Christina Parsa and J. J. Garcia-Luna-Aceves. Improving TCP performance over wireless networks at the link layer. ACM Mobile Networks and Applications, 5(1):57-- 71, March 2000.  Home/Search   Document Details and Download   Summary   Related Articles   Check

....is used to provide communication routes among the devices. Several problems were experienced by using TCP (Transmission Control Protocol) over wireless networks as mentioned in other studies [18] 19] 20] Even though some studies have tried to improve TCP performance over wireless networks [21], 22] no standard has been established. A simple reliable transport protocol based on a stop and wait mechanism was therefore developed in order to provide communication among the wireless devices. Error margins were calculated for 95 confidence intervals relative to the measures mean value. ....

C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP performance over wireless networks at the link layer," ACM Mobile Networks and Applications, vol. 5, no. 1, pp. 57--71, Mar. 2000.

....congestion related losses from wireless losses. These solutions have been proposed at various layers of the protocol stack and can be mainly classified as link layer mechanisms, transport layer mechanisms, and also newer versions of TCP. Snoop [3] Delayed Duplicate Acknowledgments [23] and TULIP [19] are examples of link layer mechanisms. I TCP [9] and M TCP [4] Explicit Loss Notification [6] Explicit Bad State Notification [5] and Explicit Congestion Notification [22] are examples of transport layer mechanisms. Although newer TCP versions have been proposed to address specific issues ....

.... layer retransmission mechanisms can sometimes adversely affect the operation of other layers leading to excessive retransmissions, as suggested in [10] The most important link layer solutions include Snoop [3] the TCP Unaware Approach [23] and TULIP (Transport Unaware Link Improvement Protocol) [19]. TULIP is a link layer solution 0 0.5 1 1.5 2 2.5 Tahoe with Snoop Reno with Snoop Newreno with Snoop SACK with Snoop Vegas with Snoop Sequence Number Fig. 2. TCP Performance over Wireless Networks with Snoop for half duplex links. This protocol is still in its ....

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C. Parsa and J. J. Garcia-Luna-Aceves. Improving TCP Performance over Wireless Networks at the Link Layer. Mobile Networks and Applications, 5(1):57--71, 2000.

....or at the MH inform the TCP sender at the FH about the state of the wireless link (loss packets, handovers, etc. e.g. in [8] the TCP sender gets information about the handovers. Link layer proposals: With these types of proposals the Base Station makes retransmissions at the radio link layer [9]. They depend on the type of radio link protocols used for each wireless network. III. SIMULATOR STRUCTURE The GPRS simulation model has been created with the event driven simulator Cadence Bones Designer. We simulate the FTP transmission of a 512 Kbytes data file from a FTP server attached to ....

C. Parsa and J.J. Garcia-Luna-Aceves, "Improving TCP performance over wireless networks at the link layer", Mobile Networks and Applications 5 (2000), P. 57-71, Baltzer Science Publishers.

....network. I. INTRODUCTION The performance of TCP over heterogeneous connections such as those including satellite and wireless links has been extensively studied for the past few years. Proposed performance enhancing techniques can roughly be categorized into link layer solutions (see for example [1], 2] end to end solutions where the end to end semantic of TCP is maintained (see for example [3] 4] 5] 6] 7] 8] 9] 10] and non end to end solutions where the end to end semantic is violated (see for example [11] 12] 13] Various link layer and end to end approaches can be ....

C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP Performance Over Wireless Network at The Link Layer," ACM Mobile Networks & Applications Journal, 1999.

....take only few exchanges before the new BS updates its state. The duration of the handoff is really short since no state change occurs in between. Most of the schemes proposed for the performance improvement do not make any assumptions about the MAC layer issues. Only certain schemes like TULIP [13] address these issues. TULIP The protocol TULIP, transport unaware link layer improvement protocol [13] is service aware but not protocol aware. TULIP provides reliability only to the packets that require such service (serviceaware) and the details of the protocol is not needed to be known for ....

....since no state change occurs in between. Most of the schemes proposed for the performance improvement do not make any assumptions about the MAC layer issues. Only certain schemes like TULIP [13] address these issues. TULIP The protocol TULIP, transport unaware link layer improvement protocol [13], is service aware but not protocol aware. TULIP provides reliability only to the packets that require such service (serviceaware) and the details of the protocol is not needed to be known for which this service is being provided (not protocol aware) In specific, it can be said that TULIP ....

C. Parsa and J.J. Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at the Link Layer", in Mobile Networks and Applications, 1999. 22

....a system. I. INTRODUCTION The performance of TCP over heterogeneous connections such as those including satellite and wireless links has been extensively studied for the past few years. Proposed performance enhancing techniques can roughly be categorized into link layer solutions (see for example [1], 2] end to end solutions where the end to end semantic of TCP is maintained (see for example [3] 4] 5] 6] 7] 8] 9] 10] and non end to end solutions where the end to end semantic is violated (see for example [11] 12] 13] Various link layer and end to end approaches can be ....

C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP Performance Over Wireless Network at The Link Layer," ACM Mobile Networks & Applications Journal, 1999.

....by random loss. Some of them try to hide all non congestion related losses from the TCP sender. The idea behind these approaches is that since the problem is local for the wireless part of the link, it must be solved locally (e.g. splitting [BB94] snoop [Bal97] or different link layer solutions [PA98, CZT99]) Others attempt to make the TCP sender aware of existing wireless hops and that some packet losses are not due to congestion. The sender can then avoid invoking the congestion control algorithm when non congestion related losses occur (e.g. ELN [Bal97] ECN [Flo94] EBSN [BKVP96] Freeze TCP ....

....of the loss is random loss rather than congestion loss. The end result when random losses are considerable is a small average window size, with only a small number of outstanding segments. As compared to the above solutions implemented at the TCP level, link level solutions to lossy networks [PA98, CZT99] are also proposed. Forward error correction (FEC) codes and automatic retransmission systems (ARQ) can be used on the wireless link. FEC introduces a relatively constant coding delay and a bandwidth overhead into the path, but cannot correct all forms of bit corruptions. ARQ uses a stop and ....

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C. Parsa and JJ Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at The Link Layer," http://www.cse.ucsc.edu/research/ccrg/CMPE252/readings.html "

....is the case for many categories of wireless. FEC can detect and reverse a limited number of bits, but the penalty in bandwidth can be considerable. For example, the raw bit rate for CDPD, which uses FEC, is 19.2 kb s, while the actual user bit rate is 9 13 kb s [16] In addition, the authors in [51] argue that the use of FEC means more power consumption and computation delays per packet. Tabbane [16] also notes that FEC requires fast digital signal processing chips, which do indeed consume additional power. A question that still remains unresolved is whether the LL protocol should be aware ....

....disconnections are common [53] TCP Unaware LL Protocols TCP unaware LL protocols, in principle, help to preserve protocol layer modularity, and as such can be extended to accommodate transport protocols other than TCP. TULIP The Transport Unaware Link Improvement Protocol (TULIP) [51] was designed for half duplex wireless channels with limited bandwidth. TULIP is not aware of the transport protocol per se, but it is aware of the type of service requested (e.g. reliable service for TCP vs. unreliable for UDP) In other words, TULIP requires the network protocol (in this case ....

C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at the Link Layer," Mobile Networks and Applications, 1999.

....as is the case for many categories of wireless. FEC can detect and reverse a limited number of bits, but the penalty in bandwidth can be considerable. For example, the raw bit rate for CDPD, which uses FEC, is 19.2 Kbps, while the actual user bit rate is 9 13Kbps [73] In addition, the authors in [52] argue that the use of FEC means more power consumption and computation delays per packet. Tabbane [73] also notes that FEC requires fast digital signal processing chips, which do indeed consume additional power. A question that still remains unresolved is whether the LL protocol should be aware ....

....to prevent TCP retransmissions: LL and TCP retransmissions interfere, leading to worse performance. Finally snoop does not perform well when long or frequent disconnections are common [15] 2.1.2 TCP unaware LL protocols 2.1.2. 1 TULIP The Transport Unaware Link Improvement Protocol (TULIP) [52] was designed for halfduplex wireless channels with limited bandwidth. TULIP is not aware of the transport protocol per se, but it is aware of the type of service requested (e.g. reliable service for TCP vs. unreliable for UDP) In other words, TULIP requires the network protocol (in this case IP) ....

C. Parsa and J.J. Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at the Link Layer", in Mobile Networks and Applications, 1999.

....in [6] suggest that if such a solution were accepted, it has to be tightly coupled with TCP. Nevertheless, the developers of TULIP (Transport Unaware Link Improvement Protocol) show that over half duplex radio channels an uncoupled solution is indeed possible, and can yield better performance [22]. 1.3.2 TCP aware LL proposals The most prominent proposal in this category is the SNOOP protocol [6] SNOOP lies in an intermediate position between the previous and the next category of proposals, trying to utilize the ability of a LL protocol to respond fast, and at the same time using 4 the ....

C. Parsa and J.J. Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at the Link Layer", Mobile Networks and Applications, 1999

....in particular, is an ever increasing practice of mobile users world wide, resulting in the need for reliable client server communication over wireless links. Unfortunately, the de facto Internet protocol for reliability, TCP, has severe performance problems when operated over wireless links [12] 2][11]. Recent research has focussed on the problems associated with TCP performance in the presence of wireless links and ways to improve its performance. The key issue lies at the very heart of TCP s congestion control algorithms: namely, packet loss is the only detection mechanism for congestion in ....

.... losses as congestive by reducing its transmission window (and in effect halving the throughput of the connection) Many proposals to improve TCP performance have focussed on hiding wireless losses from TCP by performing retransmissions of any lost data before TCP notices the loss [1] 3] 6] 4] 5][11]. There is far less research on methods for TCP to differentiate between losses due to congestion and those due to noise on a wireless channel This work was supported in part at UCSC by the Office of Naval Research (ONR) under Grant N00014 99 1 0167. 7] 9] In this paper we extend our protocol ....

C. Parsa and J.J. Garcia-Luna-Aceves. Improving TCP performance over wireless networks at the link layer. ACM Mobile Networks and Applications Journal, 5(1):57--71, 2000.

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Christina Parsa and J. J. Garcia-Luna-Aceves. Improving TCP performance over wireless networks at the link layer. ACM Mobile Networks and Applications, 5(1):57-- 71, March 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP performance over wireless networks at the link layer," ACM Mobile Networks and Applications, vol. 5, 2000.

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C. Parsa and J.J. Garcia-Luna-Aceves, "Improving TCP performance over wireless networks at the link layer," Mobile Networks and Applications, vol. 5, no. 1, pp. 57--71, 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP performance over wireless network at the link layer," Mobile Networks & Applications, vol. 5, no. 1, pp. 57--71, 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP performance over wireless network at the link layer," Mobile Networks & Applications, 5(1):57--71, 2000.

No context found.

C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP performance over wireless networks at the link layer," ACM Mobile Networks and Applications J., vol. 5, no. 1, pp. 57--71, 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves. Improving TCP Performance over Wireless Networks at the Link Layer. ACM Mobile Networks and Applications Journal, 5(1):57--71, 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves. Improving TCP Performance over Wireless Networks at the Link Layer. ACM Mobile Networks and Applications Journal, 5(1):57--71, 2000.

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Parsa, C. and J. J. Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at the Link Layer", ACM Mobile Networks and Applications Journal, (5)1, pp. 57-71, 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP Performance over Wireless Networks at the Link Layer", Mobile Networks and Applications, vol. 5, no. 1, 2000.

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C. Parsa and J. J. Garcia-Luna-Aceves, "Improving TCP Performance Over Wireless Network at The Link Layer," ACM Mobile Networks & Applications Journal, 1999.

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C. Parsa and J.J. Garcia-Luna-Aceves, "Improving TCP performance over wireless networks at the link layer," Mobile Networks and Applications, vol. 5, no. 1, pp. 57--71, 2000.

No context found.

Christina Parsa and J. J. Garcia-Luna-Aceves. Improving TCP performance over wireless networks at the link layer. ACM Mobile Networks and Applications, 5(1):57--71, March 2000.

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C. Parsa, J.J. Garcia-Luna-Aceves, Improving TCP performance over wireless network at the link layer, ACM Mobile Netw. Appl. J. (1999).

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