Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, Dec. 2001. / Thesis advisor: John McEachen. "December 2001." Includes bibliographical references (p. 95). Also available online.

International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / We need to begin to define what the future of point-to-point telemetry will be in the new world of wireless communications, increasing bandwidth requirements, the integration of test and training, and modeling and simulation (M&S) interacting with open air ranges. The Advanced Range Telemetry Program will introduce several new technologies to the telemetry community over the next several years, how will we use and build on them for the future? What kind of architecture will we need to be able to interact with the M&S and Training communities? How do we create that architecture and to what use would it be put by a test program? The answer, we believe, is to build the equivalent of a network in the sky. An extension of the Internet, in simplistic terms. The system under test (SUT), or the systems in training would become nodes of a large interactive network. Instead of the SUT being treated as something outside the sphere of control for the range, the SUTs onboard instrumentation systems would become an integral part of the greater range complex. This paper will address what the architecture of a real-time telemetry network might look like and how it could be implemented within the telemetry community.

ITC/USA 2015 Conference Proceedings / The Fifty-First Annual International Telemetering Conference and Technical Exhibition / October 26-29, 2015 / Bally's Hotel & Convention Center, Las Vegas, NV / The use of wireless data networks is ubiquitous in the consumer world. They have gained significant traction due to advantages afforded by the lack of wires. These same advantages can prove valuable in Flight Test for data acquisition. Sensor nodes are ideal candidates for low bandwidth wireless networks. Located in remote, hard to reach and hostile environments, wirelessly acquiring data from such sensor can solve a number of existing issues for FTI engineers. Implementing such wireless communication introduces a number of challenges such as guaranteeing reliable transfer of the sensor data and time synchronization of the remote nodes. This paper addresses wireless sensor acquisition, the associated challenges and discusses approaches and solutions to these problems.

No description available.

In this paper, we propose a novel information-theoretical fairness metric to evaluate the fairness of bandwidth allocation to distributed nodes in local area network. When the source traffic pattern is fixed, the proposed metric is a mapping from the set of all medium access control (MAC) protocols to the interval [0,1] in the real line such that a larger value corresponds to a MAC protocol that allocates bandwidth more fairly. The metric is applicable for a wide range of medium access control schemes including those in which the packet lengths are not identical and/or multipacket reception (MPR) capability is available. To verify the correctness of the novel metric, we use it to evaluate the fairness levels of an IEEE 802.11 wireless LAN composed of homogeneous or heterogeneous nodes. Our simulations indicate that for the IEEE 802.11 protocol, the short-term fairness level is low while the long-term fairness level is high. The information-theoretical fairness metric leads to a conclusion that is consistent to the previous finding in the lecture.

The IEEE 802.11 wireless local area network (WLAN) standard supports multiple transmission modes. However, the higher mandatory data rate mode does not necessarily yield higher throughput. This research started from the relationship between the link throughput and the channel's carrier-to-noise (C/N) ratio. Two algorithms are proposed, a throughput optimization and transmitter power saving (TOTPS) algorithm and an extended throughput optimization and transmitter power saving (ETOTPS) algorithm, based on the knowledge of the C/N ratio at the receiver. In particular, we take the approach of adjusting link parameters like transmitter power and transmission mode to achieve the maximum throughput at different C/N values. Since the TOTPS algorithm tends to reduce the transmitter power without degrading the link throughput, transmitter power can be saved. This not only prolongs battery life, which is critical in ad hoc wireless networks, but also reduces the potential interference to neighboring wireless network systems. The ETOTPS algorithm, on the other hand, aims for higher throughput by trading in more transmitter power. This is particularly desired for high-speed data transfer in an emergency situation. Both algorithms are developed to be applied to IEEE 802.11b, IEEE 802.11a and IEEE 802.11g links. / Ph. D.

This paper is a study and comparison between the two Wireless LAN (WLAN) standards HiperLAN/2 and IEEE 802.11a. WLANs are used instead or together with ordinary LANs to increase mobility in for example an office. HiperLAN/2 is an European standard developed by ETSI and the IEEEs standard is American. A WLAN-card consists roughly of a Medium Access Control (MAC), Physichal layer (PHY) and an antenna. The antenna is the same for the different standards. Both standards operates at 5.4 GHz with a maximum transmission rate at 54 Mbit/s and they use OFDM to modulate the signal. This means that the physical layer in the two standards is similar. The differences between the standards are in the Medium Access Control (MAC) layer. HiperLAN/2 has a much more complex MAC since it is developed with the starting point in cellular phones. Therefore this MAC is not very similar to ETHERNET that is the protocol used by regular network. On the other hand it is built to be compatible with cellular phones and other applications. The 802.11a MAC is very much the same as in the 802.11b standard that is the most used standard at present. The difference is that 802.11a can send at much higher data rates. This MAC is build with starting point in ETHERNET so it has a similar interface to the computer. This makes it less complex. The different MACs can provide different services. The greatest difference is that 802.11a can use a distributed send mode where any STA can send if the medium is idle. This reminds a lot of ETHERNET but they use different methods to sense if the medium is idle. In HiperLAN/2 are all transmissions scheduled by the AP. 802.11a can operate in a similar way but at the moment this mode is not as fully developed as in HiperLAN/2. There are working groups in IEEE that works toward an improvement of 802.11a so it can use queues with different priorities, this is already implemented in HiperLAN/2. Another important issue in wireless environment is security. Both standards use encryption to protect their messages. The difference is that HiperLAN/2 changes their encryption key for every connection where 802.11a uses the same key the whole time. This gives HiperLAN/2 a better security with todays standard but thereare working groups dealing with implementing key-exchange functions and Kerberos use in 802.11a. Chapter 8 is a description of a program that we developed in C++. The program is used to monitor the different registers and ports a WLAN-card use. It is written for a 802.11b card and should be used together with Windows 2000. The source code can be found in appendix C.

The Distributed Coordination Function (DCF) which uses Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) and binary slotted exponential backoff scheme is the basis of the IEEE 802.11 Medium Access Control (MAC) protocol. However, the DCF is not suitable for real-time traffic control since the backoff scheme may cause huge frame delay and jitter. We propose a modified DCF which uses a forward backoff scheme to remedy this disadvantage. In addition, a call admission control (CAC) is also proposed. Our protocol can guarantee service qualities such as the network throughput, frame delay, and jitter for real-time traffics. Besides, the modified DCF is still compliant with the IEEE 802.11 standard. Simulation results have shown that our method performs better than other DCF disciplines.

This thesis consisted of three parts. Part 1 introduced the design procedure of an RF transceiver modules for IEEE 802.11b WLAN system. It contained the selection of RF architectures, frequency planning, and the receiver link budget analysis flow. Part 2 focused on the implementation of each stage in the whole RF link. The design considerations of choosing passive elements and the parasitic effect of the evaluation board are discussed. Part 3 integrated the whole RF transceiver module and estimated the performance of this module through the link budget analysis method. Furthermore, a complete specification measurement was accomplished by using the standard test signals. The test results confirmed with the budget results, and also pass the specification of IEEE 802.11b WLAN system.

<p>This paper is a study and comparison between the two Wireless LAN (WLAN) standards HiperLAN/2 and IEEE 802.11a. WLANs are used instead or together with ordinary LANs to increase mobility in for example an office. HiperLAN/2 is an European standard developed by ETSI and the IEEEs standard is American. </p><p>A WLAN-card consists roughly of a Medium Access Control (MAC), Physichal layer (PHY) and an antenna. The antenna is the same for the different standards. </p><p>Both standards operates at 5.4 GHz with a maximum transmission rate at 54 Mbit/s and they use OFDM to modulate the signal. This means that the physical layer in the two standards is similar. </p><p>The differences between the standards are in the Medium Access Control (MAC) layer. HiperLAN/2 has a much more complex MAC since it is developed with the starting point in cellular phones. Therefore this MAC is not very similar to ETHERNET that is the protocol used by regular network. On the other hand it is built to be compatible with cellular phones and other applications. </p><p>The 802.11a MAC is very much the same as in the 802.11b standard that is the most used standard at present. The difference is that 802.11a can send at much higher data rates. This MAC is build with starting point in ETHERNET so it has a similar interface to the computer. This makes it less complex. </p><p>The different MACs can provide different services. The greatest difference is that 802.11a can use a distributed send mode where any STA can send if the medium is idle. This reminds a lot of ETHERNET but they use different methods to sense if the medium is idle. In HiperLAN/2 are all transmissions scheduled by the AP. 802.11a can operate in a similar way but at the moment this mode is not as fully developed as in HiperLAN/2. There are working groups in IEEE that works toward an improvement of 802.11a so it can use queues with different priorities, this is already implemented in HiperLAN/2. </p><p>Another important issue in wireless environment is security. Both standards use encryption to protect their messages. The difference is that HiperLAN/2 changes their encryption key for every connection where 802.11a uses the same key the whole time. This gives HiperLAN/2 a better security with todays standard but thereare working groups dealing with implementing key-exchange functions and Kerberos use in 802.11a. Chapter 8 is a description of a program that we developed in C++. The program is used to monitor the different registers and ports a WLAN-card use. It is written for a 802.11b card and should be used together with Windows 2000. The source code can be found in appendix C.</p>