On the transmission opportunity and TCP throughput in cognitive radio networks

Abstract

SUMMARYThe characteristics of cognitive radio networks have huge impacts on the end‐to‐end performance of the transmission control protocol (TCP) for secondary users. Thus, the existing TCP throughput expression, widely used in wired and wireless networks, is no longer suitable for cognitive radio networks. In this paper, we derive the transmission opportunity of secondary users, taking into account the dynamics of spectrum availability, the overhead and errors of spectrum sensing, as well as the interaction between TCP and lower layers. The amount of transmission opportunity is expressed in terms of effective data transmission time. On the basis of the analysis of the transmission opportunity, an expression of an effective TCP throughput is then derived. To evaluate this effective TCP throughput expression, two cross‐layer optimization problems are formulated as application examples to maximize the transport layer effective throughput and energy utility, respectively. Simulation results show that our analysis on transmission opportunity is accurate, and the derived effective TCP throughput expression is more precise than existing ones. Copyright © 2012 John Wiley & Sons, Ltd.

Transport Protocols in Cognitive Radio Networks: A Survey

“…Protocols that change lower network layers to improve throughput at the transport layers were also investigated [22][23][24][25][26][27].…”

“…They mainly focused on the TCP throughput of SUs equipped with adaptive modulation and coding (AMC) at the physical layer and automatic repeat request (ARQ) as well as a finite size buffer at the link layer. For energy efficiency, Wang et al [27] provided a model to maximize the TCP throughput and energy utility by jointly optimizing spectrum sensing time, transmit power and forward error correction (FEC) redundancy, taking the sensing errors and the interaction between TCP and lower layers into account.…”

“…All of above mentioned transport protocols for CRNs have assumed that either all nodes are in CRNs [32][33][34][35][36][37][38][39][40][41][42] or the TCP sender side is in CR links [7,16,19,[21][22][23][24][25][26][27][28][29][30] or the TCP receiver side is in CR links [15,43]. In these proposals, lower layer information such as spectrum sensing status could be easily exploited to adjust the congestion window for maximizing the throughput.…”

“…Wang et al [27] Maximize the TCP throughput and energy utility by jointly optimizing spectrum sensing time, transmit power and FEC redundancy.…”

A version adaptive transcoding (VAT) mechanism for wireless mobile coverage networking

“…NetBlitz [10], TranSquid [11], and Chang [2] suggested transcoding models that use a caching platform; however, they focus on web objects instead of on wireless streaming media objects. Caching streaming media objects is more of a challenge than caching simple web objects, because the streaming media objects are larger in size.…”