한국정보과학회논문지:정보통신 (Journal of KIISE:Information Networking)

한국정보과학회 (Korean Institute of Information Scientists and Engineers)
권호 표지

무선 ATM망에서 무선채널의 특성을 고려한 ABR 전송률 제어 방안

An ABR Rate Control Scheme Considering Wireless Channel Characteristics in the Wireless ATM Network

  • 이경주 ((주)삼성전자 통신연구소) ;
  • 민구 (한국통신 통신망연구소) ;
  • 최명환 (서강대학교 컴퓨터학과)
  • 발행 : 2000.06.30
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

에러율이 높은 무선채널 상에서 낮은 CLR(cell loss ratio)을 보장하는 ATM(asynchronous transfer mode) ABR(available bit rate) 서비스를 지원하기 위해서는 재전송이 요구된다. 무선 ATM에서는 ATM계층 하에 DLC(data link control)계층을 두어 DLC계층이 무선채널 상의 에러로 인해 요구되는 재전송과 재배열을 수행하도록 하여 높은 에러율을 갖는 무선채널의 특성이 낮은 에러율을 가정하여 설계된 ATM계층으로 전파되는 것을 막는다. 본 논문에서는 무선채널 상에서의 높은 에러율에 의한 전송률 감소를 반영하는 ABR 전송률 제어 방안을 제안함으로써 근원지의 전송률을 무선채널 상에서의 전송률에 보다 가깝게 맞추어 AP(access point)에서 발생할 수 있는 버퍼 오버플로우에 의한 셀손실을 줄였다. 채널의 상태를 ATM계층에 알리는 DLC계층을 가정한 모의실험을 통하여 제안하는 방안이 무선채널 상에서 기존의 방법보다 작은 크기의 ABR 큐를 사용하여 낮은 CLR을 보장함을 보였다. 또한 채널의 상태에 따라 전송률을 조정하는 DLC계층을 사용함으로써 무선 ATM에서 귀중한 자원인 무선링크를 보다 효율적으로 사용할 수 있음을 보였다.

Retransmissions on the DLC layer are essential to ABR service providing the low CLR (cell loss ratio) over the unreliable wireless channel with high bit error rate. In the wireless ATM, the DLC layer below ATM layer performs the retransmission and reordering of the cells to recover the cell loss over the wireless channel and by doing so, the effect of the wireless channel characteristics with high bit error rate can be minimized on the ATM layer which is designed under the assumption of the low bit error rate. We propose, in this paper, the schemes to reflect the changes of the transmission rate over the wireless channel on the ABR rate control. Proposed scheme can control the source rate to the changes of the transmission rate over the wireless channel and reduce the required buffer size in the AP (access point). In the simulation, we assume that the DLC layer can inform the ATM layer of the wireless channel quality as good or bad. Our simulation results show that the proposed schemes require the smaller buffer size compared with the existing scheme, enhanced dynamic max rate control algorithm (EDMRCA). It is also shown that the scheme with the intelligent DLC which adjusts the rate to the wireless channel quality not only provides the low CLR with smaller buffer requirement but also improves the throughput by utilizing the wireless bandwidth more efficiently.

키워드

참고문헌

  1. ATM Forum, ATM Traffic Management Specification Version 4.0, Apr. 1996. Available through http://ftp.atmforum.com/pub/approved-specs/af-tm-0056.000.ps
  2. P. Bhagwat, P. Bhattacharya, A. Krishna and S. Tripathi, 'Using Channel State Dependent Packet Scheduling to Improve TCP Throughput over Wireless LANs, Wireless Networks, Vol. 3, no. 1, 1997 https://doi.org/10.1023/A:1019132612232
  3. C. Fragouli, V. Sivaraman and M. Srivastava, 'Controlled Multimedia Wireless Link Sharing via Enhanced Class-Based Queueing with Channel-State-Dependent Packet Scheduling,' Proc. IEEE Infocom 98, Mar. 1998 https://doi.org/10.1109/INFCOM.1998.665077
  4. P. Agrawal, E. Hyden and P. Kryzanowski, 'An Experimental Indoor Wireless Network, SWAN: A Mobile Multimedia Wireless Network,' IEEE Personal Communications, Apr. 1996 https://doi.org/10.1109/98.490750
  5. D. Raychaudhuri, L. French and RSiracusa, 'WATMnet: A Prototype Wireless ATM System for Multimedia Personal Communication,' Proc. IEEE ICC 96, June 1996 https://doi.org/10.1109/ICC.1996.542242
  6. 'Magic WAND: Wireless ATM Network Demonstrator,' available at http://www. tik.ee.ethz.ch/~wand/
  7. J. Meierhofer, 'Data Link Control for Indoor Wireless ATM Networks,' Proc. Wireless 98, Jul. 1998
  8. R. Jain et al., 'ERICA Switch Algorithm: A Complete Description,' ATM Forum Contribution 96-1172
  9. F. Hartleb, 'A Simulation Study of ABR Protocols in ATM Networks,' Proc. IEEE ATM 97, May 1997 https://doi.org/10.1109/ATM.1997.624713
  10. F. Chiussi and Y. Wang, 'An ABR Rate-Based Congestion Control Algorithm for ATM Switches with Per-VC Queueing,' Proc. IEEE Globecom 97, Nov. 1997 https://doi.org/10.1109/GLOCOM.1997.638435
  11. F. Chiussi, Y. Xia and V. Kumar, 'Dynamic Max Rate Control Algorithm for Available Bit Rate Service in ATM Networks,' Proc. IEEE Globecom 96, Nov. 1996 https://doi.org/10.1109/GLOCOM.1996.592006
  12. M. Ritter, 'Network Buffer Requirements of the Rate-Based Control Mechanism for ABR Services,' Proc. IEEE Infocom 96, Apr. 1996 https://doi.org/10.1109/INFCOM.1996.493064
  13. J. Meierhofer, U. Bernhard and T. Hunziker, 'Finite State Radio Channel Model for Indoor Wireless ATM Networks,' Proc. ICT 98, Jun. 1998
  14. A. Arulambalam, X. Chen and N. Ansari, 'Allocating Fair Rates for Available Bit Rate Service in ATM Networks,' IEEE Communications Magazine, Nov. 1996 https://doi.org/10.1109/35.544198
  15. A. Romanow and S. Floyd, 'Dynamics of TCP Traffic over ATM Networks,' IEEE Journal on Selected Areas in Communications, Vol. 13, no.4, May 1995 https://doi.org/10.1109/49.382154