QoS Control and Resource Management in Heterogeneous Wireless Systems

Transcription

1 QoS Control and Resource Management in Heterogeneous Wireless Systems Fethi Filali Assistant Professor Institut Eurécom Novembre Project - QoS Seminar Telecom Paris, June 25, 2004

2 Agenda Heterogeneous wireless systems QoS in wireless networks QoS in UMTS Networks QoS in Networks Issues of QoS in Heterogeneous Systems Connecting UMTS and IPV6 Networks Radio Resource Management mechanism for UMTS networks QoS Management in Heterogeneous systems: Rhodos proposal Conclusion Fethi Filali 2

3 Heterogeneous wireless networks There exist many wireless communication networks which differ frequency bands requirements on mobility transmission speed and quality signaling protocols QoS architectures Examples: Static: wireless LANs (802.11), Bluetooth, UWB Pedestrian: DECT, PHS Vehicle: 2/3G cellular, pagers, broadcast TV/radio Fethi Filali 3

4 Future trends of mobile communications Mobility vehicle G cellular 4G cellular Intelligent Transport Systems High data rate High mobility System roaming Seamless connections to broadband networks pedestrian GSM Advanced wireless access HAPS static Wireless LAN Millimeterwave LAN 2G 3G 4G 5G 10k 2M 50M 156M 622M Data rate Fethi Filali 4

5 Heterogeneous networks, why? Fethi Filali 5

6 Heterogeneous networks, why? Due to roaming the network changed e.g. from indoor wireless LAN to outdoor cellular radio There is coverage from multiple wireless networks Possibility to select the most appropriate network for a given application, based on for example Service classification User requested QoS parameters Available network capacity (bandwidth, latency) Energy consumption needed Network operator contract Fethi Filali 6

7 Heterogeneous network architecture Goal : design a flexible and open architecture suitable for a variety of different wireless access technologies, for applications with different QoS demands, and different protocols Key requirements Different access technologies (Software Defined Radio) Heterogeneous network support (use combination of networks) Mobility management (seamless handover) Wireless system discovery Selection of efficient configuration Simple, scalable, low cost Energy efficient (always on) Secure Compatible/interoperable with existing and future work Quality of Service support (end-to-end, and local applicable) Fethi Filali 7

8 Agenda Heterogeneous wireless systems QoS in wireless networks QoS in UMTS Networks QoS in Networks Connecting UMTS and IPV6 Networks Radio Resource Management mechanism for UMTS networks QoS Management in Heterogeneous systems : Rhodos proposal Conclusion Fethi Filali 8

9 QoS in UMTS Networks UMTS TE MT UTRAN CN-lu CN EDGE Gateway NODE TE/Server End-to-End Service TE/MT Local Bearer Service UMTS Bearer UMTS Service Bearer Service External Bearer Service Radio Access Bearer Service CN Bearer Service Radio Bearer Service lu Bearer Service Backbone Bearer Service UTRA FDD/TDD Service Physical Bearer Service Fethi Filali 9

10 UMTS QoS Conversational Conversational Streaming Streaming Interactive Interactive Background Background low delay low delay variation reasonably low delay low round-trip delay basic QoS requirements delay is not critical speech video telephony/ conferencing video streaming audio streaming www applications basic applications store-andforward applications ( , SMS) file transfer Fethi Filali 10

11 Traffic Class QoS in UMTS Networks Conversational Streaming Interactive Background Maximum bit rate x x x x Delivery order x x x x Maximum SDU size SDU format information Delivery of erroneous SDUs Residual bit error rate x x x x x x x x x x x x x x SDU error ratio x x x x Transfer delay x x Guaranteed bit rate x x Traffic handling priority Allocation/retention priority x x x x x Fethi Filali 11

12 Agenda Heterogeneous wireless systems QoS in wireless networks QoS in UMTS Networks QoS in Networks Connecting UMTS and IPV6 Networks Radio Resource Management mechanism for UMTS networks QoS Management in Heterogeneous systems : Rhodos proposal Conclusion Fethi Filali 12

13 QoS in Networks The QoS support in EDCA is provided by the introduction of Access Categories (ACs) 4 different ACs within one station AC_VO: voice AC_VI: video AC_BE: best effort AC_BK: background Each AC has its own parameter set defined by the EDCA: Interframe spacing: Arbitration Inter-Frame Space (AIFS), etc. Contention windows: CWmin, CWmax Fethi Filali 13

14 QoS in Networks e introduces the Hybrid Coordination Function (HCF) for QoS Support HCF defines two medium access mechanisms: Contention-based channel access : Enhanced Distributed Channel Access (EDCA) Controlled channel access (including polling): HCF controlled channel access (HCCA) EDCA is used in the Contention Period phase HCCA is used in both phases: Contention Period (CP) and Contention Free Period (CFP) The HCF combines method of the PCF and DCF (the reason it is called hybrid) Fethi Filali 14

15 Legacy and e With Four ACs 4 Access Categories (ACs) within one station AIFS: Arbitration Inter-Frame Space Source: MANGOLD 2003 Fethi Filali 15

16 HCF Parameters AIFS[AC] = SIFS + AIFSN[AC] * aslottime aslottime: the duration of a slot AIFSN[AC] > 2 : AIFSN[AC] should be selected by the HC such as the earliest access time of EDCA stations is DIFS The smaller the AIFSN[AC], the higher the medium access priority CWmin[AC]: minimum contention window of AC CWmax[AC]: maximum contention window of AC: the smaller it is the higher the medium access priority e defines a maximum lifetime per MSDU: it can be useful since transmitting a frame too late is not meaningful to realtime applications Fethi Filali 16

17 An example of an e superframe The HC grants TXOPs in contention-free period and contention period Fethi Filali 17

18 Agenda Heterogeneous wireless systems QoS in wireless networks QoS in UMTS Networks QoS in Networks Connecting UMTS and IPV6 Networks Radio Resource Management mechanism for UMTS networks QoS Management in Heterogeneous systems : Rhodos proposal Conclusion Fethi Filali 18

19 Connecting UMTS and IPV6 Networks Eurecom UMTS Platform: The direct inter-connection between UMTS-TDD and IPv6 is performed using an adaptive protocol stack Fethi Filali 19

20 Connecting UMTS and IPV6 Networks Physical layer: made of the L1H and L1L sub-layers, follows also the UMTS-TDD standard. MAC, RLC and PDCP layers are compliant with the standard. Radio Resource Control (RRC): handles the control plane signalling of Layer 3 between the MTs and the AR. RRC messages carry all parameters to set up, modify and release layer 2 and layer 1 protocol entities and resources GRAAL (Generic Radio Access Adaptation Layer): provides the middleware for interfacing IPv6-based mechanisms for signalling and user traffic with 3GPP-specific mechanisms for the access network (e.g. for mobility, call admission, etc.) Fethi Filali 20

21 GRAAL External Interfaces Mobile Terminal Access Router GRAAL-MTC UA/QOS Application To network GRAAL- WLAN 1 2 IPV6 IPV6 6a 6b GMonitor 3 GRAAL- UMTS 5 GRAAL- UMTS 3 GMonitor 4a 4b ACCESS STRATUM ACCESS STRATUM Fethi Filali 21

22 GRAAL Functionalities User plane: Classifier for Radio Bearer Control plane Establishment/Release procedure of Mobile Station Establishment/Release procedure of Radio Bearer Mapping between UMTS and DiffServ QoS attributes Broadcasting (in Radio Gateway) of Neighbor Discovering messages (Router Advertisement, etc ) Neighboring cells list Neighboring cells quality list (in Mobile Station for IPv6 HandOvers) Computation of the IPv6 Link-local address Fethi Filali 22

23 DiffServ QoS DS field consists of a 6 bit codepoint a Per Hop Behavior (PHB) defines packet treatment; does not specify implementation, just service; not dependent on 5-tuple. Some PHB s standard, others experimental/proprietary Example PHBs and PHB Groups Best Effort: current best effort service Assured (AF): (RFC 2597) four classes, with three drop preferences per class Expedited (EF): (RFC 2598) priority, with rate limit, virtual leased line Issue: mapping between UMTS Traffic classes and DiffServ QoS classes Fethi Filali 23

24 Mapping of DiffServ and UMTS QoS Classes Name Service Class Relative Priority Service parameters Typical Usage Description Radio QoS Class SIG AF41 2a Unspecified Signalling (network usage) R1 S1 EF 1 Peak BW: 32 kbit/s Real time services R2 S2 AF21 2b CIR: 256 kbit/s Priority (urgent) data transfer R3 S3 AF1* 2c Three drop precedences (kbps): AF11 64 AF AF Olympic service (better then BE:streaming, ftp, etc) R4 R5 R6 S4 BE 3 Peak bit rate: 32 kbit/s Best Effort (BE) R7 S5 BE 3 Peak bit rate: 64 kbit/s Best effort R8 S6 BE 3 Peak bit rate: 256 kbit/s Best effort R9 S7 Special Service Requesting AAAC Contact for specific network characteristics (DSCP, bw, etc) N/A Fethi Filali 24

25 Agenda Heterogeneous wireless systems QoS in wireless networks QoS in UMTS Networks QoS in Networks Connecting UMTS and IPV6 Networks Radio Resource Management mechanism for UMTS networks QoS Management in Heterogeneous systems : Rhodos proposal Conclusion Fethi Filali 25

26 Rhodos RRM Architecture RRM TD-CDMA TD-CDMA QoS server JRRM RRM TD-CDMA Fethi Filali 26

27 Rhodos RRM architecture QoS server: manages CAC admission and QoS guaranties JRRM: manages resources allocation in UMTS/WLAN depending on QoS server request RRM entities: located at the RG (Radio Gateway) in UMTS and at the access router in WLAN support smart algorithms for resources allocation based minimum interferences, minimum node B transmitted power, channel state, etc. Fethi Filali 27

28 Rhodos Platform: location of RRM components RNC CAC RRM algo LC RM RNP Thresholds CAC: Call Admission Control for RT services LC: Load Control RG Node B UE PS: Packet scheduling for NRT services LC PS RM PC (outer loop) PC (inner loop) PS PC (outer loop) PC (inner loop) RM: Resource Manager PC: Power Control Fethi Filali 28

29 A Fair Opportunistic Scheduler for NRT Flows At step p+1, the scheduler selects the packet of user f p+1, so that packet size credit cost function of user i f p+ 1 = arg mini B( p) L i ( p) Ki ( p) φ i + U i ( p) flow weight U i ( p) = β log(1 E ( p)) i tuning parameter channel state of user i Fethi Filali 29

30 Packet scheduling for NRT services 25 Number of PDU selected, Beta = 0 channel state number of PDU served 20 Channel State Number of PDU selected TTI Fethi Filali 30

31 Packet scheduling for NRT services Fethi Filali 31

32 Packet scheduling for NRT services 25 Number of PDU selected by TTI, Beta = channel state Number of PDU selected 20 Channel State Number of PDU selected TTI Fethi Filali 32

33 Packet scheduling for NRT services beta = 0 beta = beta = Fairness of the scheduling 350 Number of PDU selected TTI Fethi Filali 33

34 Agenda Heterogeneous wireless systems QoS in wireless networks QoS in UMTS Networks QoS in Networks Connecting UMTS and IPV6 Networks Radio Resource Management mechanism for UMTS networks QoS Management in Heterogeneous systems : Rhodos proposal Conclusion Fethi Filali 34

35 QoS Support in Heterogeneous Networks Context: Rhodos project Problem: QoS management in heterogeneous wireless networks Solution: use of a modified version of SIP (Session Initiation Protocol): IETF RFC 3261 and 3GPP Rhodos-SIP is used for all user applications (not only for telephone calls and multimedia conferences) session establishment admission control resources reservation Fethi Filali 35

36 Rhodos Proposal Fethi Filali 36

37 Rhodos Transmission Services Non reliable: no guarantee from the network: UDP + IP best effort Reliable: no loss but no delay guarantee: TCP + IP best effort Elastic: user applications adapts to network conditions. The network guarantees minimal end-to-end delay and loss rate if the source rate does not exceed a given threshold Deterministic: The network always guarantees minimum endto-end delay and loss rate if the source rate does not exceed its requested rate Fethi Filali 37

38 Rhodos-SIP: without negotiation a UA a PS a JRM a JRM b PS b UA b b (0) INVITE (1) ADMISS. (2) Ok (3) INVITE (4) ADM ISS. (5) Ok (6) INVITE (7) (8) Ringing(9) Ringing (10) Ringing (11) (12) (13) Ok (14) RESERVE (15) Ok (16) Ok (17) RESERVE (18) Ok (19) Ok (20) (21) ACK (22) ACK (23) ACK (24) (25) Fethi Filali 38

39 Conclusion Issue: supporting QoS in heterogeneous wireless networks (UMTS, ) Eurecom research works: convergence between IPv6 and UMTS-TDD RRM scheme a SIP-based approach for QoS support in heterogeneous networks Future work: Mapping between UMTS QoS and e QoS classes Unified architecture between DiffServ and e Fethi Filali 39