0
UMTS ... …  3G Technology and Concepts
GSM/GPRS network architecture GSM/GPRS core network Radio access network BSS database IP Backbone Internet PSTN, ISDN BTS ...
3GPP Rel.’99 network architecture Core network (GSM/GPRS-based) Radio access network UTRAN UE Iu CS Iur Iub Uu Gn Iu PS da...
3GPP Rel.’99 network architecture Radio access network UTRAN UE Iur Iub Uu BS BS RNC RNC Iub 2G => 3G  MS =>  UE  (User Eq...
3GPP Rel.’99 network architecture Core network (GSM/GPRS-based) Iu CS Gn Iu PS IP Backbone Internet PSTN MSC VLR SGSN GMSC...
3GPP Rel.4 network architecture Circuit Switched (CS)  core network UTRAN (UMTS Terrestrial Radio Access Network) PSTN MSC...
3GPP Rel.4 network architecture Circuit Switched (CS)  core network PSTN MSC Server PS core as in Rel.’99 GMSC Server SGW ...
3GPP Rel.5 network architecture CS core PSTN SGSN GGSN MGW Internet HSS IMS (IP Multimedia System) PS core UTRAN (UMTS Ter...
3GPP Rel.5 network architecture CS core PSTN SGSN GGSN Internet / other IMS HSS PS core The IMS can establish multimedia s...
UMTS bearer service architecture TE MT UTRAN CN Iu  edge node TE CN  gateway End-to-end service UMTS bearer service Radio ...
What is a bearer? <ul><li>Bearer:  a bearer capability of defined capacity, delay and bit error rate, etc. (as defined in ...
UMTS QoS (service) classes Conversational Streaming Interactive Background low delay low delay variation video  telephony/...
Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>speech (using  AMR = Adaptive Mult...
Adaptive Multi-Rate coding kbit/s 12.2 (= GSM EFR) 10.2 7.95 7.40 (= US TDMA) 6.70 (= PDC EFR) 5.90 5.15 4.75 Adaptive   <...
Transcoding  UE MSC GMSC User B TC Transcoder (AMR/PCM) should be located as far as possible to the right (transmission ca...
Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>video streaming </li></ul><ul><li>...
Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>web browsing </li></ul><ul><li>int...
Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>SMS (Short Message Service) and ot...
UMTS protocols <ul><li>Different protocol stacks for  user  and  control  plane </li></ul><ul><li>User plane (for transpor...
Data streams RLC MAC Phys. UE  UTRAN  3G MSC  GMSC U u I u G n User plane protocol stacks (CS domain) RLC MAC Phys. WCDMA ...
User plane protocol stacks (PS domain) PDCP RLC GTP UDP IP GTP UDP IP IP IP GTP UDP PDCP RLC MAC Phys. MAC Phys. AAL5 ATM ...
Uu (air, radio) interface protocols PHY MAC RLC RRC Signalling  radio bearers (User plane)  radio bearers e.g. MM, CC, SM ...
Main tasks of Uu interface protocols <ul><li>MAC (Medium Access Control):  </li></ul><ul><ul><li>Mapping between logical a...
Main tasks of RRC protocol Over the air interface, Radio Resource Control (RRC) messages carry all the relevant informatio...
General protocol model for UTRAN Radio Network Layer Transport Network Layer Control Plane User Plane Transport Netw. Cont...
Control Plane   (Iub, Iur and Iu interfaces) Radio Network Layer:   application protocols  (NBAP, RNSAP and RANAP) are use...
User Plane   (Iub, Iur and Iu interfaces) <ul><li>The User Plane is employed for transport of </li></ul><ul><ul><li>user i...
Protocol structure at Iub interface Radio Network Layer Transport Network Layer Control Plane Transport Netw. Control Plan...
Control Plane Transport Netw. Control Plane RNSAP Transport Netw. User Plane Transport Netw. User Plane Q.2630.1 Convergen...
Radio Network Layer Transport Network Layer Control Plane User Plane Transport Netw. Control Plane RANAP Transport Netw. U...
Radio Network Layer Transport Network Layer Control Plane User Plane Transport Netw. Control Plane RANAP Transport Netw. U...
Application protocols in UTRAN <ul><li>Iub interface (between RNC and base station) </li></ul><ul><li>NBAP (Node B Applica...
Serving RNC and Drift RNC in UTRAN Core network Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Concept needed for: Soft handove...
Serving RNS (SRNS) Relocation RNS = Radio Network Sub-system =  RNC + all base stations controlled by this RNC SRNS Reloca...
SRNS Relocation (cont.) Core network Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Iu SRNC SRNC provides:  1) connection to co...
Soft handover concept Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Leg 1 Leg 3 Signal combining point is in SRNC  (downlink: ...
Micro- / macrodiversity combining Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Macrodiversity combining point  in SRNC Core n...
Micro- / macrodiversity combining Microdiversity combining:   multipath signal components are processed in Rake “fingers” ...
Radio Access Bearer (RAB) establishment RAB assignment request RAB assignment complete RAB is configured to be used over e...
Signalling between UE and core network UE BS RNC MSC  or SGSN NAS signalling messages  (NAS = Non Access Stratum = “not re...
Security in UMTS GSM UMTS SIM authentication  (PIN code) User authentication Ciphering (air interface) Signalling data int...
Security in digital networks: terminology <ul><li>Authentication: </li></ul><ul><ul><li>SIM authentication   (PIN code) </...
Authentication <ul><li>Authentication :   Procedure of verifying the authenticity of an entity (user, terminal, network, n...
Integrity <ul><li>Data integrity :   The property that data has not been altered in an unauthorised manner.  </li></ul><ul...
Signalling integrity protection in UMTS Signalling message Algorithm f 9 MAC-I Integrity Key (IK) and other keys/parameter...
Confidentiality Confidentiality :   The property that information is not made available to unauthorised individuals, entit...
Example 1: ciphering (encryption) BS MS UE BTS BSC RNC SGSN Core Network Air interface GPRS UMTS MS BTS BSC Core Network G...
Network domain security Circuit switched network  =>  quite good IP-based network (Internet)  =>  rather poor at present (...
WCDMA Technology  …  just some basic issues
RLC RLC Logical / Transport / Physical channels MAC FP Phy FP UE Base station RNC AAL 2 MAC AAL 2 Phy  Logical channels Ph...
Logical / Transport channels CCCH DCCH PCH DCH DSCH FACH BCH DCH CPCH RACH DCCH CTCH CCCH BCCH PCCH Uplink Downlink DTCH D...
Transport / Physical channels PCH DCH DSCH FACH BCH DCH CPCH RACH PRACH PCPCH SCCPCH PCCPCH DPDCH DPCCH SCH CPICH AICH PIC...
Physical channels in WCDMA <ul><li>Bit sequences from different physical channels are  </li></ul><ul><ul><li>multiplied wi...
DPCH structure in downlink QPSK modulation,  time multiplexed  data and control information: (DPCH = Dedicated Physical Ch...
DPDCH / DPCCH structure in uplink (Dedicated Physical Data/Control Channel) Dual-channel QPSK modulation: Data Pilot TFCI ...
Spreading in WCDMA Channel data Channelization code Scrambling code Channel bit rate Chip rate Chip rate Usage of code Upl...
Spreading in WCDMA Chip rate = SF  x  channel bit rate Chip rate after spreading = 3.84 Mchips/s Uplink:  DPCCH  SF = 256,...
Uplink DPDCH bit rates 256 128 64 32 16 8 4 SF Channel bit rate  (kb/s) User data rate  (kb/s) 15 30 60 120 240 480 approx...
Downlink DPDCH bit rates 256 128 64 32 16 8 4 SF Channel bit rate  (kb/s) User data rate  (kb/s) 15 30 60 120 240 480 appr...
User data rate vs. channel bit rate  Channel bit rate  (kb/s) User data rate  (kb/s) Channel coding Interleaving Bit rate ...
Services for 3G (and partly 2G) <ul><li>terminology </li></ul><ul><li>basic concepts </li></ul>
New service concept End user End user Carrier provider Service provider Service provider Content provider Content provider...
OSA is being standardised, so that services provided by different service/content providers can be created and seamlessly ...
CAMEL (Customised Applications for Mobile network Enhanced Logic)  is a set of “IN” type functions and procedures that mak...
Circuit switched call-related IN procedures CAMEL Phase 1 1.  Call control proceeds up to MSC SSP MSC SCP in home network ...
CAMEL Phase 2 Non -call-related procedures possible 1.  Call control proceeds as normal 2.  Call control is interrupted  3...
Virtual Home Environment (VHE) Same subscriber profile & charging/numbering information can be utilised in any UMTS networ...
Supporting technologies and services  Positioning SMS USSD MMS LCS SAT USAT MExE WAP Location UE Transport & Content i-Mod...
Location (based) services (LCS)  -  may or may not use UE positioning techniques -  general LCS architecture in UMTS: UE P...
Location (based) services (cont.)  <ul><li>GMLC  =  Gateway Mobile Location Center  </li></ul><ul><ul><li>receives service...
Positioning methods  BS BS BS UE LMU Cell ID based location information -  no expensive positioning solutions required -  ...
SAT (= USAT in 3G)  SAT (SIM Application Toolkit) is a set of standardized functions for communication between SIM and ME ...
MExE  Mobile Execution Environment (MExE) provides standardized application execution environments for UE, defined in clas...
SMS vs. USSD  SMS  =  Short Message Service USSD  =  Unstructured Supplementary Services Data  <ul><li>SMS </li></ul><ul><...
MMS  <ul><li>MMS  =  Multimedia Messaging System  </li></ul><ul><li>Offers the possibility to send messages to/from MMS ca...
WAP (Wireless Application Protocol)  Transports WML (Wireless Markup Language) information between terminal and WAP Gatewa...
Service interaction example  3G subscriber is hungry and asks for a list of nearby located restaurants (from appropriate “...
Example, Step 1  By use of his/her WAP browser in the UE, user contacts (via WAP Gateway) the “Internet Server” containing...
Example, Step 2  The 2G/3G network retrieves subscription information (e.g. state of “prepaid” account) from the user’s CS...
Example, Step 3  “ Internet Server” acts as a “LCS client” and requests the 2G/3G network to investigate where the user is...
Example, Step 4  The “MExE compatible Internet Server” prepares the information according to the MExE capabilities of UE (...
Example, Step 5  Now the “local restaurants” information is downloaded to the user and displayed in the appropriate form. ...
Further information on 3G systems and services  Links:  see slides Books:  Kaaranen et al.,  UMTS Networks: Architecture, ...
Upcoming SlideShare
Loading in...5
×

Umts

4,655

Published on

Published in: Technology, Business
1 Comment
7 Likes
Statistics
Notes
  • thnx, very useful
       Reply 
    Are you sure you want to  Yes  No
    Your message goes here
No Downloads
Views
Total Views
4,655
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
531
Comments
1
Likes
7
Embeds 0
No embeds

No notes for slide

Transcript of "Umts"

  1. 1. UMTS ... … 3G Technology and Concepts
  2. 2. GSM/GPRS network architecture GSM/GPRS core network Radio access network BSS database IP Backbone Internet PSTN, ISDN BTS BTS BSC MSC VLR SGSN GMSC HLR AuC EIR GGSN MS PCU
  3. 3. 3GPP Rel.’99 network architecture Core network (GSM/GPRS-based) Radio access network UTRAN UE Iu CS Iur Iub Uu Gn Iu PS database IP Backbone Internet PSTN BS BS RNC RNC MSC VLR SGSN GMSC HLR AuC EIR GGSN Iub
  4. 4. 3GPP Rel.’99 network architecture Radio access network UTRAN UE Iur Iub Uu BS BS RNC RNC Iub 2G => 3G MS => UE (User Equipment), often also called (user) terminal New air (radio) interface based on WCDMA access technology New RAN architecture ( Iur interface is available for soft handover, BSC => RNC )
  5. 5. 3GPP Rel.’99 network architecture Core network (GSM/GPRS-based) Iu CS Gn Iu PS IP Backbone Internet PSTN MSC VLR SGSN GMSC HLR AuC EIR GGSN Changes in the core network: MSC is upgraded to 3G MSC SGSN is upgraded to 3G SGSN GMSC and GGSN remain the same AuC is upgraded (more security features in 3G)
  6. 6. 3GPP Rel.4 network architecture Circuit Switched (CS) core network UTRAN (UMTS Terrestrial Radio Access Network) PSTN MSC Server New option in Rel.4: GERAN (GSM and EDGE Radio Access Network) PS core as in Rel.’99 GMSC Server SGW MGW SGW MGW
  7. 7. 3GPP Rel.4 network architecture Circuit Switched (CS) core network PSTN MSC Server PS core as in Rel.’99 GMSC Server SGW MGW SGW MGW MSC Server takes care of call control signalling The user connections are set up via MGW (Media GateWay) “ Lower layer” protocol conversion in SGW (Signalling GateWay) RANAP / ISUP SS7 MTP IP Sigtran
  8. 8. 3GPP Rel.5 network architecture CS core PSTN SGSN GGSN MGW Internet HSS IMS (IP Multimedia System) PS core UTRAN (UMTS Terrestrial Radio Access Network) GERAN (GSM and EDGE Radio Access Network) New core network part:
  9. 9. 3GPP Rel.5 network architecture CS core PSTN SGSN GGSN Internet / other IMS HSS PS core The IMS can establish multimedia sessions (using IP transport) via PS core between UE and Internet (or another IMS) Call/session control using SIP (Session Initiating Protocol) Interworking with the PSTN may be required for some time ... IMS (IP Multimedia System) MGW
  10. 10. UMTS bearer service architecture TE MT UTRAN CN Iu edge node TE CN gateway End-to-end service UMTS bearer service Radio access bearer service CN b.s. Local b.s. Ext. b.s. Radio b.s. Iu b.s. Backbone Radio Access Bearer Radio Bearer UE Core network
  11. 11. What is a bearer? <ul><li>Bearer: a bearer capability of defined capacity, delay and bit error rate, etc. (as defined in 3GPP specs.) </li></ul><ul><li>Bearer is a flexible concept designating some kind of ”bit pipe” </li></ul><ul><ul><li>at a certain network level (see previous slide) </li></ul></ul><ul><ul><li>between certain network entities </li></ul></ul><ul><ul><li>with certain QoS attributes, capacity, and traffic </li></ul></ul><ul><ul><li>flow characteristics </li></ul></ul><ul><li>Four UMTS QoS Classes </li></ul><ul><ul><li>conversational, streaming , interactive, background </li></ul></ul>
  12. 12. UMTS QoS (service) classes Conversational Streaming Interactive Background low delay low delay variation video telephony/ conferencing speech video streaming audio streaming low round-trip delay www applications delay is not critical store-and- forward applications (e-mail, SMS) file transfer reasonably low delay basic applications basic QoS requirements
  13. 13. Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>speech (using AMR = Adaptive Multi-Rate speech coding) </li></ul><ul><li>video telephony / conferencing: </li></ul>ITU-T Rec. H.324 (over circuit switched connections) ITU-T Rec. H.323 or IETF SIP (over packet switched connections) <ul><li>low delay (< 400 ms) and low delay variation </li></ul><ul><li>BER requirements not so stringent </li></ul><ul><li>in the radio network => real-time (RT) connections </li></ul>
  14. 14. Adaptive Multi-Rate coding kbit/s 12.2 (= GSM EFR) 10.2 7.95 7.40 (= US TDMA) 6.70 (= PDC EFR) 5.90 5.15 4.75 Adaptive <=> During the call, the AMR bit rate can be changed, using the values at the right EFR = Enhanced Full Rate Codec negotiation between transcoders <=>
  15. 15. Transcoding UE MSC GMSC User B TC Transcoder (AMR/PCM) should be located as far as possible to the right (transmission capacity savings) TC Transcoding should be avoided altogether (better signal quality) TFO = Tandem Free Operation (2G) TrFO = Transcoder Free Operation (3G) (possible only if same coding is used at both ends of connection) (e.g. in PSTN)
  16. 16. Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>video streaming </li></ul><ul><li>audio streaming </li></ul><ul><li>reasonably low delay and delay variation </li></ul><ul><li>BER requirements quite stringent </li></ul><ul><li>traffic management important (variable bit rate) </li></ul><ul><li>in the radio network => real-time (RT) connections </li></ul>UE Source video or audio information is buffered in the UE, large delay => buffer is running out of content! Buffer
  17. 17. Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>web browsing </li></ul><ul><li>interactive games </li></ul><ul><li>location-based services (LCS) </li></ul><ul><li>low round-trip delay (< seconds) </li></ul><ul><li>delay variation is not important </li></ul><ul><li>BER requirements stringent </li></ul><ul><li>in the radio network => non-real-time (NRT) connections </li></ul>
  18. 18. Four UMTS QoS (service) classes Conversational Streaming Interactive Background <ul><li>SMS (Short Message Service) and other more advanced </li></ul><ul><li>messaging services (EMS, MMS) </li></ul><ul><li>e-mail notification, e-mail download </li></ul><ul><li>file transfer </li></ul><ul><li>delay / delay variation is not an important issue </li></ul><ul><li>BER requirements stringent </li></ul><ul><li>in the radio network => non-real-time (NRT) connections </li></ul>
  19. 19. UMTS protocols <ul><li>Different protocol stacks for user and control plane </li></ul><ul><li>User plane (for transport of user data): </li></ul><ul><ul><li>Circuit switched domain: data within ”bit pipes” </li></ul></ul><ul><ul><li>Packet switched domain: protocols for implementing various QoS or traffic engineering mechanisms </li></ul></ul><ul><li>Control plane (for signalling): </li></ul><ul><ul><li>Circuit switched domain: SS7 based (in core network) </li></ul></ul><ul><ul><li>Packet switched domain: IP based (in core network) </li></ul></ul><ul><ul><li>Radio access network: UTRAN protocols </li></ul></ul>
  20. 20. Data streams RLC MAC Phys. UE UTRAN 3G MSC GMSC U u I u G n User plane protocol stacks (CS domain) RLC MAC Phys. WCDMA TDM Frame Protocol (FP) AAL2 ATM Phys. AAL2 ATM Phys. TDM
  21. 21. User plane protocol stacks (PS domain) PDCP RLC GTP UDP IP GTP UDP IP IP IP GTP UDP PDCP RLC MAC Phys. MAC Phys. AAL5 ATM Phys. AAL5 ATM Phys. IP L2 L1 GTP UDP IP L2 L1 UE UTRAN SGSN GGSN U u I u G n WCDMA
  22. 22. Uu (air, radio) interface protocols PHY MAC RLC RRC Signalling radio bearers (User plane) radio bearers e.g. MM, CC, SM transparent to UTRAN Logical channels Transport channels PDCP L3 L2 L1
  23. 23. Main tasks of Uu interface protocols <ul><li>MAC (Medium Access Control): </li></ul><ul><ul><li>Mapping between logical and transport channels </li></ul></ul><ul><ul><li>Segmentation of data into transport blocks </li></ul></ul><ul><li>RLC (Radio Link Control): </li></ul><ul><ul><li>Segmentation and reassembly </li></ul></ul><ul><ul><li>Link control (flow & error control) </li></ul></ul><ul><ul><li>RLC is often a transparent layer </li></ul></ul><ul><li>PDCP (Packet Data Convergence Protocol): </li></ul><ul><ul><li>IP packet header compression (user plane only) </li></ul></ul>
  24. 24. Main tasks of RRC protocol Over the air interface, Radio Resource Control (RRC) messages carry all the relevant information required for setting up a Signalling Radio Bearer (during the lifetime of the RRC Connection) and setting up, modifying, and releasing Radio Bearers between UE and UTRAN (all being part of the RRC Connection). RRC also participates in the co-ordination of other Radio Resource Management (RRM) operations, such as measurements and handovers. In addition, RRC messages may carry in their payload higher layer signalling information (MM, CC or SM) that is not related to the air interface or UTRAN.
  25. 25. General protocol model for UTRAN Radio Network Layer Transport Network Layer Control Plane User Plane Transport Netw. Control Plane Application Protocol Data Stream(s) Signalling Bearer(s) Protocol Data Bearer(s) Transport Netw. User Plane Transport Netw. User Plane Signalling Bearer(s) Physical Layer
  26. 26. Control Plane (Iub, Iur and Iu interfaces) Radio Network Layer: application protocols (NBAP, RNSAP and RANAP) are used for the actual signalling between base stations, RNC and core network. Transport Network Layer: signalling bearer for the transport of application protocol messages is set up by O&M actions (i.e. on a permanent basis). Transport Network Control Plane A signalling bearer (set up by O&M actions) carries a protocol which is used only for the task of setting up data bearers (e.g. AAL 2 connections).
  27. 27. User Plane (Iub, Iur and Iu interfaces) <ul><li>The User Plane is employed for transport of </li></ul><ul><ul><li>user information (speech, video, IP packets ... ) </li></ul></ul><ul><ul><li>RRC signalling messages (Iub, Iur) </li></ul></ul><ul><ul><li>higher-layer protocol information at Iu interface </li></ul></ul><ul><li>(if not carried by RANAP). </li></ul><ul><li>User plane data is carried by data bearers which use AAL 5 in case of Iu PS and AAL 2 in all other cases. </li></ul><ul><li>User data streams are packed in frame protocols (FP) which are used for framing, error & flow control, and carrying of parallel data flows that form the user data signal (e.g. AMR encoded speech). </li></ul>
  28. 28. Protocol structure at Iub interface Radio Network Layer Transport Network Layer Control Plane Transport Netw. Control Plane NBAP Transport Netw. User Plane Transport Netw. User Plane Q.2630.1 Convergence Protocols AAL 5 Conv. Pr. AAL 5 AAL 2 ATM Physical Layer RRC Data RLC MAC Frame Protocol
  29. 29. Control Plane Transport Netw. Control Plane RNSAP Transport Netw. User Plane Transport Netw. User Plane Q.2630.1 Convergence Protocols AAL 5 Conv. Pr. AAL 5 AAL 2 ATM Physical Layer Protocol structure at Iur interface Radio Network Layer Transport Network Layer RRC Data RLC MAC Frame Protocol
  30. 30. Radio Network Layer Transport Network Layer Control Plane User Plane Transport Netw. Control Plane RANAP Transport Netw. User Plane Transport Netw. User Plane Q.2630.1 Convergence Protocols AAL 5 Conv. Pr. AAL 5 CS Channel Iu UP AAL 2 ATM Physical Layer Protocol structure at Iu CS interface
  31. 31. Radio Network Layer Transport Network Layer Control Plane User Plane Transport Netw. Control Plane RANAP Transport Netw. User Plane Convergence Protocols AAL 5 IP Application Protocol structure at Iu PS interface GTP UDP IP AAL 5 ATM Physical Layer Iu UP
  32. 32. Application protocols in UTRAN <ul><li>Iub interface (between RNC and base station) </li></ul><ul><li>NBAP (Node B Application Part) </li></ul><ul><li>Iur interface (between Serving RNC and Drift RNC) </li></ul><ul><li>RNSAP (Radio Network Subsystem Application Part) </li></ul><ul><ul><li>- Link management for inter-RNC soft handover </li></ul></ul><ul><li>Iu interface (between RNC and core network) </li></ul><ul><li>RANAP (Radio Access Network Application Part) </li></ul><ul><ul><li>Radio Access Bearer (RAB) management </li></ul></ul><ul><ul><li>SRNS Relocation </li></ul></ul><ul><ul><li>Transfer of higher-level signalling messages </li></ul></ul>
  33. 33. Serving RNC and Drift RNC in UTRAN Core network Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Concept needed for: Soft handover between base stations belonging to different RNCs
  34. 34. Serving RNS (SRNS) Relocation RNS = Radio Network Sub-system = RNC + all base stations controlled by this RNC SRNS Relocation means that the Serving RNC functionality is transferred from one RNC (the “old” SRNC) to another (the “new” SRNC, previously a DRNC) without changing the radio resources and without interrupting the user data flow. RANAP provides the signalling facilities over the two Iu interfaces involved (Iu interfaces to “old” and “new” SNRC) for performing SRNC Relocation in a co-ordinated manner.
  35. 35. SRNS Relocation (cont.) Core network Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Iu SRNC SRNC provides: 1) connection to core network 2) macrodiversity combining point
  36. 36. Soft handover concept Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Leg 1 Leg 3 Signal combining point is in SRNC (downlink: in UE) BS Leg 2 Legs 1 and 2: Iur interface is not needed Leg 3 is added: Iur interface is needed! Core network
  37. 37. Micro- / macrodiversity combining Iu Iur Iub Iub DRNC SRNC UE BS BS RNC RNC Macrodiversity combining point in SRNC Core network Rake receiver Multipath propagation Microdiversity combining point in base station (uplink)
  38. 38. Micro- / macrodiversity combining Microdiversity combining: multipath signal components are processed in Rake “fingers” and combined (= summed) using MRC (MRC = Maximum Ratio Combining) Macrodiversity combining: the same bit sequences (with different bit error positions) are combined at the SRNC (usually: selection combining). Hard handover: slow (a lot of signalling) Soft handover: fast selection in SRNC (uplink)
  39. 39. Radio Access Bearer (RAB) establishment RAB assignment request RAB assignment complete RAB is configured to be used over existing Radio Link(s) (RANAP signaling) UE BS RNC (RRC signaling) Core network
  40. 40. Signalling between UE and core network UE BS RNC MSC or SGSN NAS signalling messages (NAS = Non Access Stratum = “not related to UTRAN”) are sent transparently through UTRAN in the payload of RRC/RANAP protocol messages RRC RANAP
  41. 41. Security in UMTS GSM UMTS SIM authentication (PIN code) User authentication Ciphering (air interface) Signalling data integrity IP security (e.g. IPSEC) User authentication Network authentication USIM authentication (PIN code) Ciphering (air interface) KASUMI algorithm (known) UMTS: larger key lengths than in GSM
  42. 42. Security in digital networks: terminology <ul><li>Authentication: </li></ul><ul><ul><li>SIM authentication (PIN code) </li></ul></ul><ul><ul><li>user authentication (GSM, UMTS, DECT, TETRA) </li></ul></ul><ul><ul><li>network authentication (UMTS, TETRA) </li></ul></ul><ul><li>Integrity: </li></ul><ul><ul><li>signalling data integrity (UMTS) </li></ul></ul><ul><li>Confidentiality (  privacy): </li></ul><ul><ul><li>ciphering of signals over radio interface </li></ul></ul><ul><ul><li>hiding of user identifiers over radio interface </li></ul></ul><ul><ul><li>end-to-end encryption (offered by service provider) </li></ul></ul>
  43. 43. Authentication <ul><li>Authentication : Procedure of verifying the authenticity of an entity (user, terminal, network, network element). In other words, is the entity the one it claims to be? </li></ul><ul><ul><li>SIM authentication is local (network is not involved) </li></ul></ul><ul><ul><li>In GSM, only user is authenticated </li></ul></ul><ul><ul><li>In UMTS, both user and network are authenticated </li></ul></ul><ul><ul><li>User/network is authenticated at the beginning of each user-network transaction (e.g. location updating or connection set-up) and always before ciphering starts. </li></ul></ul>See Security in GSM for more details
  44. 44. Integrity <ul><li>Data integrity : The property that data has not been altered in an unauthorised manner. </li></ul><ul><ul><li>“ Man-in-the-middle” security attack, e.g. false BS </li></ul></ul><ul><ul><li>Data integrity checking is not done in GSM </li></ul></ul><ul><ul><li>In UMTS, signalling messages are appended with a 32 bit security field (MAC-I) at the terminal or RNC before transmission and checked at the receiving end </li></ul></ul><ul><ul><li>In UMTS, also volume of user data (not the user data itself) is integrity protected </li></ul></ul>
  45. 45. Signalling integrity protection in UMTS Signalling message Algorithm f 9 MAC-I Integrity Key (IK) and other keys/parameters UE RNC MAC-I generation MAC-I checking MAC-I generation MAC-I checking Both in terminal and RNC
  46. 46. Confidentiality Confidentiality : The property that information is not made available to unauthorised individuals, entities or processes. Example 1 : Ciphering (encryption) over the air interface Example 2 : Preventing unencrypted transmission of user ID information such as IMSI number over the air interface => Temporary Mobile Subscriber Identity (TMSI) is generated (at the end of each MM or CM transaction) and is used at the beginning of the next transaction instead of IMSI.
  47. 47. Example 1: ciphering (encryption) BS MS UE BTS BSC RNC SGSN Core Network Air interface GPRS UMTS MS BTS BSC Core Network GSM Both CS and PS information Signalling integrity protection
  48. 48. Network domain security Circuit switched network => quite good IP-based network (Internet) => rather poor at present (security mechanisms are developed by IETF, 3GPP...) Some security threats in IP-based network: Sniffing (electronic eavesdropping) Spoofing, session hijacking Denial of service (DoS), ”spamming” Confidentiality Integrity
  49. 49. WCDMA Technology … just some basic issues
  50. 50. RLC RLC Logical / Transport / Physical channels MAC FP Phy FP UE Base station RNC AAL 2 MAC AAL 2 Phy Logical channels Physical channels Transport channels : : WCDMA : :
  51. 51. Logical / Transport channels CCCH DCCH PCH DCH DSCH FACH BCH DCH CPCH RACH DCCH CTCH CCCH BCCH PCCH Uplink Downlink DTCH DTCH Logical channels Transport channels
  52. 52. Transport / Physical channels PCH DCH DSCH FACH BCH DCH CPCH RACH PRACH PCPCH SCCPCH PCCPCH DPDCH DPCCH SCH CPICH AICH PICH CSICH Physical channels Transport channels DPCH CD/CA-ICH Uplink Downlink PDSCH
  53. 53. Physical channels in WCDMA <ul><li>Bit sequences from different physical channels are </li></ul><ul><ul><li>multiplied with a channelization code (spreading) </li></ul></ul><ul><ul><li>multiplied with a scrambling code (scrambling) </li></ul></ul><ul><ul><li>multiplexed in code domain </li></ul></ul><ul><ul><li>modulated using QPSK. </li></ul></ul><ul><li>Downlink channels: conventional QPSK modulation </li></ul><ul><li>DPCH = Dedicated physical channel </li></ul><ul><li>Uplink channels: Dual-channel QPSK moduation </li></ul><ul><li>DPDCH = Dedicated physical data channel </li></ul><ul><li>DPCCH = Dedicated physical control channel </li></ul>
  54. 54. DPCH structure in downlink QPSK modulation, time multiplexed data and control information: (DPCH = Dedicated Physical Channel) TFCI Data TPC Data 10 ms radio frame 0 1 2 14 2560 chips Pilot
  55. 55. DPDCH / DPCCH structure in uplink (Dedicated Physical Data/Control Channel) Dual-channel QPSK modulation: Data Pilot TFCI FBI TPC DPDCH (I-branch) 10 ms radio frame (38400 chips) 0 1 2 14 2560 chips DPCCH (Q-branch)
  56. 56. Spreading in WCDMA Channel data Channelization code Scrambling code Channel bit rate Chip rate Chip rate Usage of code Uplink Downlink Channelization code Scrambling code User separation User separation Cell separation (always 3.84 million chips/s)
  57. 57. Spreading in WCDMA Chip rate = SF x channel bit rate Chip rate after spreading = 3.84 Mchips/s Uplink: DPCCH SF = 256, DPDCH SF = 4 - 256 Downlink: DPCH SF = 4 - 256 (512) Spreading factor (SF) is important in WCDMA One bit consists of 256 chips One bit consists of 4 chips
  58. 58. Uplink DPDCH bit rates 256 128 64 32 16 8 4 SF Channel bit rate (kb/s) User data rate (kb/s) 15 30 60 120 240 480 approx. 7.5 approx. 15 approx. 30 approx. 60 approx. 120 approx. 240 960 approx. 480
  59. 59. Downlink DPDCH bit rates 256 128 64 32 16 8 4 SF Channel bit rate (kb/s) User data rate (kb/s) 15 30 60 120 240 480 approx. 1-3 approx. 6-12 approx. 20-24 approx. 45 approx. 105 approx. 215 960 approx. 456 512 1920 approx. 936
  60. 60. User data rate vs. channel bit rate Channel bit rate (kb/s) User data rate (kb/s) Channel coding Interleaving Bit rate matching Interesting for user Important for system
  61. 61. Services for 3G (and partly 2G) <ul><li>terminology </li></ul><ul><li>basic concepts </li></ul>
  62. 62. New service concept End user End user Carrier provider Service provider Service provider Content provider Content provider all want to make profit
  63. 63. OSA is being standardised, so that services provided by different service/content providers can be created and seamlessly integrated into the 3G network (this is the meaning of “open” architecture) OSA (Open Services Architecture/Access) 3G network API API API Service Creation Environment (SCE) API = Application Programming Interface (Standardised) OSA means in practice:
  64. 64. CAMEL (Customised Applications for Mobile network Enhanced Logic) is a set of “IN” type functions and procedures that make operator-specific IN services available to subscribers who roam outside their home network. CAMEL = IN technology + global mobility CAMEL Service Environment (CSE) is a logical entity in the subscriber’s home network which processes IN related procedures CSE  SCP in home network CAMEL (2G & 3G)
  65. 65. Circuit switched call-related IN procedures CAMEL Phase 1 1. Call control proceeds up to MSC SSP MSC SCP in home network (CSE) 1. 2. 3. 4. 5. 2. Trigger activated in basic call state model at SSP 3. SSP requests information from CSE 4. CSE provides information 5. Call control continues Typical triggers: Calling number Called number Cell ID Protocol: CAP instead of MAP
  66. 66. CAMEL Phase 2 Non -call-related procedures possible 1. Call control proceeds as normal 2. Call control is interrupted 3. Call control resumes Typical application: In prepaid service: announcement ”your prepaid account is approaching zero” (e.g. for announcement) IN functionality is extended to include packet switched sessions... CAMEL Phase 3
  67. 67. Virtual Home Environment (VHE) Same subscriber profile & charging/numbering information can be utilised in any UMTS network Home PLMN Visited PLMN UE Certain subscriber profile Same subscriber profile
  68. 68. Supporting technologies and services Positioning SMS USSD MMS LCS SAT USAT MExE WAP Location UE Transport & Content i-Mode - many are already possible in 2G - will (perhaps) be extensively used in 3G
  69. 69. Location (based) services (LCS) - may or may not use UE positioning techniques - general LCS architecture in UMTS: UE PSTN Internet BS LMU RNC & SMLC MSC GMLC SGSN GGSN HLR/AuC/EIR GMSC LCS External Client
  70. 70. Location (based) services (cont.) <ul><li>GMLC = Gateway Mobile Location Center </li></ul><ul><ul><li>receives service requests from external LCS clients (or UE) and manages the location information </li></ul></ul><ul><li>SMLC = Serving Mobile Location Center </li></ul><ul><ul><li>assists in positioning of the UE (e.g. performs calculations based on measurement results), is usually integrated with RNC </li></ul></ul><ul><li>LCS client = typically any server requesting location </li></ul><ul><ul><li>information (to be able to provide the relevant location service to the user), may also be the UE </li></ul></ul>
  71. 71. Positioning methods BS BS BS UE LMU Cell ID based location information - no expensive positioning solutions required - inexpensive (and will therefore be widely used) E-OTD (2G), OTDOA (3G) - differential delays measured from which the position is calculated (in SMLC) Assisted GPS - greatest precision, GPS receiver in UE - network must “assist” in indoor environment SMLC
  72. 72. SAT (= USAT in 3G) SAT (SIM Application Toolkit) is a set of standardized functions for communication between SIM and ME SIM ME <ul><li>Applications (GSM 11.14): </li></ul><ul><li>profile download (ME tells SIM what it can do) </li></ul><ul><li>proactive SIM (display text from SIM to ME, send </li></ul><ul><li>short message, transfer info from ME to SIM,...) </li></ul><ul><li>call control by SIM </li></ul><ul><li>data download from network to SIM </li></ul>Download (e.g. Java applets) from server in network will be important in UMTS Interaction between ME and SIM
  73. 73. MExE Mobile Execution Environment (MExE) provides standardized application execution environments for UE, defined in classmarks: MExE Classmark 1 MExE Classmark 2 MExE Classmark 3 UE is WAP compatible (i.e. contains WAP browser) UE can execute PersonalJava applications (subset of J2SE) UE is J2ME compatible Standard Edition Micro Edition : see: www.mexeforum.org Evolution continues ...
  74. 74. SMS vs. USSD SMS = Short Message Service USSD = Unstructured Supplementary Services Data <ul><li>SMS </li></ul><ul><li>160 ASCII characters (max) </li></ul><ul><li>in all GSM terminals </li></ul><ul><li>store-and-forward service </li></ul><ul><li>(=> delay) </li></ul><ul><li>transport of messages </li></ul><ul><li>SMS transaction always </li></ul><ul><li>initiated by terminal </li></ul><ul><li>USSD </li></ul><ul><li>182 ASCII characters (max) </li></ul><ul><li>in all GSM terminals </li></ul><ul><li>connection oriented </li></ul><ul><li>transactions (small delay) </li></ul><ul><li>transport of technical data </li></ul><ul><li>terminal or application in </li></ul><ul><li>network initiates session </li></ul>very popular not much used (yet)
  75. 75. MMS <ul><li>MMS = Multimedia Messaging System </li></ul><ul><li>Offers the possibility to send messages to/from MMS capable handsets comprising a combination of </li></ul><ul><ul><ul><li>- text </li></ul></ul></ul><ul><ul><ul><li>- sounds </li></ul></ul></ul><ul><ul><ul><li>- images </li></ul></ul></ul><ul><ul><ul><li>- video </li></ul></ul></ul><ul><li>GPRS or 3G packet domain can be used for transport. </li></ul><ul><li>When combined with LCS information and IN (CAMEL) features, interesting new services can be implemented. </li></ul>
  76. 76. WAP (Wireless Application Protocol) Transports WML (Wireless Markup Language) information between terminal and WAP Gateway (using its own set of protocols) WAP Gateway UE 2G/3G network Internet Server WAP browser WML / HTML translation WML WAP protocols 2G/3G transport WML is a subset of XML e.g. WTP (similar functionality as HTTP) SMS, USSD, GPRS, 3G packet transport ... WML / HTML / XML content
  77. 77. Service interaction example 3G subscriber is hungry and asks for a list of nearby located restaurants (from appropriate “Internet Server”). Network scenario: UE 2G/3G network WAP Gateway Internet Server CAMEL (CSE) GMLC MExE See: Kaaranen et al: UMTS Networks
  78. 78. Example, Step 1 By use of his/her WAP browser in the UE, user contacts (via WAP Gateway) the “Internet Server” containing relevant information. UE 2G/3G network WAP Gateway Internet Server CAMEL (CSE) GMLC MExE WAP browser
  79. 79. Example, Step 2 The 2G/3G network retrieves subscription information (e.g. state of “prepaid” account) from the user’s CSE (Camel Service Environment). Charging info UE 2G/3G network WAP Gateway Internet Server CAMEL (CSE) GMLC MExE
  80. 80. Example, Step 3 “ Internet Server” acts as a “LCS client” and requests the 2G/3G network to investigate where the user is located. UE 2G/3G network WAP Gateway Internet Server CAMEL (CSE) GMLC MExE Where is UE located?
  81. 81. Example, Step 4 The “MExE compatible Internet Server” prepares the information according to the MExE capabilities of UE (in this case MExE Classmark 1: WAP). What can UE display? UE 2G/3G network WAP Gateway Internet Server CAMEL (CSE) GMLC MExE ? ?
  82. 82. Example, Step 5 Now the “local restaurants” information is downloaded to the user and displayed in the appropriate form. Restaurant 1 Restaurant 2 Restaurant 3 Restaurant 4 Menu on display: UE 2G/3G network WAP Gateway Internet Server CAMEL (CSE) GMLC MExE
  83. 83. Further information on 3G systems and services Links: see slides Books: Kaaranen et al., UMTS Networks: Architecture, Mobility and Services , Wiley, 2001, ISBN 0-471-48654-X Korhonen, Introduction to 3G Mobile Communications , Artech House, 2001, ISBN 1-58053-287-X Web material: e-learning course “Introduction to 3G” contains audio and flash animations (you need loudspeakers; access to course only within the HUT computer network) http://130.233.158.46/eopetus/intro3g/start.htm Required course material
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×