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Wireless communication iscurrently in a state of rapid evolution. This evolution is driven by the numerous advantages of the wireless networks. One major constraint to this evolution is the lack of standardization. Also a major concern are the interference problems of the signal at thereception point caused by themultiple paths that the electromagnetic waves travel (multi-path interference). This thesispresents two separate simulations. In the first, a realistic physical model of a wireless local area network is developed. In this simulation, the multi-path interference at the reception point is investigated. The results of this physics- based simulation are used to assess an important assumption in the second simulation. In the second simulation, we examine the reliability of the wireless standard for the medium access control (MAC) layer, using CACI COMNET ffi network simulation software. This standard was published in 1997, by the IEEE's working group 802.11 and in this thesis is tested and analyzed under different network loads. One major result is that the optimum load for a five working stations wireless LAN, is from 80 to 200 packets per second. Below that load range the channel utilization is small and above that the network is overloaded.

Wireless communication iscurrently in a state of rapid evolution. This evolution is driven by the numerous advantages of the wireless networks. One major constraint to this evolution is the lack of standardization. Also a major concern are the interference problems of the signal at thereception point caused by themultiple paths that the electromagnetic waves travel (multi-path interference). This thesispresents two separate simulations. In the first, a realistic physical model of a wireless local area network is developed. In this simulation, the multi-path interference at the reception point is investigated. The results of this physics- based simulation are used to assess an important assumption in the second simulation. In the second simulation, we examine the reliability of the wireless standard for the medium access control (MAC) layer, using CACI COMNET ffi network simulation software. This standard was published in 1997, by the IEEE's working group 802.11 and in this thesis is tested and analyzed under different network loads. One major result is that the optimum load for a five working stations wireless LAN, is from 80 to 200 packets per second. Below that load range the channel utilization is small and above that the network is overloaded.

Wireless communication iscurrently in a state of rapid evolution. This evolution is driven by the numerous advantages of the wireless networks. One major constraint to this evolution is the lack of standardization. Also a major concern are the interference problems of the signal at thereception point caused by themultiple paths that the electromagnetic waves travel (multi-path interference). This thesispresents two separate simulations. In the first, a realistic physical model of a wireless local area network is developed. In this simulation, the multi-path interference at the reception point is investigated. The results of this physics- based simulation are used to assess an important assumption in the second simulation. In the second simulation, we examine the reliability of the wireless standard for the medium access control (MAC) layer, using CACI COMNET ffi network simulation software. This standard was published in 1997, by the IEEE's working group 802.11 and in this thesis is tested and analyzed under different network loads. One major result is that the optimum load for a five working stations wireless LAN, is from 80 to 200 packets per second. Below that load range the channel utilization is small and above that the network is overloaded.

Wireless communication iscurrently in a state of rapid evolution. This evolution is driven by the numerous advantages of the wireless networks. One major constraint to this evolution is the lack of standardization. Also a major concern are the interference problems of the signal at thereception point caused by themultiple paths that the electromagnetic waves travel (multi-path interference). This thesispresents two separate simulations. In the first, a realistic physical model of a wireless local area network is developed. In this simulation, the multi-path interference at the reception point is investigated. The results of this physics- based simulation are used to assess an important assumption in the second simulation. In the second simulation, we examine the reliability of the wireless standard for the medium access control (MAC) layer, using CACI COMNET ffi network simulation software. This standard was published in 1997, by the IEEE's working group 802.11 and in this thesis is tested and analyzed under different network loads. One major result is that the optimum load for a five working stations wireless LAN, is from 80 to 200 packets per second. Below that load range the channel utilization is small and above that the network is overloaded.

The Data Management System network is a complex and important part of manned space platforms. Its efficient operation is vital to crew, subsystems and experiments. AI is being considered to aid in the initial design of the network and to augment the management of its operation. The Intelligent Resource Management for Local Area Networks (IRMA-LAN) project is concerned with the application of AI techniques to network configuration and management. A network simulation was constructed employing real time process scheduling for realistic loads, and utilizing the IEEE 802.4 token passing scheme. This simulation is an integral part of the construction of the IRMA-LAN system. From it, a causal model is being constructed for use in prediction and deep reasoning about the system configuration. An AI network design advisor is being added to help in the design of an efficient network. The AI portion of the system is planned to evolve into a dynamic network management aid. The approach, the integrated simulation, project evolution, and some initial results are described.

The IEEE 802.11b wireless local area networking (WLAN) protocol does not specify a maximum permissible range limitation. Rather, the protocol permits network data rates to vary based on the instantaneous link conditions present. This thesis analyzes the impact of distance on perceived network link quality for IEEE 802.11b WLAN systems. An experimental IEEE 802.11b wireless network testbed is developed and deployed within a metropolitan area (1-40 kilometers) for the quantitative analysis of link quality for various realistic types of network traffic. Additionally, the functional limitations of individual system components are identified for consideration in the planning of future experiments.

The IEEE 802.11b wireless local area networking (WLAN) protocol does not specify a maximum permissible range limitation. Rather, the protocol permits network data rates to vary based on the instantaneous link conditions present. This thesis analyzes the impact of distance on perceived network link quality for IEEE 802.11b WLAN systems. An experimental IEEE 802.11b wireless network testbed is developed and deployed within a metropolitan area (1-40 kilometers) for the quantitative analysis of link quality for various realistic types of network traffic. Additionally, the functional limitations of individual system components are identified for consideration in the planning of future experiments.

This thesis extends the multi-computer real-time executive, MCORTEX. The multiple cluster system RTC* (Real Time Cluster Star), consisting of clusters of single board computers (INTEL iSBC 86/12A), which are connected via an Ethernet Local Area Network, serves as a hardware basis for the implementation of extended MCORTEX. The extension upgrades MCORTEX to system-wide synchronization and general data communication between any processes in the system. An intercluster shared memory model is developed, that partially replicates intracluster shared memory, such that shared data replication is minimized and the system's processing speed is maximized. This implementation, by transmitting produced shared data to all consuming clusters as soon as possible after production, guarantees that only cluster local hits occur in the system. Shared memory space is used efficiently by transmitting shared data to consuming clusters only, and by the ability to store shared data contiguously in intracluster shared memory.

Title from cover

Title from cover

This thesis deals with the features and performance of a network interface device to interconnect two remote Fiber Distributed Data Interface (FDDI) Local Area Networks (LANs) through the Critical Data Link (CDL) which is a full-duplex, jam-resistant, point-to-point microwave communications system for use in imagery and signals intelligence collection systems. In particular, OPNET, a commercially available network engineering tool is used to model a medium access level remote bridge interface connecting two LANs. The effectiveness of two different load balancing techniques used to distribute traffic over the multiple channels of the CDL has been studied. Also, the effect of different jamming patterns on the bit error rate seen by the users has been studied

A CSMA/CD local area network consists of single server (the channel) and multiple interacting queues of message packets. The message queueing process in a buffered, P-persistent CSMA/CD system is modeled as a multidimensional semi-markov chain. An effective approximation method to compute the mean packet delay in equilibrium is developed, based on the joint probability generating function of the queue length vector at embedded Markov epochs. We also develop a simulation model to validate approximation results. To the best of our knowledge, this work is the first in the literature that enables optimization of the control parameter P for the CSMA/CD system with more than two users. (Author)

A CSMA/CD local area network consists of single server (the channel) and multiple interacting queues of message packets. The message queueing process in a buffered, P-persistent CSMA/CD system is modeled as a multidimensional semi-markov chain. An effective approximation method to compute the mean packet delay in equilibrium is developed, based on the joint probability generating function of the queue length vector at embedded Markov epochs. We also develop a simulation model to validate approximation results. To the best of our knowledge, this work is the first in the literature that enables optimization of the control parameter P for the CSMA/CD system with more than two users. (Author)

Since wireless technology has been used in Local Area Networks (LAN), our networks are easier to build and are more scalable and mobile than legacy structures. While providing these functionalities, Wireless LAN (WLAN)'s have some security vulnerabilities that should be addressed. Failing to examine the security risks of WLAN technology and take the necessary countermeasures may result in unauthorized entry into the legacy local area networks and other attacks. A secure connection to an intranet, which holds critical data and applications, must be the utmost consideration in the effort to protect critical resources. This thesis builds an open-source test-bed for evaluating WLAN security protocols. Moreover, it investigates the suitability of the IEEE 802.1X standard to provide the required security framework to WLANs. This research determines that the IEEE 802.1X could enhance the security level in authentication and privacy by the enabling rekeying process, but would not prevent Denial of Service attacks via unauthenticated management frames.

Since wireless technology has been used in Local Area Networks (LAN), our networks are easier to build and are more scalable and mobile than legacy structures. While providing these functionalities, Wireless LAN (WLAN)'s have some security vulnerabilities that should be addressed. Failing to examine the security risks of WLAN technology and take the necessary countermeasures may result in unauthorized entry into the legacy local area networks and other attacks. A secure connection to an intranet, which holds critical data and applications, must be the utmost consideration in the effort to protect critical resources. This thesis builds an open-source test-bed for evaluating WLAN security protocols. Moreover, it investigates the suitability of the IEEE 802.1X standard to provide the required security framework to WLANs. This research determines that the IEEE 802.1X could enhance the security level in authentication and privacy by the enabling rekeying process, but would not prevent Denial of Service attacks via unauthenticated management frames.

The Department of Defense needs to process data at various levels of security in Local Area Networks (LAN) of computer systems. A formal computer network security model is a necessary first step in certifying a computer system to process classified data. Several computer security models have been developed to identify what is required to enable multilevel certification of a computer system, and a similar model is needed for LANs. The primary objective of this research project is to analyze the requirements of a LAN security model. Conceptual design issues of LAN security modeling are presented in this thesis to identify what must be achieved to ensure security is not violated when data of various levels of security are processed in a local area network. Due to their distributed nature, LANs involve several security issues not addressed in security models (such as the Bell-LaPadula security model) developed for single computer systems. Therefore, modeling of security in LANs and computer networks must be complemented with LAN application and implementation considerations, primarily associated with secure communications channels between LAN subscribers. This thesis analyzes the security requirements of a local area computer network, highlighting the need for a security architecture approach to modeling security in LANs. A textural definition of a prototype LAN security model is presented, and the model's application to hypothetical LAN configurations is discussed.

The Department of Defense needs to process data at various levels of security in Local Area Networks (LAN) of computer systems. A formal computer network security model is a necessary first step in certifying a computer system to process classified data. Several computer security models have been developed to identify what is required to enable multilevel certification of a computer system, and a similar model is needed for LANs. The primary objective of this research project is to analyze the requirements of a LAN security model. Conceptual design issues of LAN security modeling are presented in this thesis to identify what must be achieved to ensure security is not violated when data of various levels of security are processed in a local area network. Due to their distributed nature, LANs involve several security issues not addressed in security models (such as the Bell-LaPadula security model) developed for single computer systems. Therefore, modeling of security in LANs and computer networks must be complemented with LAN application and implementation considerations, primarily associated with secure communications channels between LAN subscribers. This thesis analyzes the security requirements of a local area computer network, highlighting the need for a security architecture approach to modeling security in LANs. A textural definition of a prototype LAN security model is presented, and the model's application to hypothetical LAN configurations is discussed.

The Department of Defense needs to process data at various levels of security in Local Area Networks (LAN) of computer systems. A formal computer network security model is a necessary first step in certifying a computer system to process classified data. Several computer security models have been developed to identify what is required to enable multilevel certification of a computer system, and a similar model is needed for LANs. The primary objective of this research project is to analyze the requirements of a LAN security model. Conceptual design issues of LAN security modeling are presented in this thesis to identify what must be achieved to ensure security is not violated when data of various levels of security are processed in a local area network. Due to their distributed nature, LANs involve several security issues not addressed in security models (such as the Bell-LaPadula security model) developed for single computer systems. Therefore, modeling of security in LANs and computer networks must be complemented with LAN application and implementation considerations, primarily associated with secure communications channels between LAN subscribers. This thesis analyzes the security requirements of a local area computer network, highlighting the need for a security architecture approach to modeling security in LANs. A textural definition of a prototype LAN security model is presented, and the model's application to hypothetical LAN configurations is discussed.

Thesis advisor, Tri T. Ha

IC Datasheet: 1993 Local Area Networks

This thesis investigates those aspects of network performance evaluation thought to pertain specifically to strategic performance management evaluation of the Navy's Stock Point Logistics Integrated Communications Environment (SPLICE) local area networks at stock point and inventory control point sites- Background is provided concerning the SPLICE Project, strategic management, computer performance evaluation tools, computer and local area network performance metrics and performance evaluation methodology, capacity planning, the SPLICE LAN communications subnetwork hardware and software, and internetworking of SPLICE LAN's via the Defense Data Network (DDN) . These topics, relevant case studies, and observations of one SPLICE LAN site are used to arrive at implications and recommendations applicable for improving the future generic SPLICE LAN planning and performance.

Seminar workbook for Data-Tech's Local Area Networking course, ca 1991.

Seminar workbook for Data-Tech's Local Area Networking course, ca 1991.

Local area networks have come into widespread use for computer communications. Together with the trend towards digital transmission of telephone signals, this has sparked interest in the use of computer networks for the transmission of integrated voice/data traffic. This work addresses two related aspects of local area network performance, a detailed characterization of the performance of Carrier Sense Multiple Access with Collision Detection (CSMA/CD), and the comparative performance of several broadcast bus networks with voice/data traffic. While prior analysis of CSMA/CD has shown that the protocol achieves good performance with data traffic over a range of conditions, the widely used IEEE 802.3 (Ethernet) implementation of the protocol has several aspects that are not easily amenable to mathematical analysis. These include the binary-exponential back-off algorithm used upon collision, the number of buffers per station, and the physical distribution of stations. Performance measurements on operational 3 and 10 Mb/s networks are presented. These demonstrate that the protocol achieves high throughput with data traffic when the packet transmission time is long compared to the propagation delay, as predicted by analysis. However, at 10 Mb/s, with short packets on the order of 64 bytes, performance is poorer. The inflexibility of measurement leads to the use of simulation to further study the behaviour of the Ethernet.

Local area networks have come into widespread use for computer communications. Together with the trend towards digital transmission of telephone signals, this has sparked interest in the use of computer networks for the transmission of integrated voice/data traffic. This work addresses two related aspects of local area network performance, a detailed characterization of the performance of Carrier Sense Multiple Access with Collision Detection (CSMA/CD), and the comparative performance of several broadcast bus networks with voice/data traffic. While prior analysis of CSMA/CD has shown that the protocol achieves good performance with data traffic over a range of conditions, the widely used IEEE 802.3 (Ethernet) implementation of the protocol has several aspects that are not easily amenable to mathematical analysis. These include the binary-exponential back-off algorithm used upon collision, the number of buffers per station, and the physical distribution of stations. Performance measurements on operational 3 and 10 Mb/s networks are presented. These demonstrate that the protocol achieves high throughput with data traffic when the packet transmission time is long compared to the propagation delay, as predicted by analysis. However, at 10 Mb/s, with short packets on the order of 64 bytes, performance is poorer. The inflexibility of measurement leads to the use of simulation to further study the behaviour of the Ethernet.

Local area networks have come into widespread use for computer communications. Together with the trend towards digital transmission of telephone signals, this has sparked interest in the use of computer networks for the transmission of integrated voice/data traffic. This work addresses two related aspects of local area network performance, a detailed characterization of the performance of Carrier Sense Multiple Access with Collision Detection (CSMA/CD), and the comparative performance of several broadcast bus networks with voice/data traffic. While prior analysis of CSMA/CD has shown that the protocol achieves good performance with data traffic over a range of conditions, the widely used IEEE 802.3 (Ethernet) implementation of the protocol has several aspects that are not easily amenable to mathematical analysis. These include the binary-exponential back-off algorithm used upon collision, the number of buffers per station, and the physical distribution of stations. Performance measurements on operational 3 and 10 Mb/s networks are presented. These demonstrate that the protocol achieves high throughput with data traffic when the packet transmission time is long compared to the propagation delay, as predicted by analysis. However, at 10 Mb/s, with short packets on the order of 64 bytes, performance is poorer. The inflexibility of measurement leads to the use of simulation to further study the behaviour of the Ethernet.

Local area networks have come into widespread use for computer communications. Together with the trend towards digital transmission of telephone signals, this has sparked interest in the use of computer networks for the transmission of integrated voice/data traffic. This work addresses two related aspects of local area network performance, a detailed characterization of the performance of Carrier Sense Multiple Access with Collision Detection (CSMA/CD), and the comparative performance of several broadcast bus networks with voice/data traffic. While prior analysis of CSMA/CD has shown that the protocol achieves good performance with data traffic over a range of conditions, the widely used IEEE 802.3 (Ethernet) implementation of the protocol has several aspects that are not easily amenable to mathematical analysis. These include the binary-exponential back-off algorithm used upon collision, the number of buffers per station, and the physical distribution of stations. Performance measurements on operational 3 and 10 Mb/s networks are presented. These demonstrate that the protocol achieves high throughput with data traffic when the packet transmission time is long compared to the propagation delay, as predicted by analysis. However, at 10 Mb/s, with short packets on the order of 64 bytes, performance is poorer. The inflexibility of measurement leads to the use of simulation to further study the behaviour of the Ethernet.

This report describes the development of an optical Time-Division Multiple-Access (TDMA) interconnect suitable for applications in local-area and micro-area networks. The advantages of using time-division techniques instead of frequency-division, wavelength-division, or code-division techniques in a shared-medium environment are discussed in detail. Furthermore, a detailed description of the TDMA architecture is presented along with various experiments pertaining to the actual components needed to implement the system. Finally, experimental data is presented for an actual optical TDMA test bed. The experimental data demonstrates the feasibility of the architecture, and shows that currently the system has the capability to accommodate up to 50 channels. The bit-error-rate per channel was measured to be less than 10 to the minus ninth power for pseudo-random bit-sequences.

This report describes the development of an optical Time-Division Multiple-Access (TDMA) interconnect suitable for applications in local-area and micro-area networks. The advantages of using time-division techniques instead of frequency-division, wavelength-division, or code-division techniques in a shared-medium environment are discussed in detail. Furthermore, a detailed description of the TDMA architecture is presented along with various experiments pertaining to the actual components needed to implement the system. Finally, experimental data is presented for an actual optical TDMA test bed. The experimental data demonstrates the feasibility of the architecture, and shows that currently the system has the capability to accommodate up to 50 channels. The bit-error-rate per channel was measured to be less than 10 to the minus ninth power for pseudo-random bit-sequences.

The Langley Research Center's (LaRC) Local Area Network (LAN) effort is discussed. LaRC initiated the development of a LAN to support a growing distributed computing environment at the Center. The purpose of the network is to provide an improved capability (over inteactive and RJE terminal access) for sharing multivendor computer resources. Specifically, the network will provide a data highway for the transfer of files between mainframe computers, minicomputers, work stations, and personal computers. An important influence on the overall network design was the vital need of LaRC researchers to efficiently utilize the large CDC mainframe computers in the central scientific computing facility. Although there was a steady migration from a centralized to a distributed computing environment at LaRC in recent years, the work load on the central resources increased. Major emphasis in the network design was on communication with the central resources within the distributed environment. The network to be implemented will allow researchers to utilize the central resources, distributed minicomputers, work stations, and personal computers to obtain the proper level of computing power to efficiently perform their jobs.

The Langley Research Center's (LaRC) Local Area Network (LAN) effort is discussed. LaRC initiated the development of a LAN to support a growing distributed computing environment at the Center. The purpose of the network is to provide an improved capability (over inteactive and RJE terminal access) for sharing multivendor computer resources. Specifically, the network will provide a data highway for the transfer of files between mainframe computers, minicomputers, work stations, and personal computers. An important influence on the overall network design was the vital need of LaRC researchers to efficiently utilize the large CDC mainframe computers in the central scientific computing facility. Although there was a steady migration from a centralized to a distributed computing environment at LaRC in recent years, the work load on the central resources increased. Major emphasis in the network design was on communication with the central resources within the distributed environment. The network to be implemented will allow researchers to utilize the central resources, distributed minicomputers, work stations, and personal computers to obtain the proper level of computing power to efficiently perform their jobs.

This report describes various techniques used for network management and frequency allocation. Modern techniques such as packet switching, data compression, and spread spectrum are explained. The United States Department of Defense involvement in this area is covered as well as areas for future growth.

This thesis investigates the stability of the random multiaccess protocols, slotted CSMA and slotted CSMA/CD, utilizing one power level and two power levels to create beneficial power capture effect. Use of more than two equally spaced power levels provides no significant improvement in the throughput achievable when realistic capture thresholds are considered. The investigation centers on a technique known as pseudo-Bayesian stability. Another task of this thesis is to stabilize multichannel slotted CSMA and slotted CSMA/CD with pseudo-Bayesian technique. The multichannel slotted CSMA and slotted CSMA/CD show a large improvement in throughput over a traditional single channel with a combined bit rate.

Since wireless technology has been used in Local Area Networks (LAN), our networks are easier to build and are more scalable and mobile than legacy structures. While providing these functionalities, Wireless LAN (WLAN)'s have some security vulnerabilities that should be addressed. Failing to examine the security risks of WLAN technology and to take the necessary countermeasures may result in unauthorized entry into the legacy local area networks and other attacks. A secure connection to an intranet, which holds critical data and applications, must be the utmost consideration in the effort to protect critical resources. This thesis builds an open-source test-bed for evaluating WLAN security protocols. Moreover, it investigates the suitability of the IEEE 802.1X standard to provide the required security framework to WLANs. This research determines that the IEEE 802.1X could enhance the security level in authentication and privacy by enabling the rekeying process but would not prevent Denial of Service attacks via unauthenticated management frames.

Probability & statistics

Probability & statistics

Probability & statistics

Probability & statistics

Probability & statistics

Probability & statistics

This thesis discusses the development of an interconnection of Stock Point Logistics Integrated Communications Environment (SPLICE) local area networks with the Defense Data Network (DDN). The interconnection is done through what is called the National Communications (NC) module. After an introduction to SPLICE and DDN, a User's Manual for NC is presented, defining the environment and interfaces of NC. Then, the activation behind the NC design and its operational context is explained in detail. Implementation issues are discussed next. Finally, the structure of NC is depicted by NIPO charts, pseudo-code and Ada language constructs.

This thesis discusses the development of an interconnection of Stock Point Logistics Integrated Communications Environment (SPLICE) local area networks with the Defense Data Network (DDN). The interconnection is done through what is called the National Communications (NC) module. After an introduction to SPLICE and DDN, a User's Manual for NC is presented, defining the environment and interfaces of NC. Then, the activation behind the NC design and its operational context is explained in detail. Implementation issues are discussed next. Finally, the structure of NC is depicted by NIPO charts, pseudo-code and Ada language constructs.

The design and the implementation of a real-time communication network has to meet goals of fault-free and timely delivery of messages, as defined by the applications served by this network. The time constraints of the applications are projected as stringent constraints on the local knowledge of time. However, the local knowledge of time in a distributed system requires the use of the communication network. The accuracy and coherence of this knowledge depend on the way clocks are synchronized. Therefore, the performance of clock synchronization algorithms due to the communication network, is a good criterion for analyzing the adequacy of a particular network architecture to real-time application. This paper examines the adequacy of LAN architecture for real-time applications through a delay model of a typical LAN. The model is applied to various clock synchronization algorithms, and error estimates for these algorithms are derived. An efficient environment, in which the uncertainties in message communication elapsed time is significantly reduced, is then described for layered protocol architecture. In addition, it is shown that predictable communication elapsed time can be compensated for in synchronization algorithms, significantly reducing the errors of these algorithms.

The design and the implementation of a real-time communication network has to meet goals of fault-free and timely delivery of messages, as defined by the applications served by this network. The time constraints of the applications are projected as stringent constraints on the local knowledge of time. However, the local knowledge of time in a distributed system requires the use of the communication network. The accuracy and coherence of this knowledge depend on the way clocks are synchronized. Therefore, the performance of clock synchronization algorithms due to the communication network, is a good criterion for analyzing the adequacy of a particular network architecture to real-time application. This paper examines the adequacy of LAN architecture for real-time applications through a delay model of a typical LAN. The model is applied to various clock synchronization algorithms, and error estimates for these algorithms are derived. An efficient environment, in which the uncertainties in message communication elapsed time is significantly reduced, is then described for layered protocol architecture. In addition, it is shown that predictable communication elapsed time can be compensated for in synchronization algorithms, significantly reducing the errors of these algorithms.

The design and the implementation of a real-time communication network has to meet goals of fault-free and timely delivery of messages, as defined by the applications served by this network. The time constraints of the applications are projected as stringent constraints on the local knowledge of time. However, the local knowledge of time in a distributed system requires the use of the communication network. The accuracy and coherence of this knowledge depend on the way clocks are synchronized. Therefore, the performance of clock synchronization algorithms due to the communication network, is a good criterion for analyzing the adequacy of a particular network architecture to real-time application. This paper examines the adequacy of LAN architecture for real-time applications through a delay model of a typical LAN. The model is applied to various clock synchronization algorithms, and error estimates for these algorithms are derived. An efficient environment, in which the uncertainties in message communication elapsed time is significantly reduced, is then described for layered protocol architecture. In addition, it is shown that predictable communication elapsed time can be compensated for in synchronization algorithms, significantly reducing the errors of these algorithms.

Having covered the operation of the Internet's WAN (Wide Area Network) technology in the past two weeks, this week Leo and Steve turn to discussing the way Local Area Networks (LANs) operate and how they interface with the Internet WAN. We address the configuration of subnet masks, default gateways, and DHCP to explain how packets are routed among machines and gateways within a LAN.

This thesis is an in-depth evaluation of the current wireless Local Area Network (LAN) technologies. Wireless LANs consist of three technologies; they are infrared light, microwave, and spread spectrum. When the first wireless LANs were introduced, they were unfavorably labeled slow, expensive, and unreliable. The wireless LANs of today are competitively priced, more secure, easier to install, and provide equal to or greater than the data throughput of unshielded twisted pair cable. Wireless LANs are best suited for organizations that move office staff frequently, buildings that have historical significance, or buildings that have asbestos. Additionally, an organizations may realize a cost savings of between $300 to $1,200 each time a node is moved. Current wireless LAN technologies have a positive effect on LAN standards being developed by the Defense Information System Agency (DISA). DoD as a whole is beginning to focus on wireless LANs and mobile communications. If system managers want to remain successful, they need to stay abreast of this technology.

This thesis is an in-depth evaluation of the current wireless Local Area Network (LAN) technologies. Wireless LANs consist of three technologies; they are infrared light, microwave, and spread spectrum. When the first wireless LANs were introduced, they were unfavorably labeled slow, expensive, and unreliable. The wireless LANs of today are competitively priced, more secure, easier to install, and provide equal to or greater than the data throughput of unshielded twisted pair cable. Wireless LANs are best suited for organizations that move office staff frequently, buildings that have historical significance, or buildings that have asbestos. Additionally, an organizations may realize a cost savings of between $300 to $1,200 each time a node is moved. Current wireless LAN technologies have a positive effect on LAN standards being developed by the Defense Information System Agency (DISA). DoD as a whole is beginning to focus on wireless LANs and mobile communications. If system managers want to remain successful, they need to stay abreast of this technology.

From the bitsavers.org collection, a scanned-in computer-related document. ibm :: lan :: GG24-3071-0 IBM Local Area Networks in an Office System Environment Aug86