TY - GEN
T1 - Enhanced bandwidth allocation for TCP flows in WiMAX networks
AU - Park, Eun Chan
AU - Hu, Chunyu
AU - Kim, Hwangnam
PY - 2009
Y1 - 2009
N2 - In this paper,we propose a bidirectional bandwidth-allocation mechanism to improve TCP performance in the IEEE 802.16 WiMAX networks. 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 mechanism that couples the bandwidth allocation for uplink and downlink connections by using either proactive bandwidth allocation or 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.
AB - In this paper,we propose a bidirectional bandwidth-allocation mechanism to improve TCP performance in the IEEE 802.16 WiMAX networks. 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 mechanism that couples the bandwidth allocation for uplink and downlink connections by using either proactive bandwidth allocation or 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.
KW - Bandwidth request & allocation
KW - IEEE 802.16e MAC
KW - TCP performance
UR - http://www.scopus.com/inward/record.url?scp=84885889746&partnerID=8YFLogxK
U2 - 10.1007/978-3-642-10625-5_23
DO - 10.1007/978-3-642-10625-5_23
M3 - Conference contribution
AN - SCOPUS:84885889746
SN - 3642106242
SN - 9783642106248
T3 - Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering
SP - 363
EP - 379
BT - Quality of Service in Heterogeneous Networks - 6th Int. ICST Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2009 and AAA-IDEA 2009, Proceedings
T2 - 6th International ICST Conference on Heterogeneous Networking for Quality, Reliability, Security and Robustness, QShine 2009 and 3rd International Workshop on Advanced Architectures and Algorithms for Internet Delivery and Applications, AAA-IDEA 2009
Y2 - 23 November 2009 through 25 November 2009
ER -