Basics of qualitative research: Grounded theory procedures and techniques

This ebook is the first authorized digital version of Kernighan and Ritchie's 1988 classic, The C Programming Language (2nd Ed.). One of the best-selling programming books published in the last fifty years, "K&R" has been called everything from the "bible" to "a landmark in computer science" and it has influenced generations of programmers. Available now for all leading ebook platforms, this concise and beautifully written text is a "must-have" reference for every serious programmers digital library.

As modestly described by the authors in the Preface to the First Edition, this "is not an introductory programming manual; it assumes some familiarity with basic programming concepts like variables, assignment statements, loops, and functions. Nonetheless, a novice programmer should be able to read along and pick up the language, although access to a more knowledgeable colleague will help."

The C programming language

This document provides updates to IEEE Std 802.16's MIB for the MAC, PHY and asso- ciated management procedures in order to accommodate recent extensions to the standard.

IEEE Standard for Local and Metropolitan Area Networks Part 16: Air Interface for Fixed Broadband Wireless Access Systems Draft Amendment: Management Information Base Extensions

Computational geometry

The Transmission Control Protocol.

Cross-layer design optimizations in wireless protocol stacks

Radio frequency identification (RFID) is a means to identify and track objects using radio frequency transmission An RFID system consists of readers and tags Readers use radio signals to communicate with the tags The tags may be active (battery powered) or passive (powered by the reader's signals) RFID is increasingly being used in many applications such as inventory management, object tracking, retail checkout etc The reader collision problem occurs when the signal from one reader interferes with the signal from other readers Such interference can result in lack of communication between the readers and some of the tags in the vicinity leading to incorrect and inefficient operation of an RFID system This problem is further aggravated when mobile/hand-held readers are used in the system The evolving standards like ETSI EN 302 208 for RFID readers use a CSMA based protocol called "listen before talk" to reduce the reader collision problem However, carrier sensing alone cannot solve the reader collision problem in RFID networks For example, the signals from two readers that are out of range from each other, may still collide at the tags in the region between them Although this aspect of the reader collision problem seems similar to the hidden terminal problem encountered in traditional wireless systems, existing solutions such as RTS-CTS mechanisms are not applicable One of the reasons being: a reader may communicate with multiple tags simultaneously Hence a separate collision avoidance is required between CTS sent by these multiple tags, making the protocol more complicated In this paper, we describe Pulse, a distributed protocol to reduce reader collisions The operation of the Pulse protocol is based on periodic beaconing on a separate control channel by the reader, while it is reading the tags The protocol functions effectively not only with fixed RFID readers but also with mobile RFID readers We show, using simulation in QualNet, that using Pulse protocol, the throughput (overall read rate) is increased by as high as 60% as compared to "listen before talk" (CSMA) and by 232% as compared to Colorwave We also present an analytical model for our protocol in a single hop scenario

/pdf/mitigating-the-reader-collision-problem-in-rfid-networks-18whr1mfcv.pdf

Mitigating the reader collision problem in RFID networks with mobile readers

The enhancements to the IEEE 802.11 DCF MAC protocol which enable nodes to identify themselves as exposed nodes and to opportunistically schedule concurrent transmissions whenever possible, thereby improving utilization and mitigating the exposed node problem are described. The algorithm makes minimal changes to the IEEE 802.11 MAC protocol. It does not require the introduction of new frame types or changes to existing frame formats. We show, using simulations in GloMoSim, that it provides significant improvement in throughput.

/pdf/mitigating-the-exposed-node-problem-in-ieee-802-11-ad-hoc-2ywk5kipgp.pdf

Mitigating the exposed node problem in IEEE 802.11 ad hoc networks

Applications using traditional protocol stacks (e.g., TCP/IP) from wired networks do not function efficiently in mobile wireless environments. This is primarily due to the layered architecture and implementation of protocol stacks. One mechanism to improve the efficiency of the stack is cross-layer feedback, that is, making information from within one layer available to another layer of the stack. For example, TCP retransmissions can be reduced by making it aware of network disconnections or handoff events. We highlight the need for a cross-layer feedback architecture and identify key design goals for an architecture. We present our ECLAIR architecture, which satisfies these design goals. We describe a prototype implementation that validates ECLAIR. We also discuss other cross-layer architectures and provide a cross-layer design guide.

/pdf/cross-layer-feedback-architecture-for-mobile-device-protocol-2n2tgyomh2.pdf

Cross-layer feedback architecture for mobile device protocol stacks

The reader collision problem occurs when the signal from one reader interferes with the signal from other readers. Solutions like RTS-CTS are not applicable because a reader may communicate with multiple tags simultaneously. In this paper, we describe Pulse, a distributed protocol to reduce reader collisions. The operation of the Pulse protocol is based on periodic beaconing on a separate control channel by the reader, while it is reading the tags. The protocol functions effectively with fixed as well as mobile RFID readers. We show, using simulation in QualNet, that using Pulse protocol, the throughput (overall read rate) is increased by as high as 98%(with 49 readers) as compared to “Listen Before Talk” (CSMA) and by 337%(with 9 readers) as compared to Colorwave. We also present an analytical model for our protocol in a single hop scenario.

https://www.it.iitb.ac.in/~sri/papers/pulse-usn05.pdf

Sridhar Iyer

Papers

Cross-layer design optimizations in wireless protocol stacks

Mitigating the reader collision problem in RFID networks with mobile readers

Mitigating the exposed node problem in IEEE 802.11 ad hoc networks

Cross-layer feedback architecture for mobile device protocol stacks

PULSE: a MAC protocol for RFID networks