TCP-aware bidirectional bandwidth allocation in IEEE 802.16 networks

Eun Chan Park, Hwangnam Kim

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


In this paper, we propose a bidirectional bandwidth-allocation mechanism to improve TCP performance in the IEEE 802.16 broadband wireless access networks. By coupling the bandwidth allocation for uplink and downlink connections, the proposed mechanism increases the throughput of the downlink TCP flow and it enhances the efficiency of uplink bandwidth allocation for the TCP acknowledgment (ACK). According to the IEEE 802.16 standard, when serving a downlink TCP flow, the transmission of the uplink ACK, which is performed over a separate unidirectional connection, incurs additional bandwidth-request/ allocation delay. Thus, it increases the round trip time of the downlink TCP flow and results in the decrease of throughput accordingly. First, we derive an analytical model to investigate the effect of the uplink bandwidth-request/ allocation delay on the downlink TCP throughput. Second, we propose a simple, yet effective, bidirectional bandwidth-allocation scheme that combines proactive bandwidth allocation with piggyback bandwidth request. The proposed scheme reduces unnecessary bandwidth-request delay and the relevant signaling overhead due to proactive allocation; meanwhile, it maintains high efficiency of uplink bandwidth usage by using piggyback request. Moreover, our proposed scheme is quite simple and practical; it can be simply implemented in the base station without requiring any modification in the subscriber stations or resorting to any cross-layer signaling mechanisms. The simulation results ascertain that the proposed approach significantly increases the downlink TCP throughput and the uplink bandwidth efficiency.

Original languageEnglish
Pages (from-to)2123-2138
Number of pages16
JournalWireless Networks
Issue number8
Publication statusPublished - 2010 Nov

Bibliographical note

Funding Information:
Acknowledgments This work was supported in part by the Don-gguk University Research Fund of 2009, in part by R&D program of MKE/IITA [2008-F-015-02, Research on Ubiquitous Mobility Management Methods for Higher Service Availability], and in part by Industrial Source Technology Development Programs (Project No. 10033347) funded by the Ministry of Knowledge Economy (MKE, Korea).


  • Bandwidth request & allocation
  • Broadband wireless access networks
  • IEEE 802.16e MAC
  • TCP performance

ASJC Scopus subject areas

  • Information Systems
  • Computer Networks and Communications
  • Electrical and Electronic Engineering


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