Sumantra R. Kundu

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This paper evaluates the performance of practical Rate Control Algorithms (RCAs) operating at the Media Access Control (MAC) layer in IEEE 802.11 networks built on Atheros chipsets. Using a dual band 32bit cardbus based wireless network interface card (WNIC) on a laptop running vanilla Linux 2.6.13.3 kernel, we explore the capabilities of each of the three(More)
—Opportunistic scheduling algorithms are effective in exploiting channel variations and maximizing system throughput in multirate wireless networks. However, most scheduling algorithms ignore the per-user quality-of-service (QoS) requirements and try to allocate resources (for example, the time slots) among multiple users. This leads to a phenomenon(More)
In this paper we study the causal behavior of Rayleigh fading wireless channel and a single queue system buffer using the finite state Markov chain (FSMC) and the finite buffer fluid flow model. In the process, we propose a state partitioning scheme for capturing the wireless channel realities based on the combined effect of level crossing rate (LCR),(More)
In networks carrying large volume of traffic, accurate traffic characterization is necessary for understanding the dynamics and patterns of network resource usage. Previous approaches to flow characterization are based on random sampling of the packets (e.g., Cisco's NetFlow) or inferring characteristics solely based on long lived flows (LLFs) or on lossy(More)
Current scheduling techniques used for cellular networks do not suffice for the emerging multi-rate systems like cdma2000 and High Data Rate (HDR). Real-time applications like video streaming must comprehend the channel conditions and consequently the data rates that are currently being supported; accordingly the content and the amount of data to be(More)
Emerging multi-rate wireless systems both cellular (cdma2000, high data rate (HDR)) and Wi-Fi like systems demand that the currently used channel estimation and scheduling techniques be revisited. Not only the channel estimation, prediction algorithms, and protocols need to be modified, the premise for evaluating their performance needs to be changed.(More)
This paper proposes a new measurement architecture and associated traffic estimation algorithm called FastFlow that uses the heavy-tailed nature of Internet traffic in order to distinguish packets belonging to short lived flows (SLFs) and long lived flows (LLFs). While complete information is stored for SLFs, only partial information related to LLFs is(More)