Document Type


Date of Award


Degree Name

Doctor of Philosophy in Electrical Engineering - (Ph.D.)


Electrical and Computer Engineering

First Advisor

Roberto Rojas-Cessa

Second Advisor

Nirwan Ansari

Third Advisor

Sotirios Ziavras

Fourth Advisor

Abdallah Khreishah

Fifth Advisor

Aleksandar Kolarov


A number of Internet applications require accurate characterization of different network parameters. There is, therefore, a need to determine whether the networks that carry packets for those applications comply with the requirements. Network measurement provides the means to perform this determination. This work focuses on schemes for measuring several parameters both in wired and wireless environments.

The need of measuring packet processing time (PPT) of the end hosts (i.e., workstations) in a wired network is unveiled. PPT is defined as the time elapsed between the arrival of a packet at the data-link layer and the time when the packet is time stamped at the application layer of the TCP/IP protocol stack of an end host, as defined by RFCs 2679 and 2681. The role of PPT becomes important to increase accuracy in the measurement of different network parameters (e.g., one way delay) as data rates increase.

Two schemes to measure the PPT of an end host have been proposed. The first scheme is designed to measure PPT of an end host using Internet Control Message Protocol (ICMP) packets and a specialized packet-capture card, given that the node is physically accessible. The second proposed scheme measures the PPT of a remote end host connected over a multiple-hop path based on the estimation of the capacity of the link connected to the end host using a packet-pair structure, called compound probe. Experimental evaluations in both testbed and Internet environments of the proposed schemes are presented.

A solution for measuring clock skew between two end hosts connected over a wired end-to-end path through the estimation of link capacity is proposed. Unlike existing schemes, the proposed solution is simple and does not require complex processing of the sampled data because the compound probe can also be used to detect data samples affected by noise (i.e., cross traffic) over the path. Simulation results of the proposed scheme are presented.

A scheme to measure the throughput of an IEEE 802.11 wireless access link in a hybrid wired-wireless path is introduced. Throughput estimation of a wireless access link is challenging and it can be affected by the cross traffic on the wired links and bottleneck- link location of the path. The proposed scheme measures the throughput of the download wireless link with high accuracy and without being affected by the cross traffic on the wired links and bottleneck-link location of a hybrid wired-wireless path. Experimental evaluations of the proposed scheme in a testbed environment are presented.



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