On the Effect of Feedback Errors in Markov Models for SR ARQ Packet Delays

Abstract

Modern communication systems require effective error control techniques for wireless links. This problem is still relevant in many applications involving recently developed IEEE standards such as 802.16, or sensors for environmental monitoring in extreme conditions. A notable example is also underwater communication with acoustic transmission, where long delays may be present. Usually, such studies assume the availability of an error-free feedback channels which is used to perform retransmission requests in an ARQ fashion. This paper discusses the performance of the Selective Repeat ARQ scheme in terms of packet delay when the feedback that is sent back at the transmitter's side can be erroneous. A non instantaneous noisy feedback and a Bernoulli arrival process, for different traffic intensities, are considered. The system is modeled through Discrete Time Markov Chains, including the channel and the ARQ state. The system equations are derived and solved, and the impact of erroneous feedback is quantified. With respect to other similar contributions, the proposed approach presents the advantage of being directly implementable in any analysis using Markov chains to evaluate the system properties, instead of dedicated models. It can therefore be extended to a plethora of different scenarios, including different channel models and also including FEC features so as to obtain a Hybrid ARQ scheme.Index Terms-Queueing analysis, automatic repeat request, Markov processes, error analysis.

Analysis of SR ARQ delays using data-bundling over Markov channels

“…These are very common assumptions for the sake of clarity and they do not change the analysis substantially [10]. Further, we assume that the link layer is fully reliable, that is, every packet is transmitted (and retransmitted if needed) until it is received correctly.…”

“…Another related contribution is presented in [2], where the accurate approximation of packet delay statistics is discussed. In [10], SR ARQ was investigated in the presence of feedback errors, and it was discussed how this affects the packet delays.…”

Adaptive Generative Models for Digital Wireless Channels

“…Generative models are very efficient as they decrease the computation burden of real or simulation systems and subsequently they significantly reduce the simulation time. The main application of error models is to assess the performance and assist in the design of error control schemes and also the design of high layer wireless communication protocols [5]- [9]. Error models can characterize erroneous bit or packet sequences [10], [11].…”

Adaptive HEC-VPS: The Real-time Reliable Wireless Multimedia Multicast Scheme

“…We thus adopt SR, NACK-only based retransmission scheme in this general architecture of EEC for real-time multicast services. Additionally, many recent studies have shown that the Gilbert-Elliott (GE) model is a very good approximation for the packet loss model in a wireless channel [9]. Therefore, we will evaluate the throughput performance of the architecture using GE channel model in this paper.…”

“…In this paper, for those parameterizations that include retransmissions, rather than focusing on a particular transport protocol, we consider a generic retransmission based scheme with the following feature: A Selective Repetition (SR), Negative-Acknowledgment (NACK)-only retransmission scheme is used. Actually, most real-time multicast transport protocols suggested to use a SR scheme rather than Go-Back-N due to its efficiency [9][10] [11]. We thus adopt SR, NACK-only based retransmission scheme in this general architecture of EEC for real-time multicast services.…”