UMTS Services. Part I: Basics Bearer services and teleservices Supplementary services Multimedia services QoS architecture

Transcription

1 UMTS Services Part I: Basics Bearer services and teleservices Supplementary services Multimedia services QoS architecture

2 References Kaaranen, et al, Ch. 7 Walke, et al, ch. 10 3GPP TS : service aspects, service principles 3GPP TS : services & service capabilities 3GPP TS : supplementary services 3GPP TR : QoS concept 2

3 Basic telecommunication services Teleservices Bearer services TE TAF MT PLMN possible transit network Terminating network TE UE UE: User Equipment MT: Mobile Termination TE: Terminal Equipment TAF: Teminal Adaption Function The communication link between the access points may consist of a PLMN, one or more transit networks and a terminating network Source: 3GPP TS , ch. 4 The networks between the two access points typically use different means for bearer control 3

4 Basic telecommunication services Teleservices Bearer services TE TAF MT PLMN possible transit network Terminating network TE UE Bearer UE: User Equipment services MT: Mobile Termination TE: Terminal Equipment TAF: Teminal Adaption Function providing the capability of transmission of information between access points low layer functions only Teleservices providing the complete capability, including terminal equipment functions, for communication between users (according to protocols established by agreement between network operators) a set of upper layer capabilities utilising the lower layer capabilities (bearer services) Examples: voice call, FAX, emergency call, SMS (point to point and cell broadcast) and Internet access Source: 3GPP TS , ch. 4 & 6 4

5 Bearer Services Bearer services capability of transmission of information between access points low layer functions only PS and CS domains provide a specific set of bearer capabilities Bearer services are characterised by a set of end-to-end characteristics with requirements on QoS (networks and terminal) The characteristics and requirements shall cover major network scenarios, i.e. the cases when the terminating network is PSTN, ISDN, GSM, IP networks/lans, X.25 and a PLMN Requirements on bearer services: Information transfer characteristics describe the networks transfer capabilities for transferring user data between two or more access points Information quality characteristics describe the quality of the user information transferred between two or more access points Source: 3GPP TS , ch. 5 5

6 Bearer Services Information transfer characteristics Traffic types guaranteed/constant bit rate non-guaranteed/dynamically variable bit rate real-time dynamically variable bit rate with minimum guaranteed bit rate Traffic characteristics point-to-point (unidirectional, bidirectional (symmetric/asymmetric)) unidirectional point-to-multipoint (multicast, broadcast) Information quality characteristics data rate bit error rate maximum transfer delay delay variation Source: 3GPP TS , ch. 5 6

7 Bearer Services Supported End User QoS 7 Summary of applications in terms of requirements Acceptable error rate Error tolerant Error intolerant Conversational voice and video Telnet, interactive games Voice messaging E-commerce, WWW browsing, Streaming audio and video FTP, still image, paging Fax arrival notification Conversational (delay <<1 sec) Interactive (delay approx.1 sec) Streaming (delay <10 sec) Background (delay >10 sec) Delays requirements

8 Bearer Services End User Performance Expectations 8 Conversational/real-time services Medium Application Degree of symmetry Data rate Key performance parameters and target values Audio Conversational voice Two-way 4-25 kb/s Video Videophone Two-way kb/s Data Telemetry -two-way control Two-way <28.8 kb/s End-to-end One-way Delay <150 msec preferred <400 msec limit Note 1 Delay Variatio n within a call < 1 msec Information loss < 3% FER < 150 msec < 1% FER preferred <400 msec limit Lip-synch : < 100 msec < 250 msec N.A Zero Data Interactive games Two-way < 1 KB < 250 msec N.A Zero Data Telnet Two-way (asymmetric) < 1 KB < 250 msec N.A Zero Note 1: The overall one way delay in the mobile network (from UE to PLMN border) is approximately 100msec.

9 9 Bearer Services End User Performance Expectations Interactive services Medium Application Degree of symmetry Data rate Key performance parameters and target values One-way Delay Delay Variation Information loss Audio Voice messaging Primarily one-way 4-13 kb/s < 1 sec for playback < 2 sec for record < 1 msec < 3% FER Data Data Data Web browsing -HTML Transaction services high priority e.g. e- commerce, ATM (server access) Primarily oneway < 4 sec /page N.A Zero Two-way < 4 sec N.A Zero Primarily One-way < 4 sec N.A Zero

10 Bearer Services End User Performance Expectations 10 Streaming services Medium Application Degree of symmetry Data rate Key performance parameters and target values One-way Delay Delay Variation Information loss Audio High quality streaming audio Primarily oneway kb/s < 10 sec < 1 msec < 1% FER Video One-way One-way kb/s < 10 sec < 1% FER Data Bulk data transfer/ retrieval Primarily oneway < 10 sec N.A Zero Data Still image One-way < 10 sec N.A Zero Data Telemetry - monitoring One-way <28.8 kb/s < 10 sec N.A Zero

11 Bandwidth of UMTS Services End-to-end packet switched traffic (peak channel rates) 2.3 Mbit/s for the up- and downlink (6*384 kbps in early releases) Average aggregate throughput of a cell (for both up and downlink) (Source: H. Menkes, Lucent Technologies, WirelessWeb, Aug. 2002) Assumptions: interference, realistic RF conditions including fading, random traffic, random distribution of mobiles kbps per cell (compare to 95 kbps for GPRS cell) worse figures for individual TCP traffic 11

12 Supplementary Services Supplementary services modify or supplement a basic telecommunication service offered to user together or in association with a basic telecommunication service Examples of supplementary services: Call forwarding (unconditional, conditional) Call barring (restrict incoming/outgoing calls; subscriber- or operatorcontrolled) Number identification Call waiting and call hold Multi-party call Closed user groups (restricted access rights) Advice of charge... Source: 3GPP TS , ch. 4; see 3GPP TS for details 12

13 Multimedia Services UMTS supports multimedia services and provides the necessary capabilities to support these services Definition: multimedia service combines two or more media components (e.g. voice, audio, data, video, pictures) within one call may involve several parties and connections (different parties may provide different media components) => flexibility required to add and delete resources and/or parties Multimedia service types Interactive services conversational messaging retrieval services Distribution services providing user presentation control not providing user presentation control (e.g. traditional TV) 13

14 Multimedia Services Interactive Services Conversational services real-time (no store and forward), usually bi-directional where low end to end delays (< 100 ms) and a high degree of synchronisation between media components (implying low delay variation) Examples: Video telephony, video conferencing Messaging services user to user communication via store and forward units (mailbox or message handling devices). Examples: combined voice and text, audio and high resolution images. Retrieval services enable a user to retrieve information stored in information centers start of information retrieval is under control of the user each information center accessed may provide a different media component, e.g. high resolution images, audio and general archival information 14

15 Multimedia Services Distribution Services 15 Types of distribution services providing user presentation control and not providing user presentation control Distribution services without user control broadcast services where information is supplied by a central source and the user can access the flow of information without any ability to control the start or order of presentation, e.g. television or audio broadcast services Distribution services with user control broadcast services where information is broadcast as a repetitive sequence the ability to access sequence numbering allocated to frames of information => enables the user (or the user s terminal) to control the start and order of presentation of information 3GPP specifications shall support single media services (e.g. telephony) and multimedia services (e.g. video telephony) all calls may become multimedia calls and there shall be no need to signal, in advance, any requirement for any number of multimedia components however, it shall be possible to reserve resources in advance to enable all required media components to be available

16 Quality of Service: Basics QoS attributes: data rate error rate (bit, frame) delay delay variation How can the system ensure certain QoS attributes? reservation of dedicated resources for a connection (e.g. CS voice, RSVP) priorization of the use of a shared resource by a connection (e.g. DiffServ) Basic functions to provide QoS admission control (possibly including resource reservation) traffic classification (policing user plane) traffic conditioning (traffic shaping user plane) overload control 16

17 17 Bearer Services Recap Source: 3GPP TS UMTS TE MT UTRAN CN Iu EDGE NODE End-to-End Service CN Gateway TE TE/MT Local Bearer Service UMTS Bearer Service External Bearer Service Radio Access Bearer Service CN Bearer Service Radio Bearer Service Iu Bearer Service Backbone Bearer Service UTRA FDD/TDD Service Physical Bearer Service

18 QoS Architecture for UMTS Bearer Services (user plane) TE MT UTRAN CN EDGE Gateway Ext. Netw. Class if Class if Cond. Cond. Cond. Mapper Mapper Mapper Local BS Resource Resource Resource Resource Resource Resource External BS UTRA phys. BS data flow with indication of direction Iu network service BB network service Classification function (Class.) assigns user data units received from the external bearer service to the appropriate UMTS bearer service according to the QoS requirements of each user data unit Traffic conditioner (Cond.) MT: provides conformance of the uplink user data traffic with the QoS attributes of the UMTS bearer service Gateway: provide conformance of the downlink user data traffic with the QoS attributes of the UMTS bearer service Mapping function marks each data unit with the specific QoS indication related to the bearer service performing the transfer of the data unit Resource managers distribute its resources between all bearer services requesting transfer of data units on these resources Sources: 3GPP TS , TR

19 QoS Architecture (control plane) 19 QoS management functions to establish and modify a UMTS bearer service signalling/negotiation with the UMTS external services establishment or modification of all UMTS internal services TE Local Service Transl. MT UMTS BS Adm./Cap. UTRAN Adm./Cap. RAB CN EDGE Adm./Cap. UMTS BS Subscr. Gateway Adm./Cap. UMTS BS Transl. Ext. Netw. Ext. Service Local BS Radio BS Radio BS Iu BS Adm. Iu BS Contr CN BS CN BS Ext. BS UTRA ph. BS M UTRA ph. BS M Iu NS Iu NS BB NS BB NS protocol interface service primitive interface Source: 3GPP TS , TR

20 QoS Architecture (control plane) 20 convertion between external service signalling and internal service primitives and attributes Check if the network entity supports the requested service and the availability of required resources convertion between external service signalling and internal service primitives and attributes signalling between each other and with external instances to establish or modify a UMTS bearer service and ext. services verification of administrative rights for using the service TE Local Service Transl. MT UMTS BS Adm./Cap. UTRAN Adm./Cap. RAB Adm./Cap. CN EDGE UMTS BS Subscr. Gateway Adm./Cap. UMTS BS Transl. Ext. Netw. Ext. Service Local BS Radio BS Radio BS Iu BS Adm. Iu BS Contr CN BS CN BS Ext. BS UTRA ph. BS M UTRA ph. BS M Iu NS Iu NS BB NS BB NS provision of bearer services with the required attributes service primitive interface protocol interface translation of RAB service attributes into radio bearer service andiubearer service attributes

21 21 QoS Parameters UMTS Bearer Service Attributes Traffic class [ conversational, streaming, interactive, background ] Maximum bitrate [kbps] Guaranteed bitrate [kbps] Delivery order [y/n] Maximum SDU size [bits] SDU format information [bits] (needed for efficient RLC TM operation) Error rate [erroneous SDUs, bit errors] Transfer delay [s] Traffic handling priority Allocation/Retention Priority Similar QoS attributes are used for Radio Access Bearer

22 QoS Parameters 22 UMTS bearer attributes defined for each bearer class Traffic class Conversational class Streaming class Interactive class Background class Maximum bitrate X X X X Delivery order X X X X Maximum SDU size SDU format information X X X X Reliability X X X X Transfer delay X X Guaranteed bit rate Traffic handling priority X X X Allocation/ Retention priority X X X X Source: 3GPP TR