Two-degree-of-freedom congestion control strategy against time delay and disturbance

Hao Wang, Wei Wei, Yanhua Li, Chenda Liao, Yan Qiao, Zuohua Tian

Research output: Chapter in Book/Report/Conference proceedingConference contribution

15 Scopus citations


Most of the existing congestion control schemes cannot guarantee the quality of service in wide-area networks with large round trip time (RTT). Aiming at the above problem, a two-degree-of-freedom congestion control strategy (named TCC) is proposed for improving the stability and robustness of the TCP/AQM system. TCC employs a modified Smith predictor with two additional controllers to compensate for the RTT delay. The feedback controller is designed by the internal model control theory for fast set-point tracking. The disturbance rejection controller is derived from frequency-domain analysis to reject external disturbance. Simulation results in NS2 demonstrate that TCC can effectively overcome the negative influence cased by time delay and disturbance. Compared with other congestion control schemes, our proposed method is superior in stabilizing the queue length with small jitters and rejecting disturbances.

Original languageEnglish (US)
Title of host publication2010 IEEE Global Telecommunications Conference, GLOBECOM 2010
PublisherInstitute of Electrical and Electronics Engineers Inc.
ISBN (Print)9781424456383
StatePublished - 2010
Externally publishedYes
Event53rd IEEE Global Communications Conference, GLOBECOM 2010 - Miami, FL, United States
Duration: Dec 6 2010Dec 10 2010

Publication series

NameGLOBECOM - IEEE Global Telecommunications Conference


Other53rd IEEE Global Communications Conference, GLOBECOM 2010
Country/TerritoryUnited States
CityMiami, FL


  • Active queue management
  • Congestion control
  • Internal mode control
  • Smith predictor
  • Time delay
  • Two-degree-of-freedom


Dive into the research topics of 'Two-degree-of-freedom congestion control strategy against time delay and disturbance'. Together they form a unique fingerprint.

Cite this