1 / 24

UMTS simulator

UMTS simulator. Alberto Bona, Maurizio Conti. Politecnico di Torino. Scenario(1). General Assumption: Simulator time step is equal to 1 frame (10 ms) Advantages: Bit rate can be varied every TTI Transport channel accuracy Simpler and faster Limitations:

tawny
Download Presentation

UMTS simulator

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. UMTS simulator Alberto Bona, Maurizio Conti Politecnico di Torino

  2. Scenario(1) • General Assumption: • Simulator time step is equal to 1 frame (10 ms) • Advantages: • Bit rate can be varied every TTI • Transport channel accuracy • Simpler and faster • Limitations: • Power control is slot based  neglected • RACH and CPCH collisions are modelled on a frame basis 2 Alberto Bona, Maurizio Conti

  3. Scenario(2) • 1 RNC  SRNC  CRNC • Simulation of intra-RNC handover is possible • Simulation of inter-RNC handover is not precluded • Node-B number is an input parameter • Node-B inherits generic-BTS behaviour adding UMTS features • Structure is adherent to UMTS standards 3 Alberto Bona, Maurizio Conti

  4. Scenario(3) • RNC maintains (UTRAN-side) peer-UE protocol instantiation • RNC creates RRC layer which is responsible for channel allocation • RNC maintains UE schedulation references • Each Node-B has a MAC_CSH entity responsible for common transport channel transmission and reception 4 Alberto Bona, Maurizio Conti

  5. Protocol implementation(1): RACH • It’s an uplink transport channel • Slotted-aloha based, allows transmission of 1 frame • UE has to restart access procedure for each transmission • RACH will be used for low bit-rate data transmissions which don’t need high throughput 5 Alberto Bona, Maurizio Conti

  6. Protocol implementation(2): CPCH • It’s an uplink transport channel • Slotted-aloha based with fast acquisition indication and collision detection • UE, once access has been completed, is the owner of the code for NMAX consecutive frames • CPCH will be used for data transmissions which require higher throughput 6 Alberto Bona, Maurizio Conti

  7. Protocol implementation(3): DSCH • It’s a downlink transport channel • UE share the same code, multiplexed on a frame by frame basis • UE multiplexing is granted through polling on a signalling channel (at present Round Robin) • DSCH will be used for non real time traffic: WWW, FTP... 7 Alberto Bona, Maurizio Conti

  8. MAC-REQ. MAC-IND. MAC MS MAC MAC_D TX RX CSH RB_ mapping C/T INFO Switch MAC-REQ. TFCS C/T Demux DCH TF Flow -control buffer DCH buffer PHY-REQ PHY-IND. UE-structure (MAC_D) • RB_mapping_info: data (priority, log-CH_ID) for log-CH to tr-CH mapping • C/T switch: routes PDU towards TX buffers • TX buffers: on DCH or on common tr-CH • DCH TF: Transport Format for DCH; variable every TTI • C/T demux: allows demultiplexing of blocks from tr-CH to log-CH 8 Alberto Bona, Maurizio Conti

  9. CMAC REQ MAC MS MAC-c/sh MAC REQ TCTF - Insert TCTF -Read PHY IND RACH buffer CPCH buffer TF TF RACH CPCH MAC D PHY IND PHY IND PHY REQ PHY REQ DSCH (FACH) UE-structure (MAC_CSH) • TCTF-Insert: data and signalling multiplexing on transport channels • TX Buffers: on RACH and CPCH • RACH and CPCH TF: TF for transport channels • TCTF-Read: data (towards MAC_D) and signalling blocks demultiplexing 9 Alberto Bona, Maurizio Conti

  10. CMAC IND MAC UTRAN PHY IND TCTF - Read MAC D 1 MAC D 2 Scheduling Priority Handling TCTF - Insert MAC D n CPCH Controller RACH Controller MAC-c/sh RACH PHY CPCH PHY DSCH (FACH) TRANSFER TRANSFER PHY REQ PHY REQ UTRAN-structure (MAC_CSH) • Sheduling-Priority Handling: selects UE for TX on common transport CH. • Controllers: • RACH: manages collisions with a frame based model • CPCH: manages collisions (as RACH) and provides codes for UE transmissions • MAC_D list: maintains info about UE under Node B control 10 Alberto Bona, Maurizio Conti

  11. UMTS validation tests and simulations Alberto Bona, Maurizio Conti Politecnico di Torino

  12. Validation tests: RACH • Transfer delay has constant characteristics • Increasing UE number, arrived packets decrease because of collision • Mean transfer delay is independent by UE number 12 Alberto Bona, Maurizio Conti

  13. Validation tests: CPCH • 1 IP packet is transferred releasing signature  more than 1 max in picture • 1 IP packet needs 3 signature allocation to be transferred • time between max is due to signature contention or lack of codes 13 Alberto Bona, Maurizio Conti

  14. UMTS traffic sources • Based on UMTS 30.03 • 25 packet per ON session; OFF session: 3 s • 480 byte per packet • UDD64 • constant interarrival time between packets 62.5 ms • 2 blocks per frame • 320 bit per block • UDD144 • constant interarrival time between packets 27 ms • 4 blocks per frame • 360 bit per block 14 Alberto Bona, Maurizio Conti

  15. RACH Results: collision probability 15 Alberto Bona, Maurizio Conti

  16. RACH Results: throughput 16 Alberto Bona, Maurizio Conti

  17. CPCH Results: blocking probability 17 Alberto Bona, Maurizio Conti

  18. CPCH Results: throughput 18 Alberto Bona, Maurizio Conti

  19. CPCH Results: MAC transfer delay 19 Alberto Bona, Maurizio Conti

  20. DSCH Results: throughput-UDD144 20 Alberto Bona, Maurizio Conti

  21. DSCH Results: MAC transfer delay 21 Alberto Bona, Maurizio Conti

  22. GPRS-UMTS Comparison(1) • GPRS model: 1 PDCH signalling, 7 PDCH data, dynamic allocation, Round Robin scheduling • UMTS model: 3 codes per transport channel • Traffic source: UDD64 26 Alberto Bona, Maurizio Conti

  23. GPRS-UMTS Comparison(2) 27 Alberto Bona, Maurizio Conti

  24. GPRS-UMTS Comparison(3) 28 Alberto Bona, Maurizio Conti

More Related