LAs and/or RAs.
c. Periodic location updates are not used in UMTS.
d. None of the above.
7. TRUE or FALSEThe URA (UTRAN Registration Area) is used by the core network to keep track of subscribers in the network.
Review
61 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Review
7. Which of the following sentences about the RRC (Radio Resource Connection) is true?
a. It is only used in GPRS networks.b. It is a collection of radio access bearers over the air interface.c. It is a wireless protocol.d. All of the above.
8. The operation of requesting a subscriber to contact the network is called:a. IMSI attachb. Location updatec. Pagingd. Bearer allocation9
8
62 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
9. Which of the following sentences best describes authentication:a. Security of the user information on the air interfaceb. IMSI and IMEI checkingc. Supplementary service status checking (by the subscriber)d. A process used by the GGSN to determine firewall access
10. In UMTS a terminal has two states, idle and connected. In the following list, identify which state the mobile is in.
a. The mobile is in _______________mode when it is camping on a cell.
b. The mobile is in _______________mode when it does not have any connection state.
c. If data is being transferred from the packet core to the mobile, then the state is _______________.
Review
Idle
Idle
Connected
10
11
63 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
Review
12. During a PDP context activation process, which information is transmitted from the UE to the SGSN?a. APNb. PDPc. GGSN addressd. DNS addresse. TID
64 © NOKIA CTXX 5324en 4.0.PPT/ 17.12.2002 / Björn Wigforss
12. When a subscriber triggers an event in the network (e.g. a call), a CDR is generated. What is a CDR?
a. Charging data record which is sent to a Billing/Charging Centreb. Caller digital reset to the MSCc. Customer data receipt, which is a bill that is sent to the customer d. All of the above
13. True or False SMS messages can be sent via the SGSN.
Review